Unit Density Research Articles

Clinical value of deep vein thrombosis density on pre-contrast and post-contrast lower-extremity CT for prediction of pulmonary thromboembolism.

There was a lack of studies assessing the relationship between deep vein thrombosis (DVT) Hounsfield unit (HU) density and pulmonary thromboembolism (PTE). To evaluate the clinical value of DVT density measured on pre- and post-contrast lower-extremity computed tomography (CT) for the prediction of PTE. From 2017 to 2021, patients who underwent pulmonary CT angiography within one week after diagnosis of DVT on lower-extremity CT were included in this retrospective study. Then, the patients without PTE were included in "DVT group" and those with both DVT and PTE were included in the "DVT-PTE group." The DVT HU density was measured by drawing free-hand region of interests (ROIs) within the thrombus at the most proximal filling defect level. A receiver operating characteristic (ROC) analysis was used to evaluate the predictive value of DVT density for the risk of PTE. This study included a total of 94 patients (DVT group: n=56; DVT-PTE group: m=38). DVT density was significantly higher in the DVT-PTE group than the DVT group in both pre-contrast (53.5 ± 6.2 HU vs. 44.1 ± 7.9 HU; P < 0.001) and post-contrast CT (67.0 ± 8.6 HU vs. 57.1 ± 10.6 HU; P < 0.001). ROC analysis revealed that the area under curve, sensitivity, and specificity for predicting the risk of PTE were 0.739, 71.1%, and 64.2%, respectively, at a DVT density cutoff of 48.2 HU on pre-contrast CT and were 0.779, 73.7%, and 69.6% at a DVT density cutoff of 61.8 HU on post-contrast CT. The DVT density on both pre- and post-contrast CT could be a predictive factor of PTE.

Real-time crowd formation control in virtual scenes

This paper presents a formation control system that can be applied in many areas under defined conditions. The system allows users to simplify interaction and quickly complete formation arrangements in virtual scenarios. At the same time, the system allows the user to input specific formations to meet requirements, such as war formations in video games or formation arrangements for stage performances. It also recognizes user input through a human–computer interaction method based on gesture recognition and finds the best corresponding formation from a library of predefined and user-defined formations. The system ensures real-time user interaction and control by automatically scaling the group size and controlling the group movement according to the unit density. During formation changes, the minimum energy principle is applied to determine the ideal position of each agent in the target formation to increase the efficiency of its movement. In addition, formation stability is maintained during collision avoidance by combining potential obstacle fields with a rigid formation network. Finally, the proposed formation system is tested qualitatively and compared quantitatively with the execution efficiency of some existing interactive formation methods. The experimental results show that the method can effectively implement formation control in a virtual scene. It can automatically avoid obstacles and maintain the formation during the formation morphing process.

Exploring the nonlinear effects of ridesharing on public transit usage: A case study of San Diego

The emergence of ridesharing services might complement or substitute public transit systems, leading to intricate relationships between the two services. However, limited studies focused on the nonlinear effects of ridesharing use frequency on public transit usage. Therefore, this paper investigated such nonlinear effects using the hierarchical negative binomial generalized additive model (HNBGAM), with the latest publicly available National Household Travel Survey (NHTS) dataset. The negative binomial and hierarchical negative binomial generalized linear models were also developed for comparison with the HNBGAM. The NHTS data involved travel information of 928 ridesharing users within 98 census tracts in San Diego. Two-level hierarchy (individual and census tract level) was constructed in the HNBGAM. In addition, the smooth function of the HNBGAM could help identify the nonlinear effects of ridesharing use frequencies on public transit usage. Demographic factors (age, gender, race, household size, etc.) and built environment factors (e.g., population density, worker density, percentage of rental houses, and house unit density) were also considered in the modeling process. The findings revealed a negligible impact on public transit usage for occasional ridesharing use (from one to eleven times per month), a complementary effect for regular ridesharing use (from eleven to thirty-two times per month), and a substitution effect for active ridesharing use (more than thirty-two times per month). Understanding such nonlinear relationships could help policymakers make more informed decisions to avoid the over-substitution of public transit usage and better complement the public transport system.

