bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Automated Self‐Similarity Analysis of the Pulmonary Tree of the Sprague–Dawley Rat
Authors: Einstein Daniel R. , Neradilak Blazej , Pollisar Nayak , Minard Kevin R. , Wallis Chris , Fanucchi Michelle , Carson James P. , Kuprat Andrew P. , Kabilan Senthil , Jacob Richard E. , Corley Richard A. 
Published: October 2008

AbstractWe present the results of an automated analysis of the morphometry of the pulmonary airway trees of the Sprague–Dawley rat. Our work is motivated by a need to inform lower‐dimensional mathematical models to prescribe realistic boundary conditions for multiscale hybrid models of rat lung mechanics. Silicone casts were made from three age‐matched, male Sprague–Dawley rats, immersed in a gel containing a contrast agent and subsequently imaged with magnetic resonance (MR). From a segmentation of this data, we extracted a connected graph, representing the airway centerline. Segment statistics (lengths and diameters) were derived from this graph. To validate this MR imaging/digital analysis method, airway segment measurements were compared with nearly 1,000 measurements collected by hand using an optical microscope from one of the rat lung casts. To evaluate the reproducibility of the MR imaging/digital analysis method, two lung casts were each imaged three times with randomized orientations in the MR bore. Diameters and lengths of randomly selected airways were compared among each of the repeated imaging datasets to estimate the variability. Finally, we analyzed the morphometry of the airway tree by assembling individual airway segments into structures that span multiple generations, which we call branches. We show that branches not segments are the fundamental repeating unit in the rat lung and develop simple mathematical relationships describing these structures for the entire lung. Our analysis shows that airway diameters and lengths have both a deterministic and stochastic character. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
Requirement of TCTG(G/C) Direct Repeats and Overlapping GATA Site for Maintaining the Cardiac‐Specific Expression of Cardiac troponin T in Developing and Adult Mice
Authors: Harlan Shannon M. , Reiter Rebecca S. , Sigmund Curt D. , Lin Jenny Li‐Chun , Lin Jim Jung‐Ching 
Published: October 2008

AbstractThe cardiac‐specific −497 bp promoter of rat cardiac troponin T (cTnT) contains two similar modules, D and F, each of which possesses TCTG(G/C) direct repeats and A/T‐rich sites. To identify cis‐elements critical for cardiac specificity, a −249 bp promoter containing only module F and its site‐directed mutations were used to generate transgenic mice. Transgene expression of the −249 bp promoter remained cardiac‐specific, despite low and nonuniform expression. The nonuniform expression pattern of the transgene coincided with differential expression of HMGB1, which appeared to be the predominant form of HMGB family proteins in the heart. The HMGB1 binds to the A/T‐rich/MEF2‐like sites of the cTnT promoter, as determined by chromatin immunoprecipitation assays. Mice carrying the −249 bp promoter with point mutations disrupting the direct repeats expressed transgene at lower levels in the heart and ectopically in the brain. Ectopic expression of transgene was also observed in developing limbs and head. These results suggest an important role for the direct repeat in determining the cardiac specificity. Furthermore, mice carrying a mutant promoter simultaneously disrupting the direct repeats and overlapping GATA site failed to express the transgene in any tissues tested. Therefore, the direct repeat and overlapping GATA site are critical for the expression level and cardiac specificity. The F module controls one level of cardiac specificity. For a uniform and high level of cardiac‐specific expression, the upstream element (−497 to −250 bp) is further required, possibly through the D enhancer module and the combination of Nkx2.5 and GATA sites. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
The Phylogenetic Significance of Anthropoid Paranasal Sinuses
Authors: Rossie James B. 
Published: October 2008

AbstractIn this study, the phylogenetic significance of anthropoid paranasal sinus anatomy is explored. New information reported in recent years has precipitated new hypotheses of sinus homology and more than doubled the number of anthropoid genera for which confident assessments of sinus identity can be made. As a result, it is likely that the phylogenetic meaning of commonly cited characters such as the ethmoid and frontal sinuses will change. The traditional method of “character mapping” is employed to test hypotheses of sinus homology and to reconstruct the ancestral states for sinus characters in major anthropoid clades. Results show that most sinuses appear to be primitive retentions in anthropoids, with their absences in various genera representing losses. Accordingly, many of these sinuses are potential anthropoid synapomorphies. Anat Rec, 291:1485–1498, 2008. © 2008 Wiley‐Liss, Inc.
Nitric Oxide and the Paranasal Sinuses
Authors: Lundberg Jon O. 
Published: October 2008

