Three-dimension Structure Research Articles

The design and construction of an electrohydrodynamic cartesian robot for the preparation of tissue engineering constructs.

In this work we bring together replicating rapid prototyping technology with electrohydrodynamic phenomena to develop a device with the ability to build structures in three-dimensions while simultaneously affording the user a degree of designing versatility and ease that is not seen in conventional computer numerically controlled machines. An attempt at reproducing an actual human ear using polycaprolactone was pursued to validate the hardware. Five different polycaprolactone solution concentrations between 7–15 wt% were used and printing was performed at applied voltages that ranged from 1 to 6 kV and at flow rates from 5µl/min to 60µl/min. The corresponding geometrical and aesthetic features of the printed constructs were studied to determine the effectiveness of the device. The 15 wt% concentration at 60µl/min under an applied electric field of 6 kV was identified as the best operating parameters to work with.

Layer-by-layer immobilized catalase on electrospun nanofibrous mats protects against oxidative stress induced by hydrogen peroxide.

Catalase, a kind of redox enzyme and generally recognized as an efficient agent for protecting cells against hydrogen peroxide (H2O2)-induced cytotoxicity. The immobilization of catalase was accomplished by depositing the positively charged chitosan and the negatively charged catalase on electrospun cellulose nanofibrous mats through electrospining and layer-by-layer (LBL) techniques. The morphology obtained from Field emission scanning electron microscopy (FE-SEM) indicated that more orderly arranged three-dimension (3D) structure and roughness formed with increasing the number of coating bilayers. Besides, the enzyme-immobilized nanofibrous mats were found with high enzyme loading and activity, moreover, X-ray photoelectron spectroscopy (XPS) results further demonstrated the successful immobilization of chitosan and catalase on cellulose nanofibers support. Furthermore, we evaluated the cytotoxicity induced by hydrogen peroxide in the Human umbilical vascular endothelial cells with or without pretreatment of nanofibrous mats by MTT assay, LDH activity and Flow cytometric evaluation, and confirmed the pronounced hydrogen peroxide-induced toxicity, but pretreatment of immobilized catalase reduced the cytotoxicity and protected cells against hydrogen peroxide-induced cytotoxic effects which were further demonstrated by scanning electron microscopy (SEM) and Transmission Electron Microscopy (TEM) images. The data pointed toward a role of catalase-immobilized nanofibrous mats in protecting cells against hydrogen peroxide-induced cellular damage and their potential application in biomedical field.

Plotting Cranial and Spinal Nerve Pathways in a Human Anatomy Lab

Hands-on experiences with cadavers, animal dissections, or plastic models are effective at improving student learning and attitudes in human anatomy courses. The hands-on experience allows students to visualize and experiment with anatomical structures in three-dimensions, which is critical to learning the spatial organization of the human body. One area of human anatomy that is especially essential to understand in three dimensions is the pathways that cranial and spinal nerves take throughout the body. While human anatomy textbooks give two-dimensional and cadaver images of the routes that these nerves take, it is sometimes difficult to visualize the actual path that nerves take through the body without using a physical model. In this lesson, I describe an easily adaptable and expandable framework for students to learn about cranial and spinal nerve pathways in a human anatomy lab. Students use string or twine to model the pathways of nerves on human skeleton models and thus are able to better learn the origins, pathways, and innervation points of these nerves. This lesson will be of value to instructors of human anatomy labs who want to give their students a hands-on activity in the identification, plotting, and analysis of cranial and spinal nerve pathways.