Association of Multiple Sclerosis Prevalence With Sociodemographic, Health Systems, and Lifestyle Factors on a National and Regional Level.

Multiple sclerosis (MS) prevalence varies widely by country and world region, variation that is often attributed to latitude and its association with vitamin D exposure. Given that increasing latitude is also associated with higher national wealth, this study investigated associations between MS prevalence and other factors driving regional differences, with a focus on sociodemographic, health systems, and lifestyle factors on a national and regional level. Using data from multilateral organizations and scientific literature, an ecological study was conducted to evaluate associations between age- and sex-adjusted MS prevalence and prespecified sociodemographic (gross domestic product [GDP] per capita and gross national income [GNI] per capita), health systems (current health expenditure per capita and by percentage of GDP, universal health coverage [UHC] index, and medical doctors per capita), neurology-specific (MRI unit density and neurologists per capita), and lifestyle (obesity and tobacco use) factors. National, regional, and income-stratified data were aggregated and employed in relevant univariable and multivariable regression models. Stepwise variable selection techniques identified independent predictors of MS prevalence. Univariable regression analyses showed significant associations at the national level for all investigated factors, except obesity prevalence and tobacco use. Latitude was significantly associated with MS prevalence in all world regions (β = 0.16-2.16), whereas the UHC index was significantly associated in 5 of 6 world regions (β = 0.18-3.17). MS prevalence was significantly associated with all factors except lifestyle factors and MRI unit density in high-income countries, but no associations were observed in low-income countries. Latitude was associated with MS prevalence for all income strata except low-income countries (β = 0.55-1.62). In multivariable analyses, current health expenditure per capita (β = 0.083, 95% CI 0.048-0.12, p < 0.01) and latitude (β = 1.05, 95% CI 0.63-1.47, p < 0.01) remained significantly associated with MS prevalence. Health expenditure per capita is strongly associated with national MS prevalence, suggesting that theories that attribute variations in MS prevalence primarily to latitude effects on vitamin D are incomplete. Health care access significantly contributes to the global variations in MS prevalence, especially since national wealth rises with latitude and likely results in significant underestimation of MS prevalence in countries with lower health expenditure.

The Polar Moment of Inertia of the Solid Mylar Balloon

Summary In this paper, we determine the polar moment of inertia IM of a solid Mylar balloon-shaped object with unit density by evaluating a triple integral in cylindrical coordinates. This integral is resolved in terms of the classical beta function. The same technique can be employed to determine all of its higher moments as well.

Quantum phases of dipolar bosons in one-dimensional optical lattices

We theoretically analyze the phase diagram of a quantum gas of bosons that interact via repulsive dipolar interactions. The bosons are tightly confined by an optical lattice in a quasi-one-dimensional geometry. In the single-band approximation, their dynamics is described by an extended Bose-Hubbard model where the relevant contributions of the dipolar interactions consist of density-density repulsion and correlated tunneling terms. We evaluate the phase diagram for unit density using numerical techniques based on the density-matrix renormalization group algorithm. Our results predict that correlated tunneling can significantly modify the parameter range of the topological insulator phase. At vanishing values of the onsite interactions, moreover, correlated tunneling promotes the onset of a phase with a large number of low-energy metastable configurations.

Associations between neighborhood built environment, residential property values, and adult BMI change: The Seattle Obesity Study III