AbstractThe discovery within the paranasal sinuses for the production of nitric oxide (NO) has altered the traditional explanations of sinus physiology. This review article reports the ongoing investigation of sinus physiology beginning with the discovery of NO gas production in the paranasal sinuses that occurred in 1995, and the impact that finding has had both in the basic science and clinical arenas. It was shown that healthy paranasal sinus epithelium expresses an inducible NO synthase that continuously generates large amounts of NO, a pluripotent gaseous messenger with potent vasodilating, and antimicrobial activity. This NO can be measured noninvasively in nasally exhaled breath. The role of NO in the sinuses is likely to enhance local host defense mechanisms via direct inhibition of pathogen growth and stimulation of mucociliary activity. The NO concentration in a healthy sinus exceeds those that are needed for antibacterial effects in vitro. In patients with primary ciliary dyskinesia (PCD) and in cystic fibrosis, nasal NO is extremely low. This defect NO generation likely contributes to the great susceptibility to chronic sinusitis in these patients. In addition, the low‐nasal NO is of diagnostic value especially in PCD, where nasal NO is very low or absent. Intriguingly, NO gas from the nose and sinuses is inhaled with every breath and reaches the lungs in a more diluted form to enhance pulmonary oxygen uptake via local vasodilation. In this sense NO may be regarded as an “aerocrine” hormone that is produced in the nose and sinuses and transported to a distal site of action with every inhalation. Anat Rec, 291:1479–1484, 2008. © 2008 Wiley‐Liss, Inc.
A Morphogenetic Model of Cranial Pneumatization Based on the Invasive Tissue Hypothesis
Authors: Zollikofer Christoph P.E. , Weissmann John D. 
Published: October 2008

AbstractThe interpretation of patterns of cranial pneumatization in terms of evolution, development, and function is controversial, because these structures exhibit extreme diversity and variability among and within taxa. However, there is general consensus that air‐filled spaces are formed by invasion of mucous epithelial tissue from the nasopharyngeal cavity into the surrounding cranial bones. This investigation presents a morphogenetic model of pneumatization, which combines empirical data about epithelial growth with physical concepts of surface growth. The study develops a model that defines growth equations with a minimum number of system parameters to simulate the invasion of mucous tissue and air‐filled spaces into the cancellous compartment of cranial bones. Computer simulations show that tuning a small set of model parameters permits generation of a wide diversity of morphologies mimicking natural air‐filled spaces. Comparison of virtual with actual morphologies yields new insights into possible factors controlling the process of cranial pneumatization. Anat Rec, 291:1446–1454, 2008. © 2008 Wiley‐Liss, Inc.
Independence of Biomechanical Forces and Craniofacial Pneumatization in Cebus
Authors: Rae Todd C. , Koppe Thomas 
Published: October 2008

AbstractSeveral different factors have been hypothesized as explanations of variation in primate paranasal sinus size. Biomechanical forces, particularly those associated with mastication, are frequently evoked to account for differences in primate craniofacial pneumatization. To test whether masticatory stresses are responsible for maxillary sinus volume diversity, two platyrrhine species of the genus Cebus (C. apella and C. albifrons) were examined. The former has been identified as a hard object feeder, and many morphological differences between the two species are attributable to differences in the mechanical properties of their respective diets. Sinus volumes were derived from serial coronal CT scans of the crania of adults. Several external cranial measurements were used to scale sinus volume relative to the size of the face. Relative measures of maxillary sinus volume were compared using standard statistical techniques. In all comparisons, the two capuchin species do not differ from one another significantly at P < 0.05. Thus, this “natural experiment” fails to support the interpretation that biomechanical forces acting on the facial skeleton substantially affect the degree of paranasal pneumatization in primates. This result suggests that it is unlikely that the maxillary sinus performs any function in relation to masticatory stress; other factors must be responsible for the variation in sinus volume among primates. Anat Rec, 291:1414–1419, 2008. © 2008 Wiley‐Liss, Inc.
The Paranasal Sinuses: The Last Frontier in Craniofacial Biology
Authors: Márquez Samuel 
Published: October 2008

