Squeeze‐film characteristics between a long cylinder and an infinite flat plate system are analysed. Ferrofluid (FF) lubricant controlled by transverse uniformly strong magnetic field is used for ...reducing wear and prolonging life of the system. The modified combined Reynolds equation is derived using two different FF flow models (Shliomis and Jenkins), and continuity equation. The expression for dimensionless film‐pressure, load‐carrying capacity and squeeze time are derived and calculated numerically for different control parameters. The results show significant improvement in the performance of the system when smaller value of minimum film thickness is chosen. Moreover, the phenomenon can be simulated by both the models equally with proper choice of the parameters.
In this paper, porous-roughness effects on different circular discs squeeze film bearing designs lubricated with ferrofluid (FF) are studied. Using FF flow model by Rosensweig and continuity equation ...for the film as well as porous region, modified stochastic Reynolds–Darcy equation is derived for variable magnetic field by considering effects of porosity together with roughness (circumferential and radial) at the lower disc and rotations of both the discs, under the assumption of validity of the Darcy’s law in the porous region. This equation is then applied to predict and compare performances of parallel, exponential, secant and mirror image of secant squeeze film bearing designs for load-carrying capacity
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The automotive market is currently shifting away from traditional vehicles reliant on internal combustion engines, favoring battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), and ...plug-in hybrid electric vehicles (PHEVs). The widespread acceptance of these vehicles, especially without government subsidies, hinges on market dynamics, particularly customers opting for vehicles with the lowest overall cost of ownership. This paper aims to model the total cost of ownership for various powertrains, encompassing conventional vehicles, HEVs, PHEVs, and BEVs, focusing on both sedans and sports utility vehicles. The modeling uses vehicle dynamics to approximate the fuel and electricity consumption rates for each powertrain. Following this, the analysis estimates the purchase cost and the lifetime operational cost for each vehicle type, factoring in average daily mileage. As drivers consider vehicle replacements, their choice tends to lean towards the most economical option, especially when performance metrics (e.g., range, acceleration, and payload) are comparable across the choices. The analysis seeks to determine the percentage of drivers likely to choose each vehicle type based on their specific driving habits. Advances in battery technology will reduce the battery weight and cost; further, the cost of electricity will decrease as more renewable energy sources will be integrated into the grid. In turn, the total cost of ownership will decrease for the electrified vehicles. By following battery trends, this study is able to model the makeup of the automotive market over time as it transitions from fossil-fuel based vehicles to fully electric vehicles. The model finds until the cost of batteries and electricity is significantly reduced, the composition of the vehicle market is a mixture of all vehicle types.
The transportation industry’s transition to carbon neutrality is essential for addressing sustainability concerns. This study details a model for calculating the carbon footprint of the ...transportation sector as it progresses towards carbon neutrality. The model aims to support policymakers in estimating the potential impact of various decisions regarding transportation technology and infrastructure. It accounts for energy demand, technological advancements, and infrastructure upgrades as they relate to each transportation market: passenger vehicles, commercial vehicles, aircraft, watercraft, and trains. A technology roadmap underlies this model, outlining anticipated advancements in batteries, hydrogen storage, biofuels, renewable grid electricity, and carbon capture and sequestration. By estimating the demand and the technologies that comprise each transportation market, the model estimates carbon emissions. Results indicate that based on the technology roadmap, carbon neutrality can be achieved by 2070 for the transportation sector. Furthermore, the model found that carbon neutrality can still be achieved with slippage in the technology development schedule; however, delays in infrastructure updates will delay carbon neutrality, while resulting in a substantial increase in the cumulative carbon footprint of the transportation sector.
Background
The rate of change in the incidence of colorectal cancer (CRC) among persons younger than 50 years in the United States appears to vary by demographics, tumor location, and geography. This ...study analyzed data from all 50 states to examine recent changes in the incidence of CRC among persons younger than 50 years and to identify key subgroups with disproportionate risk.
Methods
Annual incidence rates for CRC, colon cancer, and rectal cancer in persons aged 20 to 49 years were extracted from the US Cancer Statistics for the period 2001‐2017. Secular trends were examined overall and by age group, sex, race/ethnicity, stage, and state. Joinpoint regression was used to compute annual percent changes and average annual percent changes (AAPCs) as well as corresponding 95% confidence intervals (95% CIs).
Results
The incidence of CRC increased by 1.27% (95% CI, 0.95%‐1.60%) annually from 2001 to 2012 and by 3.00% (95% CI, 2.06%‐3.95%) annually from 2012 to 2017. AAPCs for the period 2001‐2017 were higher among persons aged 20 to 24 years (AAPC, 6.62%; 95% CI, 3.86%‐9.45%) in comparison with other age groups and higher among non‐Hispanic Whites (AAPC, 2.38%; 95% CI, 1.98%‐2.79%) in comparison with other racial/ethnic groups. In 2001‐2002, only 1 state had an age‐standardized incidence rate > 13.0 per 100,000, but this number increased to 32 states by 2016‐2017.
Conclusions
CRC rates among US adults aged 20 to 49 years increased from 2001 to 2017, with the fastest increases observed from 2012 to 2017. Increases were observed among the youngest age groups, among non‐Hispanic Whites, and in states in the West, Midwest, and Rocky Mountain regions. Increasing rates across all tumor stages suggest a real increase in CRC incidence.
The incidence of early‐onset colorectal cancer is gradually increasing throughout the United States, with the greatest rise occurring in the Western United States. The rise in the incidence of early‐onset colorectal cancer has affected races and ethnicities disproportionately and may inform future decisions regarding tailored screening recommendations.