ObjectiveTo examine associations between neighborhood built environment (BE) variables, residential property values, and longitudinal 1- and 2-year changes in body mass index (BMI). MethodsThe Seattle Obesity Study III was a prospective cohort study of adults with geocoded residential addresses, conducted in King, Pierce, and Yakima Counties in Washington State. Measured heights and weights were obtained at baseline (n = 879), year 1 (n = 727), and year 2 (n = 679). Tax parcel residential property values served as proxies for individual socioeconomic status. Residential unit and road intersection density were captured using Euclidean-based SmartMaps at 800 m buffers. Counts of supermarket (0 versus. 1+) and fast-food restaurant availability (0, 1–3, 4+) were measured using network based SmartMaps at 1600 m buffers. Density measures and residential property values were categorized into tertiles. Linear mixed-effects models tested whether baseline BE variables and property values were associated with differential changes in BMI at year 1 or year 2, adjusting for age, gender, race/ethnicity, education, home ownership, and county of residence. These associations were then tested for potential disparities by age group, gender, race/ethnicity, and education. ResultsRoad intersection density, access to food sources, and residential property values were inversely associated with BMI at baseline. At year 1, participants in the 3rd tertile of density metrics and with 4+ fast-food restaurants nearby showed less BMI gain compared to those in the 1st tertile or with 0 restaurants. At year 2, higher residential property values were predictive of lower BMI gain. There was evidence of differential associations by age group, gender, and education but not race/ethnicity. ConclusionInverse associations between BE metrics and residential property values at baseline demonstrated mixed associations with 1- and 2-year BMI change. More work is needed to understand how individual-level sociodemographic factors moderate associations between the BE, property values, and BMI change.

Predicting narrow ureters before ureteroscopic lithotripsy with a neural network: a retrospective bicenter study.

In some patients, the passage of semi-rigid ureteroscopes up the ureter is impossible due to narrow ureteral lumen. We established a neural network to predict the inability of the ureter to accommodate the semi-rigid ureteroscope and the need for active or passive dilatation using non-contrast computed tomography (CT) images. Data were collected retrospectively from two centers of 1989 eligible patients who underwent ureteroscopic lithotripsy with ureteral stones. Patients were categorized into two groups: control and narrow ureter. The network was designed and trained for predicting a narrow ureter during initial ureteroscopic lithotripsy, which integrated multi-scale features of the ureter. The predictive efficacy of neural networks DenseNet3D, ResNet3D, ResNet3D MC, and TimeSformer was compared. Furthermore, a previous ureteroscopy or a history of double-J stent placement, ureteral wall thickness and Hounsfield unit (HU) density of the ureter under the stone were compared. Model performance was assessed based on the accuracy, area under the receiver operating characteristic curve (AUC ROC), etc. The DenseNet3D-based network achieved an AUC ROC score of 0.884 and an accuracy of 85.29%, followed by the ResNet3D-based network, the ResNet3D MC-based network, and the TimeSformer-based network. The DenseNet3D-based network significantly outperformed other candidate predictors. Furthermore, the networks were validated in an external test set. Decision curve analysis showed the clinical utility of the neural network. The neural network provides an individualized preoperative prediction of narrow ureter based on non-contrast CT images, which could be employed as part of a surgical decision-making support system.

Clinical effects of autologous follicular unit extraction transplantation in the treatment of small area secondary cicatricial alopecia after burns

