The crystal and molecular structure of thioformaldehyde trimer

1967 ◽  
Vol 45 (4) ◽  
pp. 353-357 ◽  
Author(s):  
J. E. Fleming ◽  
H. Lynton
Keyword(s):  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Bond Distance ◽  
Orthorhombic Space Group ◽  
Significant Difference ◽  
The Mean ◽  
Temperature Factors ◽  
No Absorption ◽  
Good Agreement ◽  
Atomic Parameters

Crystals of thioformaldehyde trimer, (CH2S)3 are orthorhombic, space group Pmn21 with a = 7.697 Å [Formula: see text], b = 7.067 Å [Formula: see text], c = 5.323 Å [Formula: see text]. There are two molecules in the unit cell with sulfur and carbon atoms in positions (4b) and (2a). The atomic parameters for sulfur and carbon have been determined from a three-dimensional analysis using observed and calculated differential syntheses with isotropic temperature factors. No absorption corrections were applied to the intensity data and no attempt has been made to establish the hydrogen positions. The final discrepancy index is R = 0.093. The molecule has the chair configuration and shows no significant difference between the lengths of any S—C bonds. The mean S—C bond distance is 1.818 Å and the standard deviation of the mean is 0.003 Å. This value is in good agreement with the commonly accepted value of 1.817 ± 0.005 Å for the S—C paraffinic bond.

Crystal and molecular structure of the pyridine solvate of bis(8-hydroxyquinoline)silver(I)

1968 ◽  
Vol 46 (4) ◽  
pp. 471-477 ◽  
Author(s):  
J. E. Fleming ◽  
H. Lynton
Keyword(s):  
Silver Atom ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Monoclinic Space Group ◽  
Phenolic Oxygen ◽  
Cell Dimensions ◽  
Ring Nitrogen ◽  
Temperature Factors ◽  
No Absorption ◽  
Atomic Parameters

Crystals of the pyridine solvate of bis(8-hydroxyquinoline)silver(I), Ag(C9H9NO)C9H6NOHO•C5H5N, are monoclinic, space group P21/a, with cell dimensions a = 10.87 ± 0.01 Å, b = 10.65 ± 0.01 Å, c = 16.70 ± 0.01 Å, β = 92.6 ± 0.2°, Z = 4. Atomic parameters have been determined from a three-dimensional analysis using 2163 independent intensities to which no absorption corrections were applied. Refinement was by observed and calculated differential syntheses using isotropic temperature factors. The final discrepancy index is R = 0.116.The coordination of the silver atom is distorted tetrahedral, with bonds to the phenolic oxygen and ring nitrogen atoms of both 8-hydroxyquinoline molecules. Adjacent bis(8-hydroxyquinoline)silver molecules are linked by a hydrogen bond between two oxygen atoms. The pyridine molecules are held in the lattice by van der Waals' forces.

The Crystal and Molecular Structure of 3-Chloro-3-deoxy-1,2;5,6-di-O-isopropylidene-β-D-idose

1972 ◽  
Vol 50 (1) ◽  
pp. 93-98 ◽  
Author(s):  
F. W. B. Einstein ◽  
K. N. Slessor
Keyword(s):  
Molecular Structure ◽  
Furan Ring ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
R Factor ◽  
A Cell ◽  
The Mean ◽  
Least Squares Techniques

The crystal and molecular structure of 3-chloro-3-deoxy-1,2;5,6-di-O-isopropylidene-β-D-idose has been determined from three dimensional X-ray data collected by counter methods. The structure was refined by full-matrix least-squares techniques to a conventional R factor of 5.7% for the 817 observed reflections. The compound crystallizes in the orthorhombic space group P212121 with four molecules in a cell of dimensions a = 9.744(6), b = 26.76(2), c = 5.403(3) Å.The structure analysis has served to confirm the site of halogenation and that it occurs stereospecifically. The conformation of the furan ring is an envelope arrangement with C(4) displaced from the mean plane.