Chapter One - Adenosine Receptor Neurobiology: Overview

Adenosine is a naturally occurring nucleoside that is distributed ubiquitously throughout the body as a metabolic intermediary. In the brain, adenosine functions as an important upstream neuromodulator of a broad spectrum of neurotransmitters, receptors, and signaling pathways. By acting through four G-protein-coupled receptors, adenosine contributes critically to homeostasis and neuromodulatory control of a variety of normal and abnormal brain functions, ranging from synaptic plasticity, to cognition, to sleep, to motor activity to neuroinflammation, and cell death. This review begun with an overview of the gene and genome structure and the expression pattern of adenosine receptors (ARs). We feature several new developments over the past decade in our understanding of AR functions in the brain, with special focus on the identification and characterization of canonical and noncanonical signaling pathways of ARs. We provide an update on functional insights from complementary genetic-knockout and pharmacological studies on the AR control of various brain functions. We also highlight several novel and recent developments of AR neurobiology, including (i) recent breakthrough in high resolution of three-dimension structure of adenosine A2A receptors (A2ARs) in several functional status, (ii) receptor-receptor heterodimerization, (iii) AR function in glial cells, and (iv) the druggability of AR. We concluded the review with the contention that these new developments extend and strengthen the support for A1 and A2ARs in brain as therapeutic targets for neurologic and psychiatric diseases.

Theory and Simulation Analysis of the Mode Shape and Normal Shape Actuators and Sensors

In this paper, we will try to find a universal theoretical model and approximate solutions which can be applied to both mode shape and normal shape actuators and sensors, and which can be predicted the gain of the first three modes of the mode shape and normal shape actuators and sensors, finally through computer simulation analysis to validate. In order to prove the feasibility of the theory and as well as convenient to use on the electro-mechanical engineering, we will try to simplify the three-dimension structure problem into an one-dimension structure problem. Furthermore we will design one kind of bimorph type piezoelectric cantilever beam, so that it can be used as with the actuator and sensor simultaneously, but also conducive to the theory and simulation analysis. As for the simulation analysis, we will use the ANSYS code.

Molecular cloning and characterization of the pseudorabies virus UL31 gene

We amplified a 816-bp sequence of the UL31 gene from the pseudorabies virus (PRV) Becker strain genome. Evidence that this was the UL31 gene was confirmed by cloning and sequencing. The PRV UL31 gene encodes a putative protein of 271-amino acid residues, which was designated the UL31 protein. Bioinformatic analysis indicated that PRV UL31 contains a conserved PHA03328 domain, closely related with the herpes virus nuclear egress lamina protein UL31 family and highly conserved among counterparts encoded by herpes UL31 genes. Nucleic acid sequence and amino acid sequence alignments demonstrated that PRV UL31 has a relatively higher homology with UL31 homologous proteins of subfamily Alphaherpesvirinae than other subfamilies. In addition, phylogenetic analysis showed that PRV UL31 has a close evolutionary relationship with members of the subfamily Alphaherpesvirinae, especially bovine herpesvirus 1 (BoHV-1), BoHV-5, equine herpesvirus 4 (EHV-4), EHV-9 and EHV-1. Antigen prediction demonstrated that several potential B-cell epitopes are located in PRV UL31. Additionally, secondary structure and three-dimension structure prediction revealed that PRV UL31 predominantly consists of α-helix. Taken together, these results provide insight on the function and mechanism of UL31 during PRV infection.

Reliability and validity of a Chinese version of the attitudes toward obese persons scale among nursing college students