Objective: To explore the clinical effects of autologous follicular unit extraction (FUE) transplantation in the treatment of small area secondary cicatricial alopecia (hereinafter referred to as cicatricial alopecia) after burns. Methods: A retrospective observational study was carried out. According to the adopted treatment methods, 18 patients (12 males and 6 females, aged (29±6) years) who received autologous FUE transplantation for small area cicatricial alopecia after burns from March 2017 to November 2019 in the First Affiliated Hospital of Air Force Medical University were included in FUE transplantation group, and 18 patients (13 males and 5 females, aged (33±5) years) who were treated with expanded flap transplantation for small area cicatricial alopecia after burns by the same surgery team during the same period in the same hospital were included in expanded flap transplantation group. All the patients were followed up for more than 1 year. At the last follow-up, the follicular unit density in the transplanted area was measured by Folliscope hair detection system and the hair survival rate was calculated; the visual analogue scale (VAS) method was adopted to evaluate the treatment effect; patients were asked their satisfaction with the treatment effect and the occurrence of complications during follow-up; the hair growth and the scalp thickness, pain, pruritus, pigmentation, and surface roughness of the transplanted area were recorded. Data were statistically analyzed with Fisher's exact probability test and independent sample t test. Results: At the last follow-up, the follicular unit density in the transplanted area of patients in FUE transplantation group was (46.8±2.0)/cm2, which was significantly higher than (42.5±4.3)/cm2 in expanded flap transplantation group (t=3.84, P<0.01); the hair survival rates of patients were similar between the two groups (P>0.05). At the last follow-up, VAS scores evaluating the treatment effect of patients were similar between the two groups (P>0.05); the satisfaction score of patients toward the treatment effect in FUE transplantation group was 8.6±1.1, which was significantly higher than 7.6±0.8 in expanded flap transplantation group (t=2.89, P<0.01). During the follow-up, no inflammation or infection occurred in patients of the two groups, but only 2 patients in expanded flap transplantation group had postoperative pain. At the last follow-up, the transplanted area of patients in the two groups was covered with new hair, and the hair growth direction was basically consistent with the surrounding normal hair; scalp thickness, pain, pruritus, pigmentation, and surface roughness of the transplanted area of patients were similar between the two groups (P>0.05). Conclusions: Autologous FUE transplantation has better long-term follicular unit density and patients' satisfaction than expanded flap transplantation in the treatment of small area cicatricial alopecia after burns, showing better postoperative effect and a good prospect of clinical application.

The Emerald Tutu: Floating Vegetated Canopies for Coastal Wave Attenuation

Nature-based solutions (NBS) have been broadly defined in coastal resilience as the restoration of natural environments or as civil infrastructure with natural elements, with examples ranging from marsh restoration and new oyster beds to artificial reefs and living shorelines. The multiplicity of NBS types makes it difficult to quantify and model their effectiveness as a whole in coastal flood reduction and environmental co-benefits. Specific types of NBS operate under a variety of physical and ecological regimes: oyster beds care about the benthic environment and can be modeled as bed roughness elements, while living shorelines are a combination of emergent/submerged vegetation elements located in the dynamic swash zone. As such, NBS cannot be investigated as a monolith and their evaluation will be intervention-specific. Here, we present the evaluation of an engineered NBS called the Emerald Tutu, a series of interlinked vegetated mats which leverage known physical and ecological properties of marsh environments and combine them in networked formats for rapid deployment around shoreline environments. The Tutu takes inspiration from marsh canopies, but aims to transport the physical protection of these canopies to urban areas using the wave attenuation properties of floating vegetation elements and network effects. Prototype Tutu units were deployed in the OH Hinsdale Wave Lab at Oregon State University in summer 2021 to test the physical efficacy of the mat networks. The results show the effect of network arrangement, mat canopy size, and Tutu unit density on wave attenuation. We show how these results can be used to design the Tutu for a variety of coastal environments, and discuss the impact of submerged vegetation dynamics on Tutu effectiveness and what research gaps remain for the implementation of these kinds of engineered NBS.

Cerebral Vascular Density and Its Possible Correlation with Alzheimer Disease Progression in Elderly Individuals with Rheumatoid Arthritis

