scholarly journals Anuran Heart Metamorphosis: Anatomical Support for Pulmonary Blood Separation in the Early Aquatic Phase

2021 ◽  
Author(s):  
Nina Kraus ◽  
Brian Metscher
Keyword(s):  
Complex Structure ◽  
Bufo Bufo ◽  
Respiratory Physiology ◽  
X Ray ◽  
Blood Separation ◽  
Gill Chamber ◽  
Single Opening ◽  
2D Imaging ◽  
Aortic Arches ◽  
Partial Resorption

Background: In both larval and adult anurans, blood separation and respiratory physiology have remained an enigma. While various blood separation mechanisms have been proposed, the same structure is seen as playing a key role: the conus arteriosus. However, previous findings on its internal structure are contradictory, depending on the specifics of the 2D imaging methods used by different authors. To resolve this problem, we used high-resolution X-ray microtomography of whole Bufo bufo specimens to acquire the first detailed 3D descriptions of this complex structure through metamorphosis. Results: In early tadpoles two small valvular openings develop at the ventricular-conal junction, providing two paths separated by the septum coni and continuing into the aortic arches. Thus, structures to support segregated pulmonary circulation are fully developed well before the lungs appear. The external gills undergo partial resorption and retreat asymmetrically into a gill chamber formed by a hyoidal cover, leaving only a single opening on the left side, the opercular spout. Conclusions: The timing of events in Bufo circulatory development does not track the changing modes of respiration used by the developing tadpole. In particular, a system capable of double circulation carries only oxygen-depleted blood for a significant portion of the tadpole stage.

scholarly journals Protein–ligand complex structure from serial femtosecond crystallography using soaked thermolysin microcrystals and comparison with structures from synchrotron radiation

2017 ◽  
Vol 73 (8) ◽  
pp. 702-709 ◽  
Author(s):  
Hisashi Naitow ◽  
Yoshinori Matsuura ◽  
Kensuke Tono ◽  
Yasumasa Joti ◽  
Takashi Kameshima ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Room Temperature ◽  
Complex Structure ◽  
Binding Mode ◽  
Ligand Complex ◽  
X Ray ◽  
Cell Parameters ◽  
Serial Femtosecond Crystallography ◽  
Small Molecule Ligand

Serial femtosecond crystallography (SFX) with an X-ray free-electron laser is used for the structural determination of proteins from a large number of microcrystals at room temperature. To examine the feasibility of pharmaceutical applications of SFX, a ligand-soaking experiment using thermolysin microcrystals has been performed using SFX. The results were compared with those from a conventional experiment with synchrotron radiation (SR) at 100 K. A protein–ligand complex structure was successfully obtained from an SFX experiment using microcrystals soaked with a small-molecule ligand; both oil-based and water-based crystal carriers gave essentially the same results. In a comparison of the SFX and SR structures, clear differences were observed in the unit-cell parameters, in the alternate conformation of side chains, in the degree of water coordination and in the ligand-binding mode.

scholarly journals Comparison of NDE Results and Correlation With Microstructural Characteristics of NiFeAl/Wf

1994 ◽  
Author(s):  
David K. Hsu ◽  
Peter K. Liaw ◽  
George Y. Baaklini
Keyword(s):  
Quality Assurance ◽  
Nondestructive Evaluation ◽  
Metal Matrix ◽  
Complex Structure ◽  
Matrix Composites ◽  
Fiber Density ◽  
Microstructural Characteristics ◽  
X Ray ◽  
Intermetallic Matrix ◽  
Intermetallic Matrix Composites

Metal matrix composites (MMC) and intermetallic matrix composites (IMC) are materials of complex structure. Nominally defect-free, as-manufactured MMC requires nondestructive evaluation (NDE) for quality assurance and process monitoring purposes. In this work, three NDE techniques — ultrasonics, eddy current, and X-ray radiography — were applied to un-damaged NiFeAI/Wf coupons. Images of the coupons were obtained using the three techniques. The NDE results were compared among themselves, and correlations were sought between these results and microstructural features of the specimen. Consistencies were found among the NDE results and a strong correlation was found between the spatial variation of fiber density and the NDE signals.

scholarly journals Preliminary joint X-ray and neutron protein crystallographic studies of ecDHFR complexed with folate and NADP+