Objective To evaluate the reliability and validity of a Chinese version of the attitudes toward obese persons(ATOP)scale among college nursing students.Methods A Chinese version of ATOP was obtained by forward translation, synthesis,back translation,and culture adjusting;the content validity was examined by expert committee review.A total of 407 valid questionnaires of Chinese ATOP were completed by a convenient sample of college nursing students.The psychometric properties of ATOP were examined by content validity index(CVI)for content validity,critical ratio(CR)for item analysis, factor analysis for construct validity and Cronbach's alpha coefficient for internal consistency reliability.Additionally,the intra-class correlation coefficient(ICC)for test-retest reliability was tested in 20nursing students after a two-week interval. Results The mean CVI of the Chinese version of ATOP was 0.97.The final Chinese version comprised 12items and reflected 3 dimensions:different personalities,social difficulties and self-esteem,which explained 52.45% of the total variance. Confirmatory factor analysis further supported this three-dimension structure(χ2=93.75,df=51,χ2/df=1.84,RMSEA= 0.06,NNFI=0.91,CFI=0.93,IFI=0.93,GFI=0.93,AGFI=0.89).The criterion-related validity was confirmed by the positive correlation between the total scores for ATOP and its subscale scores and the scores for internal weight locus of control. The internal consistency reliability evaluated by Cronbach's alpha was 0.59-0.71for the three subscales and the whole scale. The test-retest reliability across two weeks ranged from 0.52to 0.83.There was a weak negative correlation between body mass index(BMI)and the self-esteem score.Nursing students who perceived themselves as overweight scored lower in the self-esteem factor and higher in the factor of different personality than those who did not.Conclusion The Chinese version of ATOP has satisfactory validity and acceptable reliability in measuring the attitudes toward obese persons,and can be used to evaluate the attitude of nursing students toward obesity.

Dynamic Analysis of Tall Building Structure Based on Ansys

This paper uses the finite element analysis software Ansys to model a tall building structure in three-dimensions, then analyze the modal and the response of the structure under wind and earthquake. It provides some references to the dynamic analysis of tall building structure.

UV-Raman Microscopy on the Analysis of Ultra-Low-K Dielectric Materials on Patterned Wafers

With the shrinkage of the IC device dimension, Cu and ultra-low-k dielectric were introduced into IC devices to reduce the RC delay. Ultra-low-k dielectrics generally suffer more damage than silicon oxide dielectric during process integration and subsequently cause reliability degradation. Therefore, ultra-low-k damage characterization on Cu damascene structures is of great importance to understand the damage mechanisms. This paper describes the application of UV-Raman microscopy with enhanced spatial resolution and signal sensitivity for characterizing ultra-low-k dielectric in the three-dimension structure of Cu metallization with nanometer feature size. It shows UV-Raman technique has an advantage in analyzing ultra-low-k layer on patterned wafer and extracting ultra-low-k signals from Cu/ultra-low-k mixed structure. UV-Raman is also effective to characterize the ultra-low-k degradation for ultra-low-k related reliability analysis by time dependent dielectric breakdown (TDDB) test.

Molecular Cloning, Expression of minD Gene from Lactobacillus acidophilus VTCC-B-871 and Analyses to Identify Lactobacillus rhamnosus PN04 from Vietnam Hottuynia cordata Thunb.

The minD gene encoding an inhibitor cell division MinD homolog from Lactobacillus acidophilus VTCC-B-871 was cloned. We showed that there were 97% homology between minD genes of L. acidophilus VTCC-B-871 and Lactobacillus rhamnosus GG and Lactobacillus rhamnosus Lc705. Based on the analysis of the DNA sequence data from the L. rhamnosus genome project and sequenced minD gene of L. acidophilus VTCC-B-871, a pair of primers was designed to identified the different minD genes from L. acidophilus ATCC 4356, L. rhamnosus ATCC 11443. Besides, the polymerase chain reaction product of minD gene was also obtained in L. rhamnosus PN04, a strain was isolated from Vietnamese Hottuynia cordata Thunb. In addition, we performed a phylogenetic analysis of the deduced amino acid sequence of MinD homologs from L. acidophilus VTCC-B-871 with the other strains and compared the predicted three-dimension structure of L. acidophilus VTCC-B-871 MinD with Escherichia coli MinD, there are similarity that showed evolution of these strains. The overexpression of L. acidophilus VTCC-B-871 MinD in E. coli led to cell filamentation in IPTG and morphology changes in different sugar stresses, interestingly. The present study is the first report characterizing the Lactobacilus MinD homolog that will be useful in probiotic field.