BackgroundRheumatoid Arthritis (RA) is characterized by chronic systemic inflammation, primarily affecting the joints. In RA patients, high concentrations of inflammatory cytokines are found within the synovial fluid and serum (PMID: 1700672). These cytokines reduce the blood brain barrier (BBB) integrity by decreasing the expression of tight junction proteins (PMID: 29910805). In a RA animal model such decreased BBB integrity has been shown to affect the transport of amyloid beta peptide (Aβ) between the peripheral circulation and the brain, thereby promoting accumulation of Aβ within the cerebral vasculature followed by the endothelial cell degeneration (PMID: 22029666). In humans, a similar pathologic process is a major risk factor for Alzheimer’s Disease (AD) which accelerates neuronal loss and cognitive impairment associated with AD (PMID: 29377008). Assessment of cerebral vascular density is an emerging modality for detection and monitoring the progression of cerebrovascular disease (CVD) (PMID: 15564412). Advancements in computed tomography (CT) imaging technology and the development of novel contrast agents should provide more accurate assessment for CVD in humans.The main objective of this study was to test high‐resolution CT imaging using a recently developed BriteVu contrast agent in conjunction with conventional histological techniques for postmortem assessment of CVD and pathology in the cerebral cortex and hippocampus of two male cadavers. The first, 74‐year‐old (D1) was diagnosed with RA and AD, while the second, 90‐year‐old (D2) had RA.ResultsThe D1 and D2 cadavers were fixed and perfused with BriteVu contrast agent. Heads were removed and scanned with a VimagoGT30 CT scanner at 300 µm. The images were subjected to volumetric analysis using Radiant software. The results showed that scans of the cerebral cortex from D2, specifically the middle frontal, inferior parietal, and superior temporal gyri, had significantly lower mean Hounsfield unit densities (MHUD) than those from the same regions of D1. The MHUD from the hippocampal scans revealed no significant difference. The lower MHUD count in the D2 cortex in comparison to D1 most likely reflects a lower vascular density in the respective brain region. The AD related pathology in both donors was assessed by histochemical and immunohistochemical techniques. To that end, the brains were extracted and fixed in formalin solution for 12‐16 weeks. The brain hippocampal and cortical sections were paraffin processed followed by H&amp;E and immunohistochemical staining for Aβ 1‐42, phospho‐tau, and phospho‐TDP‐43. Analysis of the data confirmed the AD diagnosis in D1 and demonstrated distinct AD pathology in D2. The AD staging could be characterized as mild in D1 and intermediate in D2.Conclusionsi) The vascular density within the cerebral cortex of elderly individuals with RA could correlate with the AD progression. ii) The adaptation of the reported CT imaging technique for its use in live individuals could provide more sensitive and accurate method for assessing AD in RA patients at the early AD stage(s).

Intellectual Structure and Emerging Trends of White Matter Hyperintensity Studies: A Bibliometric Analysis From 2012 to 2021.

White matter hyperintensities (WMHs), which have a significant effect on human health, have received increasing attention since their number of publications has increased in the past 10 years. We aimed to explore the intellectual structure, hotspots, and emerging trends of publications on WMHs using bibliometric analysis from 2012 to 2021. Publications on WMHs from 2012 to 2021 were retrieved from the Web of Science Core Collection. CiteSpace 5.8.R3, VOSviewer 1.6.17, and an online bibliometric analysis platform (Bibliometric. com) were used to quantitatively analyze the trends of publications from multiple perspectives. A total of 29,707 publications on WMHs were obtained, and the number of annual publications generally increased from 2012 to 2021. Neurology had the most publications on WMHs. The top country and institution were the United States and Harvard University, respectively. Massimo Filippi and Stephen M. Smith were the most productive and co-cited authors, respectively. Thematic concentrations primarily included cerebral small vessel disease, diffusion magnetic resonance imaging (dMRI), schizophrenia, Alzheimer’s disease, multiple sclerosis, microglia, and oligodendrocyte. The hotspots were clustered into five groups: white matter and diffusion tensor imaging, inflammation and demyelination, small vessel disease and cognitive impairment, MRI and multiple sclerosis, and Alzheimer’s disease. Emerging trends mainly include deep learning, machine learning, perivascular space, convolutional neural network, neurovascular unit, and neurite orientation dispersion and density imaging. This study presents an overview of publications on WMHs and provides insights into the intellectual structure of WMH studies. Our study provides information to help researchers and clinicians quickly and comprehensively understand the hotspots and emerging trends within WMH studies as well as providing direction for future basic and clinical studies on WMHs.

