Distribution Of Branches Research Articles

Fractal Analysis of Lung Structure in Chronic Obstructive Pulmonary Disease.

Chest CT is often used for localizing and quantitating pathologies associated with chronic obstructive pulmonary disease (COPD). While simple measurements of areas and volumes of emphysema and airway structure are common, these methods do not capture the structural complexity of the COPD lung. Since the concept of fractals has been successfully applied to evaluate complexity of the lung, this review is aimed at describing the fractal properties of airway disease, emphysema, and vascular abnormalities in COPD. An object forms a fractal if it exhibits the property of self-similarity at different length scales of evaluations. This fractal property is governed by power-law functions characterized by the fractal dimension (FD). Power-laws can also manifest in other statistical descriptors of structure such as the size distribution of emphysema clusters characterized by the power-law exponent D. Although D is not the same as FD of emphysematous clusters, it is a useful index to characterize the spatial pattern of disease progression and predict clinical outcomes in patients with COPD. The FD of the airway tree shape and the D of the size distribution of airway branches have been proposed indexes of structural assessment and clinical predictions. Simulations are also useful to understand the mechanism of disease progression. Therefore, the power-law and fractal analysis of the parenchyma and airways, especially when combined with computer simulations, could lead to a better understanding of the structural alterations during the progression of COPD and help identify subjects at a high risk of severe COPD.

The alterations of critical pore water pressure and micro-cracking morphology with near-wellbore fractures in hydraulic fracturing of shale reservoirs

The crack initiation and propagation in a laminated shale formation have been widely investigated, but the alterations of critical pore water pressure (including fracture initiation pressure and breakdown pressure) and the micro-cracking morphology with near-wellbore fracture geometry are still unclear. This paper numerically investigates the alterations of critical pore water pressure and the morphology of the hydraulic fractures in shale formation with different near-wellbore fractures. First, a hydro-fracturing model is developed for a laminated shale formation within the framework of PFC2D. Then, this model is validated with the Blanton’s criterion, pressure history and fracture geometry. Finally, the effects of length, shape, and symmetry properties of near-wellbore fractures on the critical pore water pressure and micro-cracking morphology are comparatively investigated. The critical pore water pressure, micro-cracking morphology, aperture and permeability, and the fractal dimension of hydraulic fractures are quantitatively analyzed at three initial near-wellbore fractures. Simulation results indicate that the length and the distribution of near-wellbore fracture branches play a crucial role in pore water pressure variation and micro-crack propagation during hydraulic fracturing. The critical pore water pressure is sensitive to the initial near-wellbore fracture length especially when the initial fracture length exceeds a critical fracture length. The shape of initial near-wellbore fracture could change the distribution of micro cracks and induce large pore water pressure. The symmetrical radial fracture (θ=0°) more likely causes a hydraulic fracture with high permeability while the X-shape fracture (θ=30°) contributes greatly to the complexity of the fracture network and stimulated reservoir volume. These findings on the pore water pressure variation and the micro-cracking morphology are helpful in the optimization design of hydraulic fracturing treatment.

Influence of Metal-Alkyls on Early-Stage Ethylene Polymerization over a Cr/SiO2 Phillips Catalyst: A Bulk Characterization and X-ray Chemical Imaging Study.

The Cr/SiO2 Phillips catalyst has taken a central role in ethylene polymerization since its invention in 1953. The uniqueness of this catalyst is related to its ability to produce broad molecular weight distribution (MWD) PE materials as well as that no co‐catalysts are required to attain activity. Nonetheless, co‐catalysts in the form of metal‐alkyls can be added for scavenging poisons, enhancing catalyst activity, reducing the induction period, and tailoring polymer characteristics. The activation mechanism and related polymerization mechanism remain elusive, despite extensive industrial and academic research. Here, we show that by varying the type and amount of metal‐alkyl co‐catalyst, we can tailor polymer properties around a single Cr/SiO2 Phillips catalyst formulation. Furthermore, we show that these different polymer properties exist in the early stages of polymerization. We have used conventional polymer characterization techniques, such as size exclusion chromatography (SEC) and 13C NMR, for studying the metal‐alkyl co‐catalyst effect on short‐chain branching (SCB), long‐chain branching (LCB) and molecular weight distribution (MWD) at the bulk scale. In addition, scanning transmission X‐ray microscopy (STXM) was used as a synchrotron technique to study the PE formation in the early stages: allowing us to investigate the produced type of early‐stage PE within one particle cross‐section with high energy resolution and nanometer scale spatial resolution.