AbstractThis special issue of the Anatomical Record explores the presence and diversity of paranasal sinuses in distinct vertebrate groups. The following topics are addressed in particular: dinosaur physiology; development; physiology; adaptation; imaging; and primate systematics. A variety of approaches and techniques are used to examine and characterize the diversity of paranasal sinus pneumatization in a wide spectrum of vertebrates. These range from dissection to histology, from plain X‐rays to computer tomography, from comparative anatomy to natural experimental settings, from mathematical computation to computer model simulation, and 2D to 3D reconstructions. The articles in this issue are a combination of literature review and new, hypothesis‐driven anatomical research that highlights the complexities of paranasal sinus growth and development; ontogenetic and disease processes; physiology; paleontology; primate systematics; and human evolution. The issue incorporates a wide variety of vertebrates, encompassing a period of over 65 million years, in an effort to offer insight into the diversity of the paranasal sinus complexes through time and space, and thereby providing a greater understanding and appreciation of these special spaces within the cranium. Anat Rec, 291:1350–1361, 2008. © 2008 Wiley‐Liss, Inc.
Cessation of Reproduction‐Related Spine Elongation After Multiple Breeding Cycles in Female Naked Mole‐Rats
Authors: Dengler‐Crish Christine M. , Catania Kenneth C. 
Published: October 2008

AbstractThe breeding female or “queen” naked mole‐rat has a uniquely elongated body morphology attributed to the lengthening of the lumbar vertebral column that occurs during pregnancy. It is unknown whether this vertebral growth is a continuous process, or associated only with early reproductive experience. We compared pregnancy‐related bone elongation in nascent primiparous queens and established queens to determine if this vertebral expansion was a lifelong process in these females. We also investigated the impact of lactation on vertebral elongation in these mole‐rats because it is known to be a time of significant bone loss in other mammals. Our data show that after eight or more pregnancies, established queens no longer experienced a net gain in lumbar spine length over the reproductive cycle, whereas the nascent breeders demonstrated significant spine lengthening over this time. Despite the lack of net spine lengthening in established breeders, our results indicated that these queens still experienced some pregnancy‐specific vertebral elongation. In naked mole‐rats, pregnancy‐induced bone elongation may serve the dual purposes of first lengthening the spine, and then once optimal spine size is achieved, serving as a homeostatic mechanism that prepares the spine for the mineral demands of lactation. Anat Rec, 2009. © 2008 Wiley‐Liss, Inc.
The Paranasal Air Sinuses of Predatory and Armored Dinosaurs (Archosauria: Theropoda and Ankylosauria) and Their Contribution to Cephalic Structure
Authors: Witmer Lawrence M. , Ridgely Ryan C. 
Published: October 2008

AbstractThe paranasal air sinuses and nasal cavities were studied along with other cephalic spaces (brain cavity, paratympanic sinuses) in certain dinosaurs via CT scanning and 3D visualization to document the anatomy and examine the contribution of the sinuses to the morphological organization of the head as a whole. Two representatives each of two dinosaur clades are compared: the theropod saurischians Majungasaurus and Tyrannosaurus and the ankylosaurian ornithischians Panoplosaurus and Euoplocephalus. Their extant archosaurian outgroups, birds and crocodilians (exemplified by ostrich and alligator), display a diversity of paranasal sinuses, yet they share only a single homologous antorbital sinus, which in birds has an important subsidiary diverticulum, the suborbital sinus. Both of the theropods had a large antorbital sinus that pneumatized many of the facial and palatal bones as well as a birdlike suborbital sinus. Given that the suborbital sinus interleaves with jaw muscles, the paranasal sinuses of at least some theropods (including birds) were actively ventilated rather than being dead‐air spaces. Although many ankylosaurians have been thought to have had extensive paranasal sinuses, most of the snout is instead (and surprisingly) often occupied by a highly convoluted airway. Digital segmentation, coupled with 3D visualization and analysis, allows the positions of the sinuses to be viewed in place within both the skull and the head and then measured volumetrically. These quantitative data allow the first reliable estimates of dinosaur head mass and an assessment of the potential savings in mass afforded by the sinuses. Anat Rec, 291:1362–1388, 2008. © 2008 Wiley‐Liss, Inc.
Untersuchungen zur Dauerhaftigkeit von Verbindungen und Anschlüssen bei Luftdichtheitsschichten mittels Klebemassen und Klebebändern
Authors: Cammerer Johannes , Ackermann Thomas , Spitzner Martin H. 
Published: October 2008