An investigation of transient nature of the cavitating flow in injector nozzles

In diesel engines, the cavitating flow in nozzles greatly affects the fuel atomization characteristics and then the subsequent combustion and exhaust emissions. In this paper, with the needle lift curve on the basis of injection rate experimental data, a moving mesh generation strategy was applied for 3D simulation of the nozzle cavitating flow. Based on the third-generation synchrotrons of Shanghai Synchrotron Radiation facility (SSRF), a high-precision three-dimension structure of testing nozzle with detailed internal geometry information was obtained using X-ray radiography for a more accurate simulation. A flow visualization experiment system with a transparent scaled-up vertical multi-hole injector nozzle tip was setup. The experimental data was obtained to make a comparison to validate the calculated results and good qualitative agreement was shown between them. Afterward, the effects of needle movement on development of the cavitating flow and flow characteristics parameters were investigated. Finally, the influence of fuel temperature on development of the cavitating flow was also studied. Research of the flow characteristics for the diesel and biodiesel revealed that the flow characteristics of the biodiesel with a temperature rise of between 50 K and 60 K in injector nozzles will be similar to those of the diesel fuel.

Mannan Loaded Biodegradable and Injectable Thermosensitive PCL-PEG-PCL Hydrogel for Vaccine Delivery

In this study, we aimed to develop a novel mannan loaded in situ gel-forming controlled protein delivery system for vaccine to improve humoral immunity. Preparation and potential application of mannan loaded biodegradable and injectable thermosensitive poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL, PCEC) hydrogel (M-hydrogel) was investigated. The prepared M-hydrogel is a free flowing sol at low temperature, which can be mixed with basic fibroblast growth factor (bFGF) easily, and forms a non-flowing gel at body temperature acting as in situ sustained delivery depot. Moreover, the interior morphology of bFGF-loaded M-hydrogel (bFGF-M-hydrogel) was studied, which showed porous three-dimension structure. In addition, in vitro release assay indicated that bFGF could be released from the M-hydrogel system in a controlled manner. Furthermore, in vivo experiments indicated that the immunogenicity of bFGF was improved significantly after encapsulated into M-hydrogel, which was significantly higher than that of normal saline (NS), blank hydrogel, pure bFGF, bFGF loaded hydrogel (bFGF-hydrogel), bFGF and mannan mixture (bFGF-M), and bFGF loaded Complete Freund's Adjuvant (bFGF-CFA) groups. Therefore, M-hydrogel is believed to be promising as an in situ gel-forming controlled protein delivery system for vaccine.

Nanofibrous mats layer-by-layer assembled via electrospun cellulose acetate and electrosprayed chitosan for cell culture

Negatively charged cellulose acetate (CA) and positively charged chitosan (CS) were layer-by-layer (LBL) assembled together by the electrospinning–electrospraying hybrid technique via physical deposition and electrostatic force for the first time. The morphology of the mats indicated that all of them were of a good fiber shape and a three-dimension structure. The X-ray photoelectron spectroscopy results verified the existence of CS on the surface of the as-spun mats. The thermogravimetric analysis and differential scanning calorimetry results illustrated that the thermal properties of the mats were affected by their compositions. In addition, the cell culture experiment demonstrated that the scaffolds with the LBL structured polysaccharide films were of good cell compatibility and no cytotoxicity for the mouse lung fibroblasts cells. Moreover, the ability of cell adhesion and spreading was affected by the number of deposition layers and the composition of outermost layer.

Conformal Ni-silicide formation over three-dimensional device structures

This letter reports on conformal formation of ultrathin Ni-silicide films over a three-dimension structure relevant to the most advanced tri-gate transistor architecture. This is achieved by combining ionization of the sputtered Ni atoms with application of an appropriate bias to the Si substrate during the sputter-deposition of Ni films. In comparison, use of ordinary DC sputtering for Ni deposition results in thinner or less uniform silicide films on the vertical sidewalls than on the top surface of the three-dimensional structure. The roughened Si sidewall surface is ascribed to be responsible for a deteriorated thermal stability of the resultant silicide films.