Anatomical Study of the Innervation of the Masseter Muscle and Its Correlation with Myofascial Trigger Points.

Background and PurposeMyofascial pain syndrome (MPS) is widely prevalent in the general population; some reports estimate its prevalence ranges from 9 to 85%. Among the different locations where MPS may arise, pain related to the masseter muscle is referred as masticatory myofascial pain. MPS is characterized by myofascial trigger points (MTPs), which represent tender anatomical areas of a muscle where painful symptoms are elicited whenever stimulated. Previous publications have found MTPs to coincide with neuromuscular junctions at the motor end plate, at the innervation zone (IZ). Our study aimed to describe the innervation of the masseter muscle and relate it to clinically described myofascial trigger points (MTPs).Materials and MethodsWe mapped the nerve fiber distribution into the masseter muscles from 16 cadavers by anatomical dissection. We divided the muscle into six regions, three superior (I–III) and three inferior (IV–VI), and classified the nerve’s branches distribution according to these predetermined areas. Statistical analyses was made by Poisson distribution and logarithm link function followed by Bonferroni multiple comparisons (P<0.05).ResultsAll six areas received branches from the masseteric nerve. Areas I and II (upper posterior and upper intermediate, respectively) had a significant higher number of nerve entries as compared to the remaining areas.ConclusionThe penetration areas of the masseteric nerve have been established and MTPs are found in the innervation zones, clinicians should focus initially on the regions of the penetration points, for diagnostics and therapeutic measures, such as injections, dry needling and soft tissue interventions. Anatomical study of nerve supply to the masseter muscle can provide useful additional knowledge to further understanding masticatory myofascial pain and to direct therapeutic interventions and diagnostic studies of temporomandibular junction dysfunction.

Analysis of the mylohyoid nerve in elderly Japanese cadavers for dental implant surgery.

ObjectivesInjury to the mandibular nerve (MN) branches may cause pain and irregular occlusal movement during mastication after mandibular dental treatments. Growing evidence indicates that the calcitonin gene‐related peptide (CGRP) plays a key role in the development of peripheral sensitization and the associated enhanced pain, suggesting it may be a sign to ensure a safe and reliable dental implant treatment. Our focus was on the distribution of the MN branches and their communication with the lingual nerve (LN), the localized expression of CGRP, and the identification of a pain area related to the mylohyoid muscle (MM) fascia in the mandibular floor.Material and MethodsIn this study, MM samples from 440 sides of 303 human cadavers aged 61–103 years were examined microscopically and immunohistochemically. These data were further evaluated by the use of principal component analysis.ResultsA complex but weak attachment site was identified for the fascia of the MM. CGRP expression was mainly located in small vessels and was scattered throughout the whole fascia of the MM. Communication between the MN and LN was found in 62.5% (275/440) of the samples. The results from the principal component analysis showed that the positive contributions were from the descending branch in the premolar region (correlation coefficient value R = 0.665), the ascending branch in the molar region (R = 0.709) and the intermediate branch of the digastric branch (R = 0.720) in component 1. In the fascia off the MM, strongly labeled CGRP‐positive cells were also found around the blood vessels and the nerve.ConclusionsThe findings reported in this study indicate that there is a risk of damage when pulling the fascia off the MM at the border of the molar and premolar regions during dental implant surgery.

Fractionation of chain walking polyethylene and elucidation of branching, conformation and molar mass distributions

State-of-the-art liquid interaction chromatography (IC) allows separation of macromolecules according to chemical composition (CC), functionality or molecular topology in contrast to size-based approaches such as size exclusion chromatography (SEC), which has its limitations in distinguishing chemical structures. Yet, for macromolecules with multivariate molecular distributions, online identification and characterization of distinct components in bulk samples is a considerable challenge. A useful approach to narrow down the complexity of a given sample is preparative molar mass fractionation (pMMF) that provides fractions in mg or g scale, which can be subjected to further advanced analysis to elucidate the physical and structural properties of the sample. In this study, novel chain-walking polyethylenes (CWPE), which differ substantially in macromolecular architecture, are fractionated using pMMF. Using IC in temperature and solvent gradient modes (TGIC, SGIC), the pMMF fractions are separated according to branching topology. Quadruple-detector high temperature SEC is carried out to determine the physical properties and study the MM-dependent structural transformation of CWPE. A detailed branching analysis was carried out by means of nuclear magnetic resonance. Two-dimensional liquid chromatography (LC) hyphenating IC and SEC provides comprehensive bivariate correlations between MM and molecular topology.