2014 ◽  
Vol 70 (6) ◽  
pp. 814-818 ◽  
Author(s):  
Qun Wan ◽  
Andrey Y. Kovalevsky ◽  
Mark A. Wilson ◽  
Brad C. Bennett ◽  
Paul Langan ◽  
...  
Keyword(s):  
Dihydrofolate Reductase ◽  
Ternary Complex ◽  
Room Temperature ◽  
Catalytic Mechanism ◽  
National Laboratory ◽  
Complex Structure ◽  
Protonation State ◽  
Data Set ◽  
X Ray ◽  
Oak Ridge

A crystal ofEscherichia colidihydrofolate reductase (ecDHFR) complexed with folate and NADP+of 4 × 1.3 × 0.7 mm (3.6 mm3) in size was obtained by sequential application of microseeding and macroseeding. A neutron diffraction data set was collected to 2.0 Å resolution using the IMAGINE diffractometer at the High Flux Isotope Reactor within Oak Ridge National Laboratory. A 1.6 Å resolution X-ray data set was also collected from a smaller crystal at room temperature. The neutron and X-ray data were used together for joint refinement of the ecDHFR–folate–NADP+ternary-complex structure in order to examine the protonation state, protein dynamics and solvent structure of the complex, furthering understanding of the catalytic mechanism.

Development of a neonate X‐ray phantom for 2D imaging applications using single‐tone inkjet printing

2021 ◽  
Author(s):  
Juan P. Cruz‐Bastida ◽  
Emily L. Marshall ◽  
Nikolaj Reiser ◽  
Jonathan George ◽  
Erik A. Pearson ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
Single Tone ◽  
X Ray ◽  
2D Imaging

scholarly journals An Archaeometallurgical Investigation on Metal Samples from the Chiaravalle Cross

Heritage ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 836-847 ◽  
Author(s):  
Daniela Di Martino ◽  
Enrico Perelli Cippo ◽  
Antonella Scherillo ◽  
Zsolt Kasztovszky ◽  
Ildikó Harsányi ◽  
...  
Keyword(s):  
Activation Analysis ◽  
Complex Structure ◽  
Unknown Origin ◽  
Mineralogical Composition ◽  
Prompt Gamma Activation Analysis ◽  
Prompt Gamma ◽  
13Th Century ◽  
Gamma Activation ◽  
X Ray ◽  
Manufacturing Techniques

The production and manufacturing techniques of metals involve expertise, and the study of ancient artifacts relies on interdisciplinary skills. Metalworking processes used in the production of jewelry masterpieces can, for example, give indications on the provenance of an ancient object of an unknown origin and the techniques used. In this regard, metallic samples from the Chiaravalle Cross (a beautiful processional cross with a complex structure, dating to the 13th century) have been studied, combining bulk and point measurements. Neutron-based experiments (like Prompt Gamma Activation Analysis and neutron diffraction) provide the bulk of the elemental and mineralogical composition, while particle induced X-ray emission analyses evidenced important details on its manufacturing techniques.

scholarly journals X-ray crystallographic studies of the middle part of the human synaptonemal complex protein 1 coiled-coil domain

2015 ◽  
Vol 71 (9) ◽  
pp. 1131-1134 ◽  
Author(s):  
Hyun Ho Park
Keyword(s):  
Synaptonemal Complex ◽  
Short Form ◽  
Complex Structure ◽  
Coiled Coil ◽  
Middle Part ◽  
X Ray ◽  
Cell Parameters ◽  
Coiled Coil Domain ◽  
Complex Protein ◽  
Synaptonemal Complex Protein

The synaptonemal complex is a meiosis-specific complex structure formed at the synapse of homologous chromosomes to hold them together during meiosis. Synaptonemal complex protein 1 (SYCP1) is one of the components of the syneptonemal complex. In this study, the short form of the coiled-coil domain of SYCP1 was overexpressed inEscherichia coliwith an engineered C-terminal His tag. The short form of the coiled-coil domain of SYCP1 was then purified to homogeneity and crystallized at 293 K. X-ray diffraction data were collected to a resolution of 3.0 Å from a crystal belonging to space groupI4, with unit-cell parametersa= 41.95,b= 41.95,c= 318.78 Å. The asymmetric unit was estimated to contain two molecules.