Novel building units in the construction of materials of the oxomolybdate–organodiphosphonate/copper(II)–dipodal-organonitrogen ligand system: Structural influences of dipodal ligand tether length and flexibility

The hydrothermal reactions of copper(II) acetate, MoO3, 1,4-butylenediphosphonic acid and a ligand of the N,N,N′,N′-tetrakis(pyridine-2-ylmethyl)alkyl-α,ω-diamine (Ln, where n is the number of methylene groups) in the presence of HF provided crystals of [{Cu2(L7)(H2O)2}Mo5O15{O3P(CH2)4PO3}]·2H2O (1·2H2O) and [{Cu2(L5)}Mo6O18(H2O){O3P(CH2)4PO3}]·14H2O (2·14H2O). Compound 1 contains the common pentanuclear cluster building block {Mo5O15(O3PR)2}4−, extending into one-dimensional chains through the alkyl tethers of the diphosphonate ligand. Each pentanuclear subunit bonds to four copper(II) sites of the {Cu2(L7)(H2O2)}4+ subunits that serve to link each chain to five adjacent chains to propagate the structure in three dimensions. The Cu/Mo/P/O inorganic substructure which arises from this juxtaposition of building motifs is a one-dimensional {Cu2Mo5O15(O3P−)2} unit consisting of clusters linked through Cu(II) sites. The alkyl arms of the diphosphonate and nitrogen ligands radiate outward to link to adjacent chains and propagate the structure in three-dimensions. In contrast, compound 2 exhibits a hexanuclear building unit {Mo6O18(H2O)(O3P−)2}4−, which again extends into a chain through the tethering diphosphonate ligands. Each cluster bonds to four Cu(II) centers to generate one-dimensional inorganic substructures of the type {Cu2Mo6O18(H2O)(O3P−)2}n. In contrast to 1, the {Cu2(L5)}4+ subunits of 2 associate with a single chain, rather than radiating outward to link to adjacent chains. Consequently, the three-dimensional expansion is effected through the diphosphonate tethers.

Validation de l’inventaire des facteurs de résilience (IFR-40)

Bekaert, Masclet and Caron's inventory of resilience factors (IRF-40) is a French measurement scale which measures the protection factors combining to bring about resilience in adolescents. This three-dimension measurement instrument has been worked out on the basis of a literary review aiming at identifying all the protection factors reported in the research studies. An exploratory factorial analysis with oblimin rotation carried out on a sample of 299 adolescents enabled to underline the three-dimension structure (familial protection factors: personal protection factors; extra-familial protection factors) including 40 items. The study of the internal consistency reveals high coefficients for the whole scale (0.91) as well as for the different dimensions (0.77 to 0.91). The examination of the convergent validity shows significant correlations with the life satisfaction scale (r=0.61) and the psychological well-being scale (r=0.72). As for the temporal stability (n=73), a measure of 0.92 was obtained. The present research aims at completing the evaluation of the psychometric properties of the IRF-40 on a sample of adolescents. With the intention of bringing to light the structure of the instrument, a confirmatory factorial analysis (CFA) was carried out on 414 adolescents (average age=14.96). The analyses carried out approve of the three-dimension structure of the scale. The study of the divergent validity (n=123) has brought to light a high and significant correlation (r=–0.757) between the IRF-40 and Berndt and Kaiser’ s composite depression scale as well as a significant correlation between the IRF-40 and the under scale of the MDI-C (r varies between –0.294 and –0.563). In addition, the IRF-40 enables to differentiate the adolescents exposed to a traumatism and who have depression scores to those who experience no depression. Indeed, the participants not experiencing depression obtain significantly higher scores on the IRF-40 (U=282.5; P=0.001) in comparison with the participants experiencing depression. What is more, it appears that the latter score lower familial protection factors (U=443.5; P=0.001), personal protection factors (U=390; P=0.001) and extra-familial factors (U=629; P=0.001) than those who do not experience depression. As a conclusion, the results of the present study show a very probant image of the psychometric qualities of the IRF-40 and support its use on a population of adolescents.