Tipos de condução do maracujazeiro amarelo e suas influências sobre as características produtivas

O maracujazeiro possui crescimento contínuo e indeterminado, necessitando de condução para melhor distribuição dos ramos nas estruturas de sustentação. O objetivo deste trabalho foi avaliar a biometria e os parâmetros produtivos do maracujazeiro amarelo (Passiflora edulis Sims) enxertado em resposta a diferentes tipos de condução dos ramos secundários. O experimento foi instalado e conduzido no município de Pracinha, SP, no período de maio de 2016 a abril de 2017, utilizando-se o delineamento experimental em blocos ao acaso, com quatro tratamentos e seis repetições. Os tratamentos constituíram-se dos seguintes tipos de condução dos ramos secundários: T1 – poda do ramo principal conduzindo um ramo secundário lateral; T2 – poda do ramo principal conduzindo dois ramos secundários laterais; T3 – ramo principal dobrado conduzindo um ramo secundário lateral; T4 – ramo principal dobrado conduzindo dois ramos secundários laterais. Avaliaram-se o comprimento dos ramos secundários, o número de ramos terciários, o comprimento, diâmetro e massa dos frutos, o número de frutos por planta e a produtividade. Não houve diferenças significativas para número de ramos terciários, comprimento, diâmetro e massa de frutos. Verificou-se que o número de frutos por planta e a produtividade do maracujazeiro amarelo são influenciados pelo tipo de condução dos ramos secundários que não altera as características físicas dos frutos. Dobrar o ramo principal conduzindo dois ramos laterais favorecem o desenvolvimento e a produção do maracujazeiro-amarelo.

Spatiotemporal distribution of canopy litter and nutrient resorption in a chronosequence of different development stages of Cunninghamia lanceolata in southeast China

Canopy litter is an important component of coarse woody debris (CWD), which affects nutrient and carbon cycling in forest ecosystems. For marcescent plant species (characterized by dead branches and leaves remaining in the canopy for several years before abscission), nutrient resorption from senescing leaves is an important nutrient conservation strategy. However, investigating the ecological function of canopy litter is challenging due to its limited accessibility and also the heterogeneous canopy microclimate in terms of light transmission, temperature and moisture. We studied the spatiotemporal distribution of canopy litter mass and seasonal dynamics of leaf nutrients and nutrient resorption during senescence in the canopy along a chronosequence of Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] plantations in southeast China. The dry mass weight of dead branches and dead leaves in the canopy significantly increased with stand stage (14.6, 14.2, and 17.4 t ha−1 for young, middle-aged, and mature stands respectively), accounting for high proportions of total aboveground litter of 85.7%, 79.1% and 80.0%, respectively, along with annual litterfall production (2.44, 3.75, and 4.34 t ha−1, respectively). The canopy height distribution of dead branches and leaves also increased with stand age, ranging from 0 to 4 m in young stands, 3–8 m in middle-aged stands, to 4–10 m in mature stands. The seasonal pattern of canopy litter mass was the inverse of litterfall production: canopy litter mass peaked, while litterfall production was lowest in winter. Mean N, P, K, and Mg nutrient resorption efficiencies across stands at each stage were 53.8–58.9%, 64.0–68.9%, 85.0–90.2%, and 46.5–56.6%, respectively, while Ca was not retranslocated from senescing leaves. In summary, Chinese fir plantations retain large amounts of dead branches and leaves in the canopy from which at least ~50% of the nutrients N, P, K and Mg are recycled, representing an important nutrient conservation strategy that has evolved to adapt to nutrient-limited habitats. Canopy litter therefore plays an important role in these forest plantation ecosystems and should be protected instead of being removed from the canopy to the forest floor.