Mapping nectar-rich pollinator floral resources using airborne multispectral imagery

Wild pollinator numbers are known to be positively associated with amounts of flower-rich habitat at landscape level. Increasing floral resources can be particularly beneficial in relatively nectar-poor agricultural systems and having a baseline understanding of the temporal and spatial availability of resources can allow targeted habitat management. Very high-resolution remote sensing has potential to facilitate accurate mapping of fine-scale, within-habitat pollinator foraging resources, thereby allowing spatial and temporal gaps to be identified and addressed, improving predictions of pollinator numbers, and enabling remote monitoring of pollinator conservation measures.Concentrating on hedgerow and flower-rich field margins in a UK agricultural landscape, we showed that multispectral airborne imagery with 3 cm and 7 cm spatial resolutions can be used to classify five nectar-rich flowering plant species (Prunus spinosa, Crataegus monogyna, Rubus fruticosus, Silene dioica and Centaurea nigra) using a maximum likelihood classification algorithm. In 2019, we separately acquired 3 cm and 7 cm imagery for the months of March, May and July, respectively. Overall accuracies were above 90% for each month at both 3 cm and 7 cm resolutions (range 92.32%–98.72%), supporting previous research that suggests higher spatial resolutions do not necessarily lead to higher accuracies, as pixel variability is increased.Remaining challenges include determining which co-flowering species of similar colours in the visible range can be distinguished from one another within classifications and quantifying floral unit density from classifications so that the nectar sugar supply can be calculated. Nonetheless, we provided a prototype approach for mapping pollinator foraging resources in an agricultural context, which can be extended to other nectar-rich species. The foundation is set for developing a remote sensing pipeline that can provide valuable data on the availability of nectar-rich flowering plant species at different time-points throughout the year.

Automated Detection, Segmentation, and Classification of Pleural Effusion From Computed Tomography Scans Using Machine Learning.

ObjectiveThis study trained and evaluated algorithms to detect, segment, and classify simple and complex pleural effusions on computed tomography (CT) scans.Materials and MethodsFor detection and segmentation, we randomly selected 160 chest CT scans out of all consecutive patients (January 2016–January 2021, n = 2659) with reported pleural effusion. Effusions were manually segmented and a negative cohort of chest CTs from 160 patients without effusions was added. A deep convolutional neural network (nnU-Net) was trained and cross-validated (n = 224; 70%) for segmentation and tested on a separate subset (n = 96; 30%) with the same distribution of reported pleural complexity features as in the training cohort (eg, hyperdense fluid, gas, pleural thickening and loculation). On a separate consecutive cohort with a high prevalence of pleural complexity features (n = 335), a random forest model was implemented for classification of segmented effusions with Hounsfield unit thresholds, density distribution, and radiomics-based features as input. As performance measures, sensitivity, specificity, and area under the curves (AUCs) for detection/classifier evaluation (per-case level) and Dice coefficient and volume analysis for the segmentation task were used.ResultsSensitivity and specificity for detection of effusion were excellent at 0.99 and 0.98, respectively (n = 96; AUC, 0.996, test data). Segmentation was robust (median Dice, 0.89; median absolute volume difference, 13 mL), irrespective of size, complexity, or contrast phase. The sensitivity, specificity, and AUC for classification in simple versus complex effusions were 0.67, 0.75, and 0.77, respectively.ConclusionUsing a dataset with different degrees of complexity, a robust model was developed for the detection, segmentation, and classification of effusion subtypes. The algorithms are openly available at https://github.com/usb-radiology/pleuraleffusion.git.

Subtle side chain modification of triphenylamine‐based polymer hole‐transport layer materials produces efficient and stable inverted perovskite solar cells