Despite tremendous interest in modulating the microbiome to improve health, the association between diet and the colonic mucosa–associated gut microbiome in healthy individuals has not been examined.
...To investigate the associations between Healthy Eating Index (HEI)–2005 and the colonic mucosa–associated microbiota.
In this cross-sectional observational study, we analyzed bacterial community composition and structure using 16S rRNA gene (V4 region) sequencing of 97 colonic mucosal biopsies obtained endoscopically from different colon segments of 34 polyp-free participants. Dietary consumption was ascertained using an FFQ. Differences in α- and β-diversity and taxonomic relative abundances between the higher and lower score of total HEI and its components were compared, followed by multivariable analyses.
The structure of the microbiota significantly differed by the scores for total HEI, total and whole fruits (HEI 1 and HEI 2), whole grains (HEI 6), milk products and soy beverages (HEI 7), and solid fat, alcohol, and added sugar (HEI 12). A lower score for total HEI and HEIs 2, 7, and 12 was associated with significantly lower richness. A lower score for total HEI was associated with significantly reduced relative abundance of Parabacteroides, Roseburia, and Subdoligranulum but higher Fusobacterium. A lower score for HEI 2 was associated with lower Roseburia but higher Bacteroides. A lower score for HEI 7 was associated with lower Faecalibacterium and Fusobacterium but higher Bacteroides. A lower score for HEI 12 was associated with lower Subdoligranulum but higher Escherichia and Fusobacterium (false discovery rate–adjusted P values <0.05). The findings were confirmed by multivariate analysis. Less abundant bacteria such as Alistipes, Odoribacter, Bilophila, and Tyzzerella were also associated with dietary quality.
A lower score for total HEI–2005 was significantly associated with reduced relative abundance of potentially beneficial bacteria but increased potentially harmful bacteria in the colonic mucosa of endoscopically normal individuals.
Patients with cirrhosis have abnormal coagulation indices such as a high international normalized ratio and low platelet count, but these do not correlate well with periprocedural bleeding risk. We ...sought to develop a consensus among the multiple stakeholders in cirrhosis care to inform process measures that can help improve the quality of the periprocedural management of coagulopathy in cirrhosis. We identified candidate process measures for periprocedural coagulopathy management in multiple contexts relating to the performance of paracentesis and upper endoscopy. An 11-member panel with content expertise was convened. It included nominees from professional societies for interventional radiology, transfusion medicine, and anesthesia as well as representatives from hematology, emergency medicine, transplant surgery, and community practice. Each measure was evaluated for agreement using a modified Delphi approach (3 rounds of rating) to define the final set of measures. Out of 286 possible measures, 33 measures made the final set. International normalized ratio testing was not required for diagnostic or therapeutic paracentesis as well as diagnostic endoscopy. Plasma transfusion should be avoided for all paracenteses and diagnostic endoscopy. No consensus was achieved for these items in therapeutic intent or emergent endoscopy. The risks of prophylactic platelet transfusions exceed their benefits for outpatient diagnostic paracentesis and diagnostic endosopies. For the other procedures examined, the risks outweigh benefits when platelet count is >20,000/mm 3 . It is uncertain whether risks outweigh benefits below 20,000/mm 3 in other contexts. No consensus was achieved on whether it was permissible to continue or stop systemic anticoagulation. Continuous aspirin was permissible for each procedure. Clopidogrel was permissible for diagnostic and therapeutic paracentesis and diagnostic endoscopy. We found many areas of consensus that may serve as a foundation for a common set of practice metrics for the periprocedural management of coagulopathy in cirrhosis.
Hyperechoic breast lesions are relatively uncommon, constituting only 0.6-6% of all breast masses and 0.6% of all biopsied lesions. The majority of these lesions are benign. There are rare ...malignancies that can present as hyperechoic masses and careful ultrasonographic assessment must be employed to avoid misdiagnosis.1 We discuss the case of a 67-year-old female patient with a strong family history of breast and ovarian cancer, who presented with one such rare breast cancer in a hyperechoic mass.
To review available evidence for use of cone-beam CT during transcatheter arterial chemoembolization in hepatocellular carcinoma (HCC) for detection of tumor and feeding arteries.
Literature searches ...were conducted from inception to May 15, 2016, in PubMed (MEDLINE), Scopus, and Cochrane Central Register of Controlled Trials. Searches included "cone beam," "CBCT," "C-arm," "CACT," "cone-beam CT," "volumetric CT," "volume computed tomography," "volume CT," AND "liver," "hepatic*," "hepatoc*." Studies that involved adults with HCC specifically and treated with transcatheter arterial chemoembolization that used cone-beam CT were included.
Inclusion criteria were met by 18 studies. Pooled sensitivity of cone-beam CT for detecting tumor was 90% (95% confidence interval CI, 82%-95%), whereas pooled sensitivity of digital subtraction angiography (DSA) for tumor detection was 67% (95% CI, 51%-80%). Pooled sensitivity of cone-beam CT for detecting tumor feeding arteries was 93% (95% CI, 91%-95%), whereas pooled sensitivity of DSA was 55% (95% CI, 36%-74%).
Cone-beam CT can significantly increase detection of tumors and tumor feeding arteries during transcatheter arterial chemoembolization. Cone-beam CT should be considered as an adjunct tool to DSA during transcatheter arterial chemoembolization treatments of HCC.
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