Trends of Graduate Theses with the Subject of Education and Training Conducted on Creativity

The aim of this research is to examine the trends of the studies that address the education-training dimension of creativity in Turkey. The research was conducted using a qualitative research pattern. The data was collected and analyzed through document analysis. In the analysis of the data, the thesis analysis form developed by the researchers was used. One hundred and forty-five graduate theses studied between 2005 and 2019 in the field of education, which were allowed access by their authors, constitute the study group of this research. 114 of these works consist of graduate theses and 31 of them consist of doctoral theses. The graduate theses in the Council of Higher Education database were examined under a total of 10 titles according to their distribution over the years-educational levels, university distributions, institute distributions, branch distributions, methods and sub-methods, data collection tools, sampling/study groups, sampling methods, education level of the study group and thesis titles. As a result of the research, it was observed that although studies addressing the educational-educational dimension of creativity have increased at a certain level over the years, they are not at the desired point and have not been studied adequately. In addition, it was determined that the studies carried out in terms of the discipline, the methods used and the variety of topics studied had similarities, that no studies on creativity were conducted in some departments, that the study group usually consists of a single level of education, that this situation does not allow to look at creativity from a broad perspective, and that there are many aspects of creativity that have not been studied for those who will work in the educational dimension.

Variations in patterns of internode and branch lengths for several bamboo species

Bamboos are an important plant resource both economically and ecologically and it is, therefore, important to fully understand their biosystem characteristics. In this study, the variations in patterns of internode and branch lengths for twelve bamboo species were examined. The results indicated that node distribution along the culm is not always dense near the ends of the culm and sparse in the middle part of the culm. There were variations in the position of maximum internode length among the 12 bamboo species. For most bamboo species, maximum internode lengths correlated with total culm heights. Similar relationships existed between log (node number) and log (accumulated internode length) at the individual and species levels, and these relationships can be fitted by a linear or sigmoid function of the third-order function. Scaling exponents changed gradually during internode growth for individuals. The relationships between log (average of internode length) and log (variance of internode length) were complicated between individuals and species. The frequency distribution of bamboo branches followed power laws, but the exponents varied with species and individuals. The results may provide a new understanding of the optimal design in the unique biosystem of bamboos.

The Anatomy of the Temporal and Zygomatic Branches of the Facial Nerve: Application to Crow's Feet Wrinkles.

Advances in the understanding of wrinkling crow's feet while improving the safety and efficacy of botulinum toxin type A injection has pointed to drug dispersion in the lateral orbital wrinkles as a cause of adverse events of botulinum toxin type A injection. The purpose of this study is to identify the distribution of temporal and zygomatic branches of facial nerve in the orbicularis oculi muscles. Anatomical dissection of cadavers was performed in 31 cadavers, 13 females and 18 males, with ages ranging from 20 to 60 years, which of all had been embalmed by 10% formalin solution. The facial nerve was identified within subcutaneous tissue close periorbital region and both traced proximal and distal. Its temporal branch, zygomatic branch, facial and muscular entrance were located and accurately measured relative to established surface landmarks. Dissection of the facial nerve revealed 2 to 6 entrances of the temporal branch into the orbicularis oculi and 1 to 5 entrances of the zygomatic branch into the orbicularis oculi. Concerning the measurements of neural entering points, distance and angle from orbicularis oculi muscle to lateral ocular angle, a distribution map of its muscular entrance and their patterns of distribution were constructed. According to the dense area of the coordinate map, there were 3 points determined as the muscular entrance points to established surface landmarks. An anatomical dissection of cadavers was performed to identify the distribution of temporal and zygomatic branches of the facial nerve in the orbicularis oculi. According to the dense area of the coordinate map, the surface landmarks of 3 points were established as the muscular entrance of the facial nerve (MEF).

The geography of banking: Evidence from branch closings

AbstractIn the aftermath of the Great Recession, the number of bank branches declined in most developed countries. In this paper, we investigate how banks have downsized their branch networks in Italy, by comparing the pre‐ and post‐crisis spatial distribution of branches. By using a detailed data set that includes a wide set of controls for the characteristics of each bank branch, we estimate the probability of a branch being closed as a function of its distance from both proprietary and competitors' branches. We find that banks are more prone to close branches in those areas where other proprietary branches are closer and where competitors' branches are closer. This indicates that, since the start of the crisis, banks have closed branches especially in those areas where their proprietary network was relatively more populated and the competition was fiercer.