Evaluating the Effect of Three-Dimensional Visualization on Force Application and Performance Time during Robotics-Assisted Mitral Valve Repair

2013 ◽  
Vol 8 (3) ◽  
pp. 199-205 ◽  
Author(s):  
Maria E. Currie ◽  
Ana Luisa Trejos ◽  
Reiza Rayman ◽  
Michael W.A. Chu ◽  
Rajni Patel ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Mitral Valve ◽  
Haptic Feedback ◽  
3D Visualization ◽  
Three Dimensional ◽  
Test Bed ◽  
Mitral Valve Annuloplasty ◽  
Significant Difference ◽  
The Mean ◽  
Mean Time

Objective The purpose of this study was to determine the effect of three-dimensional (3D) binocular, stereoscopic, and two-dimensional (2D) monocular visualization on robotics-assisted mitral valve annuloplasty versus conventional techniques in an ex vivo animal model. In addition, we sought to determine whether these effects were consistent between novices and experts in robotics-assisted cardiac surgery. Methods A cardiac surgery test-bed was constructed to measure forces applied during mitral valve annuloplasty. Sutures were passed through the porcine mitral valve annulus by the participants with different levels of experience in robotics-assisted surgery and tied in place using both robotics-assisted and conventional surgery techniques. Results The mean time for both the experts and the novices using 3D visualization was significantly less than that required using 2D vision (P < 0.001). However, there was no significant difference in the maximum force applied by the novices to the mitral valve during suturing (P = 0.7) and suture tying (P = 0.6) using either 2D or 3D visualization. The mean time required and forces applied by both the experts and the novices were significantly less using the conventional surgical technique than when using the robotic system with either 2D or 3D vision (P < 0.001). Conclusions Despite high-quality binocular images, both the experts and the novices applied significantly more force to the cardiac tissue during 3D robotics-assisted mitral valve annuloplasty than during conventional open mitral valve annuloplasty. This finding suggests that 3D visualization does not fully compensate for the absence of haptic feedback in robotics-assisted cardiac surgery.

scholarly journals Water vapor observations up to the lower stratosphere through the Raman lidar during the MAïdo LIdar Calibration Campaign

2014 ◽  
Vol 7 (10) ◽  
pp. 10361-10422
Author(s):  
D. Dionisi ◽  
P. Keckhut ◽  
Y. Courcoux ◽  
A. Hauchecorne ◽  
J. Porteneuve ◽  
...  
Keyword(s):  
Water Vapor ◽  
Calibration Procedure ◽  
Relative Difference ◽  
Lamp Method ◽  
Control Procedure ◽  
Significant Difference ◽  
The Mean ◽  
Set Up ◽  
Lidar Calibration ◽  
Good Agreement

Abstract. A new lidar system devoted to tropospheric and lower stratospheric water vapor measurements has been installed at the Maïdo altitude station facility of La Reunion Island, in the southern subtropics. The main objectives of the MAïdo LIdar Calibration Campaign (MALICCA), performed in April 2013, were to validate the system, to set up a calibration methodology, to compare the acquired water profiles with radiosonde measurements and to evaluate its performances and capabilities with a particular focus on the UTLS measurements. Varying the characteristics of the transmitter and the receiver components, different system configuration scenarios were tested and possible parasite signals (fluorescent contamination, rejection) were investigated. A hybrid calibration methodology has been set up and validated to insure optimal lidar calibration stability with time. In particular, the receiver transmittance is monitored through the calibration lamp method that, at the moment, can detect transmittance variations greater than 10–15%. Calibration coefficients are then calculated through the hourly values of IWV provided by the co-located GPS. The comparison between the constants derived by GPS and Vaisala RS92 radiosondes launched at Maïdo during MALICCA, points out an acceptable agreement in terms of accuracy of the mean calibration value (with a difference of approximately 2–3%), but a significant difference in terms of variability (14 vs. 7–9%, for GPS and RS92 calibration procedures, respectively). We obtained a relatively good agreement between the lidar measurements and 15 co-located and simultaneous RS92 radiosondes. A relative difference below 10% is measured in low and middle troposphere (2–10 km). The upper troposphere (up to 15 km) is characterized by a larger spread (approximately 20%), because of the increasing distance between the two sensors. To measure water vapor in the UTLS region, nighttime and monthly water vapor profiles are presented and compared. The good agreement between the lidar monthly profile and the mean WVMR profile measured by satellite MLS has been used as a quality control procedure of the lidar product, attesting the absence of significant wet biases and validating the calibration procedure. Thanks to its performance and location, the MAIDO H2O lidar is devoted to become a reference instrument in the southern subtropics, allowing to insure the long-term survey of the vertical distribution of water vapor, and to document scientific themes such as stratosphere–troposphere exchange, tropospheric dynamics in the subtropics, links between cirrus clouds and water vapor.