Biofilm: A dental microbial infection

Recent advances in research technology have allowed researchers to study bacteria in their natural environment. Dental biofilm forms via an ordered sequence of events, resulting in structured and functionally organized species rich microbial community and modern molecular biological techniques have identified about 1000 different bacterial species in the dental biofilm, twice as many as can be cultured. Sites for biofilm formation include all kinds of surfaces: natural materials above and below ground, metals, plastics, medical implant materials—even plant and body tissue. Wherever you find a combination of moisture, nutrients and a surface, you are likely to find biofilm. The biofilm is used to describe the communities of micro-organisms attached to a surface; such microbes are usually spatially organized into three-dimension structure and are enclosed in matrix of extracellular material derived both from the cells themselves and from the environment. Dental biofilm pathogenicity in the oral cavity is magnified by specific biofilm characteristics and modern molecular biological techniques have identified about 1000 different bacterial species in the dental biofilm, twice as many as can be cultured. Adaptation to a biofilm lifestyle involves regulation of a vast set of genes, and the micro-organisms are thus able to optimize phenotypic properties for the particular environment.

Cranial neural crest cells on the move: Their roles in craniofacial development

The craniofacial region is assembled through the active migration of cells and the rearrangement and sculpting of facial prominences and pharyngeal arches, which consequently make it particularly susceptible to a large number of birth defects. Genetic, molecular, and cellular processes must be temporally and spatially regulated to culminate in the three-dimension structures of the face. The starting constituent for the majority of skeletal and connective tissues in the face is a pluripotent population of cells, the cranial neural crest cells (NCCs). In this review we discuss the newest scientific findings in the development of the craniofacial complex as related to NCCs. Furthermore, we present recent findings on NCC diseases called neurocristopathies and, in doing so, provide clinicians with new tools for understanding a growing number of craniofacial genetic disorders.

Three-dimension structure of ventricular myocardial fibers after myocardial infarction

BackgroundTo explore the pathological changes of three-dimension structure of ventricular myocardial fibers after anterior myocardial infarction in dog heart.MethodsFourteen acute anterior myocardial infarction models were made from healthy dogs (mean weight 17.6 ± 2.5 kg). Six out of 14 dogs with old myocardial infarction were sacrificed, and their hearts were harvested after they survived the acute anterior myocardial infarction for 3 months. Each heart was dissected into ventricular myocardial band (VMB), morphological characters in infarction region were observed, and infarct size percents in descending segment and ascending segment were calculated.ResultsSix dog hearts were successfully dissected into VMB. Uncorresponding damages in myocardial fibers of descending segment and ascending segment were found in apical circle in anterior wall infarction. Infarct size percent in the ascending segment was significantly larger than that in the descending segment (23.36 ± 3.15 (SD) vs 30.69 ± 2.40%, P = 0.0033); the long axis of infarction area was perpendicular to the orientation of myocardial fibers in ascending segment; however, the long axis of the infarction area was parallel with the orientation of myocardial fibers in descending segment.ConclusionsWe found that damages were different in both morphology and size in ascending segment and descending segment in heart with myocardial infarction. This may provide an important insight for us to understand the mechanism of heart failure following coronary artery diseases.

Tetraquark state and multibody interaction

The tetraquark states with diquark--anti-diquark configuration have been studied in the flux-tube model, in which the multibody confinement is used. In this model approach, the states $Y(2175)$, ${f}_{0}(600)$, ${f}_{0}(980)$, and $X(1576)$ can be assigned as tetraquark states. They are color confinement resonances with three-dimension structure. This study suggests that the multibody confinement should be employed in the quark model study of multiquark states instead of the additive two-body confinement.