Study of pollution transport through the river confluences by derivation of an analytical model.

Due to the entrance of pollutants in different branches of the river network, it is essential to study contaminant transport at the river confluences. In the present study, it was attempted to investigate the conservative pollution transport at channel confluence by operating a series of experiments in the laboratory flume. In the designed laboratory model, two branches, with different widths of 45, 25 cm, were intersected and a channel confluence was created. Five entrance discharges and three initial contaminant concentrations, introduced using a linear feeder, were chosen as experimental variables. Conservative tracer of sodium chloride solution was used, and the electrical conductivities were measured at eight locations of the main channel and upstream branches with 2 seconds interval. Junction zone was assumed as a control volume, and by applying mass equilibrium to it, a new mathematical model was extracted. It was observed that there is concentration fluctuation in the falling limbs of the experimental breakthrough curves of the junction zone; however, it was diminished by downstream motion. Moreover, the observed pollution graphs had double peak points which changed to a single point with an increase of distance from the confluence position. Operation of the presented model was investigated by variation of its parameters. It was found that the contaminant residence time parameters of the confluence zone have the most significant influence in the simulation of the analytical model. Additionally, it was observed that the values of Gaussian distribution of the upstream branches could displace the position of pulses of resultant breakthrough curves or can overlap them. Moreover, the model performance was examined using statistical goodness of fit parameters like Nash-Sutcliffe, R2, and mean absolute error (MAE). Their values were calculated as 0.88, 0.91, 66.88 (ppm), respectively.

Preparation of branched polystyrene via atom transfer radical polymerisation using diene with electron-rich double bond

ABSTRACT Self-designed bis(4-vinylbenzyl)-oxalate (DBE) was synthesized successfully. The branched polystyrene was prepared by using an atom transfer radical polymerization method with copper bromide (CuBr)/2,2'-bipyridine (Bpy) as a catalyst, the DBE as a branched monomer and tert-butyl α-bromoisobutyrate (t-BBiB) as an initiator. The structure of the synthesized branched monomer was determined by nuclear magnetic resonance (NMR) spectroscopy. The conversion of monomer during the polymerization was measured by gas chromatography (GC) while the molecular weight, molecular weight distribution and degree of branching of the polystyrene were characterized by three-detection volume exclusion chromatography (TD-SEC). The results show that bis(4-vinylbenzyl)-oxalate with electron-rich double bond and styrene with electron-rich double bond can be successfully obtained branched polystyrene. The branched structure developed as the reaction proceeded. At the same time, the molecular weight of the branched polystyrene gradually increased as the reaction progressed, and the molecular weight distribution widened consistent with the increased degree of branching.

A unique case of brachial plexus form lateral to the axillary artery: a case report

Anatomical variations of the formation and distribution of the brachial plexus are fairly common and it is related to the embryological development of upper limbs. The present report describes an unusual variation of the brachial plexus in which the cords are arranged lateral to the 1st and 2nd parts of the axillary artery. Therefore, some of the main terminal branches show different relationship to the 3rd part of the axillary artery and the brachial artery. Awareness of such variations of the formation, relations and distribution of main branches of brachial plexus is of remarkable clinical importance for clinicians who carry out surgical, interventional radiological and anaesthetic procedures in the axillary region.

Long-term mechanical performance of polyethylene pipe materials in presence of carbon black masterbatch with different carriers

In this paper, two types of carbon black (CB) masterbatch with different carriers, i.e. HDPE and LDPE, are used to produce black compounds using three PE100 resins with various short chain branching distributions. Due to difference in short chain branch (SCB) distribution, the used polyethylene resins behave differently in microstructure development and long-term creep behavior. The microstructural analysis using different DSC techniques and rheological measurements revealed more sensitivity of the polyethylene resin with uniform comonomer distribution to the carbon black aggregates and their polymeric carriers. The Full Notched Creep Test (FNCT) was performed to determine the long-term creep performance of the black compounds; it is shown that the sample having more uniform comonomer distribution is more resistant compared to other samples. On the other hand, by addition of carbon black masterbatch, resistance to slow crack growth in samples decreases since carbon black aggregates can act as stress concentration spots in the structure. However, with addition of the masterbatch with LDPE carrier polymer, the reduction of this value in samples is lower compared to one with HDPE carrier. The reason for this observation is that long branches of LDPE polymer enter the structure of lamellae in the PE100 resins, making them more coherent and increasing the number of tie molecules. The samples that are blended with LDPE polymer have a rougher surface, which means linkage between two sides of crack was stronger due to higher entanglement density in these samples. The impact test confirms the same trend as FNCT test, with the sample containing LDPE carrier having higher impact strength.

