Jammed elastic shells - a 3D experimental soft frictionless granular system.

Background:Respiratory and enteric infections remain a high burden worldwide. The spread of these infections is driven by person-to-person interactions, or ‘contacts’. Contact diaries have been widely used to collect information such as the number of contacts a person has throughout the day, and characteristics of each interaction that may be relevant for disease transmission. Wearable proximity sensors have been used to complement data from contact diaries, and in particular to capture contacts among children who are not able to report their contacts. Studies that have compared contact diary and wearable proximity sensors are mostly in high-income countries or conducted in small populations in low- and middle-income countries (LMICs). We aimed to compare how effectively the two methods capture contacts relevant for disease transmission in LMICs’ household settings.Methods:We conducted a population-based study and collected social contact data with contact diary and wearable proximity sensor in four LMICs – Guatemala, India, Mozambique, and Pakistan. We compared the number, concordance, and duration of contacts captured by the sensors and the reported in the contact diaries.Results:421 participants documented a total of 1189 unique contacts on contact diaries, and recorded 1248 unique sensor contacts. The mean number of unique contacts was higher in the contact diary than recorded by the sensors in India, lower in the contact diary than recorded by the sensors in Mozambique and Pakistan, and similar in Guatemala. In all countries, more than half of contact pairs were reported by both contact diary and sensors, though this varied by site with 56% of contact pairs reported by both methods in Mozambique and 87% of contact pairs in India. The duration of contacts reported by concordant contact pairs was longer in contact diary compared to the duration captured by sensors in all four countries.Conclusions:This study demonstrated that both contact diaries and wearable proximity sensors have unique features in measuring social contacts in LMICs, suggesting that they are complementary. Future work should consider the characteristics of each method in understanding person-to-person interactions relevant for infectious disease transmission and implement suitable options for the scope of their study.

The 3D Pelvic Inclination Correction System (PICS): A universally applicable coordinate system for isovolumetric imaging measurements, tested in women with pelvic organ prolapse (POP)

Radiological evaluation of inferior alveolar nerve displacement after removal of impacted mandibular third molars prior to sagittal split osteotomy

Objective: Brackets are orthodontic attachments bonded to a tooth for the purpose of securing an orthodontic archwire. The aim of this study was to evaluate whether human error affects bracket position errors by comparing digital and analogue indirect bonding (IDB) techniques with fully digitized IDB protocols. Methods: Thirty-six intraoral models were divided into three groups. Ten brackets were placed in each cast (incisors, canines, and premolars). In the automatic control group, brackets were placed according to facial axis point automatically calculated by Ortho Analyzer software. In the manual digital group (MDG) brackets were placed by an operator, while in the manual analogue group (MAG) brackets were placed on plaster models. Models were digitally superimposed and compared with control models (3D slicer). The linear and angular measurements were analyzed with Mann-Whitney U test and Chi-square test. Results: There were statistically significant differences in vertical, tipping, torque, and rotation for incisors and in vertical and torque for canines when comparing MDG with MAG placement. The error frequencies showed that 81.1% of brackets in the MDG were within acceptable limits, whereas only 62.5% were acceptable in the MAG group. The prevalence of accuracy in MDG was higher in all variables except tipping. Conclusion: Digital aids improved bracket position accuracy. Horizontal axis was the safest variable. Incisor of MAG showed increased discrepancy in all angular values and vertical dimension. Special consideration should be given to canines regarding vertical axis and torque errors in MAG. Angular positioning of premolars was more critical than linear positioning.

To observe the microstructure and cellular populations of normal human limbal and central corneas using laser confocal microscope. The study was consisted of 28 eyes of 15 examiners (age distribution, 16-61 years). After examinations with slit lamp biomicroscopy and ophthalmoscope, the images of superior, inferior limbus and central cornea were acquired by laser confocal microscope. Corneal microstructure and cell morphology were analyzed, and cell densities were measured. Lateral (x, y axis) and axial (z axis) images of limbal and central cornea were clear and vivid. Limbal palisades of Vogt were visible at the superior and inferior limbus. The red blood cells in the vessel of limbus were visible. The arrangement of surface epitheliums was rather loose, with bright borders and dark cell bodies. The surface epithelial cell density was (812 +/- 297) cells/mm(2) at the superior limbus and (785 +/- 263) cells/mm(2) at the inferior limbus. There was no statistical difference between the two group (P > 0.05). The bright and dendriform Langerhans cells were readily visible just under the epithelial cells. The Langerhans cell density was (288 +/- 102) cells/mm(2) at the superior limbus and (254 +/- 127) cells/mm(2) at the inferior limbus. There was no statistical difference between the two group (P > 0.05). At central cornea, the surface epithelial cells were loose, the borders of the cell were clear and bright, and the cell bodies were dark. The cell density was (1098 +/- 315) cells/mm(2), there were more cells in central cornea than other area of superior and inferior limbus (P < 0.05). The arrangement of basal epithelial cells was tight. Nerve plexus at subepithelium and anterior stroma were prominent with strong brightness. Langerhans cells were occasionally visible, and cell density cannot be measured. Subepithelial nerve fibers were thin with high tortuosity and a lot of branches, and deeper ones were thick with low tortuosity and few branch. In the stroma, separated keratocytes were visible under dark background, the boundaries were vague, the nucleis were bright and spindly. Hexagonal endothelial cells were arranged in order with light cell bodies and dark borders. The thickness of whole cornea, stroma or epithelium was (543.0 +/- 62.9), (462.0 +/- 69.5), (59.9 +/- 11.2) microm respectively. Laser confocal microscopy provides non-invasive, real-time, in vivo images of limbal and central corneas characterized with refined image definition, exact depth localization. It is valuable for basic research and clinical diagnosis of corneal disease.