AbstractDie Ausbildung der luftdichten Gebäudehülle erfordert in vielen Fällen das Verkleben von luftdichten Bahnen untereinander und mit angrenzenden Bauteilen. Planungs‐ und Ausführungsempfehlungen für die Herstellung der Luftdichtheit von Gebäuden unter Verwendung von Luftdichtheitsschichten und Klebemitteln sind in DIN 4108‐7 beschrieben, wobei die Leistungsfähigkeit der Klebeverbindungen nicht bekannt ist.Zur Untersuchung der Haltbarkeit von Verklebungen kurz nach der Verarbeitung und zur Untersuchung der Dauerhaftigkeit von Klebeverbindungen wurden Luftdichtheitssysteme ausgesucht, die von Herstellern als Kombinationen aus Luftdichtheitsbahnen und Klebemitteln angeboten werden. Die Schälwiderstände dieser Klebeverbindungen wurden nach unterschiedlichen Konditionierungen und nach beschleunigten Alterungen geprüft. Ein neu entwickeltes Verfahren prüft auch die Auswirkungen von Scherkräften auf die Klebeverbindungen.Die Untersuchungsergebnisse zeigen deutliche Unterschiede der ermittelten Schäl‐ und Scherkräfte zwischen den Produktkombinationen Klebemasse/Luftdichtheitsbahn der verschiedenen Hersteller. Der Einfluss der unterschiedlichen künstlichen Alterungen auf die Schälkräfte einer Produktkombination stellte sich dagegen als geringfügig heraus, wodurch eine zuverlässigere Beurteilung künstlicher Alterungsmethoden ermöglicht wird.
Optical Absorption Property and Photo‐catalytic Activity of Tin Dioxide‐doped Titanium Dioxides
Authors: LI Huai‐Xiang , XIA Rong‐Hua , JIANG Zheng‐Wei , CHEN Shan‐Shan , CHEN De‐Zhan 
Published: October 2008

AbstractSnO2‐doped TiO2 films and composite oxide powders have been prepared by a sol‐gel method. Ti(OC4H9)4 and SnCl4·5H2O were used as precursors and C2H5OH was used as solvent. The optical absorption measurements indicate that the composite oxide SnO2‐TiO2 thin films exhibit smaller optical energy band gaps than pure TiO2 thin films and the optical energy band gap decreases as calcining temperature increases. X‐ray diffraction was used to characterize the phase transition for the composite oxide powders at different calcining temperatures. Aanatase phase is the main crystal structure in both pure TiO2 and Sn0.05Ti0.95O2samples if calcining temperature is below 500 °C. The rutile phase has appeared and coexisted with the anatase crystal phase for both pure TiO2 and Sn0.05Ti0.95O2 composite oxides when calcining was at 600 °C. Transmission electron microscopy analysis shows a smaller grain size in Sn0.05Ti0.95O2 powders than TiO2 powders calcined at 600 °C. When calcining temperature is 700 °C, there is only rutile phase in Sn0.05Ti0.95O2 samples, but there are still two crystal phases, anatase and rutile, coexisting in the pure TiO2 samples. Assuming the grain growth obeys the first order kinetics, Arrhenius empirical relation has been used to estimate the activation energy of 47.486 and 33.103 kJ·mol−1 for the grain growth of TiO2 and Sn0.05Ti0.95O2, respectively. The photo‐catalytic activity of the powder samples has been examined by measuring the degradation of methylene blue solution under ultra‐violet irradiation. Two effective factors of photo‐catalytic activity namely, the content of SnO2 in the TiO2 samples and the calcining temperature, have been optimized based on the photo‐catalytic degradation of methylene blue solution.
Synthesis and Characterization of Camptothecin Intercalated into Mg/Al Layered Double Hydroxide
Authors: LIU Chun‐Xia , HOU Wan‐Guo , LI Yan , LI Li‐Fang 
Published: October 2008

AbstractThe intercalation of camptothecin (CPT) into a layered inorganic host, Mg‐Al layered double hydroxide (LDH), was carried out using a coprecipitation method to obtain CPT‐LDH nanohybrids. It was found that the intercalated amounts (Ain) of CPT‐LDH nanohybrids were remarkably dependent on the molar ratios (RC/M) of CPT to metal ions in raw materials. The Ain value increases with the RC/M value increasing. According to the gallery heights of CPT‐LDH and sizes of CPT molecule, a probably morphology of CPT molecules in the gallery of LDH was suggested that the horizontal‐arranged monolayer and vertical‐arranged bilayer of CPT molecules coexisted in the interlayer region of LDH. An interesting result was found that the gallery height corresponding to the bilayer of CPT‐LDH sample with a high Ain value was remarkably lower than that with low Ain value. The in vitro CPT release examinations from the nanohybrids showed that the CPT‐LDH nanohybrids were a potential drug controlled release system. The kinetic analysis showed that the release kinetics of CPT from the nanohybrids obeyed the pseudo‐first order kinetic model and the diffusion of CPT through the LDH particle of CPT played an important role in controlling the drug release rate.
Metastable Equilibria for the Quaternary System Li2B4O7+Na2B4O7+K2B4O7+H2O at 15 °C
Authors: SANG Shi‐Hua , YIN Hui‐An , NI Shi‐Jun , DENG Miao 
Published: October 2008