Nasal Anatomy and Function

2017 ◽  
Vol 33 (01) ◽  
pp. 003-008 ◽  
Author(s):  
Ruchin Patel
Keyword(s):  
Complex Structure ◽  
Respiratory Physiology ◽  
Nasal Reconstruction ◽  
Facial Aesthetics ◽  
Basic Understanding ◽  
Nasal Anatomy ◽  
And Function ◽  
Nasal Function ◽  
Nasal Defects

AbstractThe nose is a complex structure important in facial aesthetics and in respiratory physiology. Nasal defects can pose a challenge to reconstructive surgeons who must re-create nasal symmetry while maintaining nasal function. A basic understanding of the underlying nasal anatomy is thus necessary for successful nasal reconstruction.

The Occurrence of Polymely and Polydactyly in Natural Populations of Anurans of the USSR

1986 ◽  
Vol 7 (3) ◽  
pp. 205-216 ◽  
Author(s):  
Leo J. Borkin ◽  
M.M. Pikulik
Keyword(s):  
Natural Populations ◽  
Rana Esculenta ◽  
Bufo Bufo ◽  
Species Specificity ◽  
Rana Arvalis ◽  
X Ray ◽  
Toad Bufo ◽  
Toad Bufo Bufo ◽  
Rana Lessonae ◽  
Ussr Fauna

AbstractVarious cases of isolated and mass polymely and polydactyly in anurans of the USSR fauna are summarized. Mass polydactylies in frogs Rana arvalis arvalis and Rana lessonae-Rana esculenta as well as in toad Bufo bufo bufo are reported. Classiication of polydactyly types based on X-ray analysis is proposed. Species-specificity and lozalized appearance of mass polydactyly factor(s) are discussed.

scholarly journals Blowhole Detection Based on Bidirectional Enhancement and Omnidirectional Analysis for X-Ray Inspection of Castings

2019 ◽  
Vol 2019 ◽  
pp. 1-16
Author(s):  
Xinyue Zhao ◽  
Jingjing Liang ◽  
Zaixing He ◽  
Shuyou Zhang
Keyword(s):  
3D Model ◽  
Detection Method ◽  
Complex Structure ◽  
Model Fitting ◽  
Extraction Process ◽  
Experimental Results ◽  
Defect Region ◽  
Defect Identification ◽  
X Ray ◽  
Identification Process

Small blurred blowholes are difficult to detect, especially those in castings having a complex structure. In this paper, we propose a blowhole detection method based on bidirectional enhancement and omnidirectional analysis for X-ray inspection of castings. After obtaining the X-ray images of a casting from the X-ray inspection equipment, there are two main processes to detect the blowholes. First, in the extraction process for the potential defect region, we propose a method based on bidirectional enhancement that highlights the blurred defects and models the nondefective structure. Second, in the precise defect identification process, we propose a method to distinguish real defects by 3D model fitting-based omnidirectional analysis. The experimental results indicate that the proposed method has a higher performance in blowhole detection than comparable methods.

scholarly journals Functionalized 1,3-Thiazolidin-4-Ones from 2-Oxo-Acenaphthoquinylidene- and [2.2]Paracyclophanylidene-Thiosemicarbazones

Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3069 ◽  
Author(s):  
Ashraf A. Aly ◽  
Nasr K. Mohamed ◽  
Alaa A. Hassan ◽  
Kamal M. El-Shaieb ◽  
Maysa M. Makhlouf ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Spectroscopic Data ◽  
Complex Structure ◽  
2D Nmr ◽  
Efficient Tool ◽  
X Ray ◽  
Dialkyl Acetylenedicarboxylates ◽  
Allyl Derivative

The reactions of dialkyl acetylenedicarboxylates with various 2-oxo-acenaphthoquinylidene- and 4-acetyl[2.2]paracyclophanylidene-thiosemicarbazones were investigated. Using simple experimental procedures, 1,3-Thiazolidin-4-ones derived from acenaphthequinone or [2.2]paracyclophane were obtained as major products in good yields. In the case of allyl derivative of acenaphthoquinylidene-thiosemicarbazones, a complex structure of tetramethyl 5-(2-(((Z,E)-N-allyl-N′-(2-oxoacenaphthylen-1(2H)-ylidene)carbamohydrazonoyl)thio)-1,2,3-tris-(methoxycarbonyl)-cyclopropyl)-4-methoxy-7-oxabicyclo[2.2.1]hepta-2,5-diene-1,2,3,6-tetracarboxylate was formed. Single crystal X-ray analysis was used as an efficient tool to confirm the structure of the synthesized compounds as well as different spectroscopic data (1H-NMR, 13C-NMR, 2D-NMR, mass spectrometry and elemental analysis). The mechanism of the obtained products was discussed.

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