The linear and non-linear rheology of a high volume fraction particle filled unentangledpolymer melt is measured. The particles in the polymer melt behave like hard spheres asthe particle volume fraction is raised. At high volume fractions, the suspension develops aplateau elastic modulus. Over the frequency range of the elastic modulus plateau, theviscous modulus develops a minimum and a maximum. The frequencies of the two localextrema initially have critical power law scaling, suggesting the approach of a singular glasstransition. At higher volume fractions in excess of the glass transition, the viscous moduluscontinues to show a well defined minimum and a well defined maximum. The non-linearmoduli show a single perturbative yield point beyond which the suspension softens. Theyielding behavior of the nanocomposite is shown to be sensitive to the strainfrequency and the proximity of the strain frequency to the maximum frequencyfor the linear viscous modulus from linear rheology which characterizes thermalrelaxation of glassy particle clusters in the zero strain limit. The linear and non-linearmeasurements are compared against a recently developed mechanical theory for colloidalglasses.

Magnesium composites with hybrid nano-reinforcements: 3D simulation of dynamic tensile response at elevated temperatures

Platelet-Rich Blood Clots

Finite element modeling of thermal conduction in spherical Al2O3 based composite materials

Investigating The Network Structure Of Type I Collagen As A Function Of Temperature And Concentration Via Confocal Microscopy

Numerical analysis of radiative transfer and prediction of spectral properties for combined material composed of nickel foam and TiO2 nanofluid

Relationship between polysialylated neural cell adhesion molecule and β-endorphin- or gonadotropin releasing hormone-containing neurons during activation of the gonadotrope axis in short daylength in the ewe

PurposeThe paper aims to study the variation of electrical properties like electrical resistivity and current noise of a polymer thick film resistor, namely, PVC‐graphite thick film resistor, with parameters such as volume fraction, grain size, temperature and high voltage.Design/methodology/approachA model is proposed to explain the observed variations, which assumes that the texture of the polymer thick film resistor consists of insulator granules coated with conducting particles and also having cavities. The resistivity of these resistors is controlled mainly by the contact resistance between the conducting particles and the number of contacts each particle with its neighbors.FindingsThe variation of resistivity with temperature and high voltage is explained with the help of the model and it is attributed to the change in contact area and number of contacts. The current noise of these resistors is controlled mainly by the average relative resistance fluctuations between the conducting particles and the number of contacts each particle with its neighbors.Originality/valueThe variation of current noise with high voltage has also been explained with the help of this model and it is attributed to the change in number of conducting particles and conducting layers.

Liquid-phase sintering experiments were performed and the number of contacts per grain, the dihedral angle, and the volume fraction of solid were measured in the settled solid-liquid. For the W-Ni-Fe case, Kipphut et al. observed a liquid top layer for a 78 wt pct W alloy. However, 78 wt pct W provides a volume fraction high enough to initiate tungsten particle contacts in the presintered condition which violates the free settling concept. Initial experiments were performed using 60 wt pct W compositions with various Ni-Fe-Cu compositions for the matrix phase

Evolution for the dynamic recrystallization (DRX) volume fraction of Ti-5Al-5Mo-5V-3Cr-1Zr near β titanium alloy during hot deformation was characterized by using the Johnson–Mehl–Avrami–Kolmogorov (JMAK) equation. To determine the equation parameters, a series of thermal simulation experiments at the temperature of 1023–1098 K and strain rate of 0.001–1 s‒1 to the true strain of 0.7 were conducted to obtain the essential data about stress σ and strain ε. By further transforming the relationship of σ versus ε into the relationship of strain hardening rate dσ/dε versus σ, two characteristic strains at the beginning of DRX (critical strain εc) and at the peak stress (peak strain εp) were identified from the dσ/dε-σ curves. Sequentially, the parameters in the JMAK equation were determined from the linear fitting of the different relationships among critical strain εc, peak strain εp and deformation conditions (including temperature T, strain rate $\dot \varepsilon $ and strain ε). The as-obtained JMAK equation was expressed as XDRX=1-exp[-0.0053((ε-εc)/εc)2.1], where εc=0.6053εp and εp=0.0031$\dot \varepsilon $0.0081exp(28,781/RT). Finally, the JMAK equation was implanted into finite element program to simulate the hot compression of thermal simulation experiments. The simulation predictions and experimental results about the DRX volume fraction distribution showed a good consistency.