Cole–Cole relation for long-chain branching from general rigid bead–rod theory

Empirically, we find that the parametric plots of the imaginary vs real parts of the complex viscosity may depend neither on temperature nor on average molecular weight. Moreover, for a fixed polydispersity, these viscosity Cole–Cole curves amplify both rightward and upward with long-chain branching content. In this paper, we find that general rigid bead–rod theory [O. Hassager, “Kinetic theory and rheology of bead–rod models for macromolecular solutions. II. Linear unsteady flow properties,” J. Chem. Phys. 60(10), 4001–4008 (1974)] can explain these rightward and upward amplifications. We explore the effects of branching along a straight chain in small-amplitude oscillatory shear flow. Specifically, we explore the number of branches, branch length, branch position, and branch distribution.

Lasercom optical-terminal performance testing platform

The lasercom optical-terminal performance testing platform (LCOT-PTP) is a precision optical system providing experimental testing of important characteristic parameters including transmitting power, beam divergence angle, far-field spot energy distribution and coaxialities of different branches in a lasercom optical terminal (LCOT). The LCOT-PTP consisting of a telescope, beam splitters, a receiving branch, a transmitting branch and a tracking test branch is developed. Due to the testing process requirements in coarse tracking, fine tracking and the assembly integration, the working wavelengths of 808nm, 1550nm and 632.8nm are adopted in testing-system design. By using the under-test LCOT parameters and Gaussian beam transmitting theory, the optical-system design is completed. Based on the established LCOT-PTP, the key performance testing work is accomplished.

Research on Single Grounding Location Technology of Power Grid Based on Wavelet Analysis

The research of single grounding location technology based on wavelet analysis aims at the current situation of complex distribution network structure, high failure rate, many branches of lines, large transition resistance, difficult to detect fault signals. This method analyzes the characteristics of fault traveling wave signal generated by single effective grounding, and filters the collected traveling wave signal by wavelet analysis, so as to improve the credibility of traveling wave signal characteristics. Through calculating the traveling wave line mode and zero mode component at the time of fault occurrence, the singular point of traveling wave waveform is obtained, and the fault point is determined by accurate traveling wave velocity. For the tree distribution system, the zero mode waveform of the reflected traveling wave is recorded by injecting the voltage ranging traveling wave into the system during normal operation, and the reflected traveling wave is injected into the fault phase during fault, and the zero mode voltage waveform of the reflected wave is recorded. The two waveforms are subtracted to eliminate the reflected wave head of the grid node, and the fault distance is calculated by wavelet analysis. The method needs to measure the current and voltage of each terminal of the line synchronously when the parameters of the line are known. Through the experiment of fault location for single-phase ground fault of multi branch distribution lines, the results show that this method is effective.

Temperature stage matching and experimental investigation of high-temperature cascade heat pump with vapor injection

High-temperature cascade heat pump has remarkable development potential for industrial heat generation due to its superiority in energy-saving and environment friendly. But the growing demand for higher temperature difference heating challenges the traditional cascade heat pump. One of practical solutions is the combination of cascade system and vapor injection technique. However, the introduction of vapor injection increases the complexity of the system, and the interaction between branches and the distributions of branches are to be studied to give full play to the best performance of the vapor injected cascade system. This paper focuses on temperature stage matching between the heat exchange branches of a cascade air source heat pump with vapor injection to get optimal heating performance. The optimal configurations of intermediate temperature and vapor injection branch temperature are obtained based on the optimal method. A cascade heat pump prototype with refrigerant R245fa and R410A is developed and investigated experimentally to verify the optimization method. The cascade air source heat pump could realize 140 °C heat supply and the coefficient of performance is from 1.16 to 1.58 under the ambient temperature of from −10 °C to 20 °C.