AbstractPolymer hole‐transport layers (HTLs) are critical components of inverted perovskite solar cells (IPVSCs). Triphenylamine derivatives PTAA (poly[bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine]) and Poly‐TPD (poly[N,N′‐bis(4‐butylphenyl)‐N,N′‐bis(phenyl)benzidine]) have been widely adopted as hole‐transport materials due to their perovskite passivation effects and suitable energy levels. However, the passivation mechanism (i.e., the functional group responsible for perovskite passivation) of triphenylamine derivative polymers remains unclear, hindering the development and application of this polymer type. Here, we develop a novel Poly‐TPD derivative, S‐Poly‐TPD, by replacing the n‐butyl functional group of Poly‐TPD with an isobutyl group to explore the influence of alkyl groups on HTL performance and top‐deposited perovskite properties. Compared with Poly‐TPD, the increased CH3‐terminal unit density and the decreased spatial distance between the –CH–CH3 and –CH2–CH3 units and the benzene ring in S‐Poly‐TPD not only enhanced the hole‐transport ability but also improved the perovskite passivation effect, revealing for the first time the role of the alkyl groups in perovskite passivation. As a result, the S‐Poly‐TPD‐based IPVSCs demonstrated high power‐conversion efficiencies of 15.1% and 21.3% in wide‐bandgap [MAPbI2Br(SCN)0.12] and normal‐bandgap [(FAPbI3)0.92(MAPbBr3)0.08] devices, respectively.

Dispersant Effects on Single-Walled Carbon Nanotube Antibacterial Activity.

There is significant interest in understanding whether nanomaterials with outstanding mechanical or electrical properties also possess antibacterial properties. However, assessment of antibacterial activity is a complex problem at the interface of chemistry and microbiology. Results can be affected by many factors including nanomaterial size, surface chemistry, concentration, and the dispersion media. The difficulty of dispersing nanomaterials such as single-walled carbon nanotubes (SWNTs) has resulted in many studies being conducted in the presence of dispersion aides which may themselves contribute to bacterial stress. The recent discovery that a standard microbial growth media, tryptic soy broth (TSB), is an effective SWNT dispersant provides a new opportunity to investigate the potential antibacterial activity of SWNTs using dispersants that range from antibacterial to growth-supporting. The five dispersants chosen for this work were Sodium dodecyl sulfate (SDS), pluronic, lysozyme, DNA, and tryptic soy broth. Staphylococcus aureus and Salmonella enterica were used as the model Gram-positive and Gram-negative bacteria. Activity was measured in terms of colony forming unit (CFU) and optical density measurements. None of the systems exhibited activity against Salmonella. SDS was fatal to Staph. aureus regardless of the presence of SWNTs. The activity of pluronic and lysozyme against Staph. aureus was enhanced by the presence of SWNTs. In contrast, the DNA and TSB dispersions did not have any activity regardless of the presence of SWNTs. These results highlight that the purported antibacterial activity of SWNTs may only be effective against bacteria that are sensitized by the dispersant and suggests the need for additional research on the mechanisms by which SWNT-dispersant interactions can result in antibacterial activity.

The Relationship Between Renal Stones and Primary Aldosteronism.

IntroductionThe association between primary aldosteronism (PA) and nephrolithiasis is still unclear. The hypercalciuria and hypocitraturia of PA patients might be the reason leading to recurrent calcium nephrolithiasis. This study aimed to evaluate the relationship between PA and renal stones, including stone size and density.Materials and MethodsFrom February 2010 to March 2021, we retrospectively collected 610 patients who presented to our medical center with hypertension history, and all these patients, suspicious of PA, had PA data survey. In total, 147 patients had kidney stone and were divided into 44 patients with essential hypertension as group 1 and 103 patients with PA as group 2. Pearson χ2 test and independent Student’s t-test were performed to examine the differences among variables.ResultsThe mean age was 54.4 ± 12.0 years in group 1 and 53.0 ± 11.1 years in group 2. The incidence rate of renal stones in the PA group was around 24%. No significant differences between the two groups were found for gender, systolic/diastolic blood pressure, duration of hypertension, diabetes mellitus history, and laterality of kidney stone; however, mean stone size was 4.0 ± 3.3 mm in group 1 and 6.5 ± 7.2 mm in group 2, with a significantly larger renal stone size noted in the PA group than that in the essential hypertension group (p = 0.004). Hounsfield unit (HU) density was higher in the PA group vis-à-vis the essential hypertension cohort, although this did not reach a significant difference (p = 0.204).ConclusionsOur study revealed that PA patients had a higher incidence rate of renal stones compared to that of the general population. Besides, the PA-related renal stones also presented as larger and harder than those of the essential hypertension group. Further investigation concerning the association between PA and renal stones is warranted.