AbstractMetastable equilibrium solubilities and such physico‐chemical properties as densities, conductivity, pH, refractive index and viscosity of the solution for the quaternary system Li2B4O7+Na2B4O7+K2B4O7+H2O at 15 °C were determined experimentally. According to the experimental data, the metastable equilibrium phase diagram was plotted. In the metastable phase diagram, there are one invariant point, three univariant curves, and three fields of crystallization: Li2B2O4·16H2O, Na2B4O7·10H2O, and K2B4O7·4H2O. Potassium borate (K2B4O7·4H2O) has the smallest crystallization field and sodium borate (borax) has the biggest one. Also, the relationship diagram between the properties and the ion concentration of solution was constructed. It can be seen from the relationship diagram that the metastable equilibrium solution density values, viscosity values and refractive index values are increased apparently with the rise of lithium borate concentration, reaching the maximum values at invariant point F. Electrical conductivity values and pH values, however, fall down with the rise of ion concentration on the whole.
Synthesis, Crystal Structures and Thermal Stabilities of [Cu(bpp)2(bpdc)(H2O)2]n·2nH2O and [Cu(bpp)2]n·n (tdc) ·7.5nH2O
Authors: YU Jing‐Hua , WANG Zhong‐Ming , LUO Xin‐Ze , DU Hong‐Guang 
Published: October 2008

AbstractTwo novel copper(II) coordination polymers [Cu(bpp)2(bpdc)(H2O)2]n·2nH2O (1) and [Cu(bpp)2]n·n(tdc)·7.5nH2O (2) (H2bpdc=biphenyl‐4,4′‐dicarboxylic acid, bpp=1,3‐di(4‐pyridyl)propane and H2tdc=thiophene‐2,5‐dicartboxylic acid) have been synthesized by the reactions of Cu(NO3)2 and bpp with the H2bpdc or H2tdc, respectively at room temperature. In the complexes 1 and 2, their Cu atoms have a distorted octahedral geometry, and two water molecules coordinate weakly to the Cu atom in the long axial direction. Both complexes have one‐dimensional linear polymer structures. In complex 1, both carboxylate groups of the bpdc can coordinate to Cu atom, while both carboxylate groups of the tdc dianion in complex 2 do not coordinate to the Cu atom, which only balance the charge. In the both complexes, the bpp ligand has different conformation: trans‐trans in complex 1 and trans‐gauche in complex 2. The thermal gravimetric analyses indicate that both complexes are stable under 110 and 160 °C, respectively.
Facile Size‐controllable Aqueous Synthesis of Water Soluble CdTe/Cd(OH)2 Core/Shell Nanoparticles with Tunable Optical Property, High Quantum Yield and Good Stability
Authors: CAI Zhao‐Xia , CHEN Ying‐Jun , YAN Xiu‐Ping 
Published: October 2008

AbstractA facile procedure was developed to prepare size‐tunable and water soluble CdTe/Cd(OH)2 core/shell nanoparticles with high quantum yields and good stability using inexpensive inorganic precursors (CdCl2 and elemental Te). The emission colors of the prepared CdTe/Cd(OH)2 core/shell nanoparticles can be readily tuned from cyan to salmon pink by varying incubation time to control the growth of the Cd(OH)2 shell onto the CdTe nanoparticles. The CdTe/Cd(OH)2 core/shell nanoparticles were characterized by transmission electron microscopy, high‐resolution transmission electron microscopy, X‐ray powder diffraction spectrometry, photoluminescence and UV‐Vis spectrometry. The good water‐soluble nature of the CdTe/Cd(OH)2 core/shell nanoparticles offers great potentiality for their bio‐labeling application. This approach is simple, mild and readily scaled up, affording a simple way for synthesis of size‐tunable inorganic metal hydroxide capped core/shell nanoparticles.