Effect of Degradation of Municipal Solid Waste On the Shear Strength Behavior from a Dump Site In Una Town, Himachal Pradesh

The behavior of shear strength property of municipal solid waste (MSW) during decomposition/degradation was presented in this study. The large-scale direct shear laboratory tests were performed for analyzing the variation in shear properties of fresh to decomposed waste. The physical characteristics, organic content, moisture content at different stages of degradation and increasing age were evaluated for better understanding of the mechanical response. The reduction in the organic fraction from 56% to 16.5% was observed with increase in depth. However, the unit weight increased with the degradation from 6.97 kN/m3 for fresh to 7.05-10.3 kN/m3 for degraded waste. The results obtained from the direct shear test indicated an increase in the angle of internal friction (φ) whereas cohesion (c) did not follow any pattern with degradation of waste. It was further observed that the fresh samples of MSW exhibited lower strength than degraded waste. The shear strength of waste was observed to increase with rise in finer fraction thereby also increasing the unit weight and density of the waste. The mobilized cohesion of waste was observed to vary from 31.9 kPa to 33.4 kPa with an increase in depth till 1.5 m. The results obtained from the tests were compared with the literature and the best fit shear strength parameters for the current study depending upon the degradation of waste was characterized by cohesion value 32.6 kPa and angle of internal friction of 21°.

Effect of Temperature on Densification Pressure and the Unit Density in Production of Corn Straw Pellet with a Post-Heating Method

In the biomass densification process, a lot of energy is needed to prevent its spring-back and to overcome the friction between the material and the channel surface of the die so as to build up pressure. However, moisture, particle size, temperature, and type of material all influence the densification pressure, pellet quality, and the density. The research was aimed to find out how the densification pressure and density were affected by the die temperature based on an open-end densification method using a self-developed pellet extruder. When the piston fixed in the front of the extruder moved in a reciprocating way, the raw material was pressed into the opening die, which had a heater wrapped up. Crushed corn straw with a particle size under 4 mm and with a given moisture content of 10% was used to be compacted by the extruder. The results showed that with the increase of the die temperature, the value of densification pressure decreased; however, the quality of pellets was not good at temperatures higher than 140 °C. The proper temperature for corn straw densification was 100 °C, and the value of the unit density was above 1.0 g/cm³. Meanwhile, the surface quality of the pellet was comparatively good. The reference values of the friction coefficient at different temperatures were provided.

Analysis of feed pelleting characteristics based on a single pellet press device

Pelleting is the most extensively used thermal processing method in feed industry. In this article, a single pellet press device was developed to investigate the pelleting processing of animal feed. Effects of moisture content (10%-18% w.b.), preheating temperature (60°C-100°C) and maximum compression force (0.2-0.6 kN) on feed pellet were determined and analyzed, as well as energy consumption. The results showed that unit density, pellet hardness and energy consumption were 0.87-2.92 g/cm3, 1.08-4.55 kg, and 3.27-12.66 J/g, respectively. Unit density was found to increase with the increase of preheating temperature and maximum compression force, but decrease with the increase of moisture content. Pellet hardness showed a first ascending then descending trend with the increase of moisture content, but exhibited a positive relationship with both preheating temperature and maximum compression force. Energy consumption increased with the increase of maximum compression force, but exhibited descending trends with the increase of moisture content and preheating temperature. Due to its features of low cost, high efficiency and easy control, the single pellet press device has a wide application prospect in feed processing. Keywords: feed, pelleting, energy consumption, preheating temperature, experiments DOI: 10.25165/j.ijabe.20221504.6155 Citation: Peng F, Xiang R, Fang F, Liu D. Analysis of feed pelleting characteristics based on a single pellet press device. Int J Agric & Biol Eng, 2022; 15(4): 65–70.