scholarly journals Anatomical Study of the Clavicles in a Chinese Population

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xu-sheng Qiu ◽  
Xiao-bo Wang ◽  
Yan Zhang ◽  
Yan-Cheng Zhu ◽  
Xia Guo ◽  
...  
Keyword(s):  
Chinese Population ◽  
Three Dimensional ◽  
Anatomical Study ◽  
Anatomical Studies ◽  
Intramedullary Canal ◽  
Significant Difference ◽  
New Development ◽  
Clavicle Fractures ◽  
The Mean ◽  
Two Sides

Background. A reemergence of interest in clavicle anatomy was prompted because of the advocacy for operative treatment of midshaft clavicle fractures. Several anatomical studies of the clavicle have been performed in western population. However, there was no anatomical study of clavicle in Chinese population.Patients and Methods. 52 patients were included in the present study. Three-dimensional reconstructions of the clavicles were generated. The length of the clavicle, the widths and thicknesses of the clavicle, curvatures of the clavicle, the areas of the intramedullary canal, and sectional areas of the clavicle were measured. All the measurements were compared between genders and two sides.Results. The mean length of the clavicles was144.2±12.0 mm. Clavicles in males were longer, wider, and thicker than in females; also males have different curvatures in both planes compared with females. The men’s intramedullary canals and sectional areas of the clavicle were larger than those of women. No significant difference between the sides was found for all the measurements.Conclusion. This study provided an anatomical data of the clavicle in a Chinese population. These clavicle dimensions can be applied to the modifications of the contemporary clavicle plate or a new development for the Chinese population.

scholarly journals Crystal structure of 1-[(2S*,4R*)-6-fluoro-2-methyl-1,2,3,4-tetrahydroquinolin-4-yl]pyrrolidin-2-one

2014 ◽  
Vol 70 (9) ◽  
pp. 153-156
Author(s):  
P. S. Pradeep ◽  
S. Naveen ◽  
M. N. Kumara ◽  
K. M. Mahadevan ◽  
N. K. Lokanath
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Bond Distance ◽  
Chair Conformation ◽  
Dimensional Structure ◽  
Pyrrolidine Ring ◽  
Charge Delocalization ◽  
Compound C ◽  
The Mean ◽  
Bond Character

In the title compound, C14H17FN2O, the 1,2,3,4-tetrahydropyridine ring of the quinoline moiety adopts a half-chair conformation, while the pyrrolidine ring has an envelope conformation with the central methylene C atom as the flap. The pyrrolidine ring lies in the equatorial plane and its mean plane is normal to the mean plane of the quinoline ring system, with a dihedral angle value of 88.37 (9)°. The bridging N—C bond distance [1.349 (3) Å] is substantially shorter than the sum of the covalent radii (dcov: C—N = 1.47 Å and C=N = 1.27 Å), which indicates partial double-bond character for this bond, resulting in a certain degree of charge delocalization. In the crystal, molecules are linked by N—H...O and C—H...O hydrogen bonds, forming sheets lying parallel to (10-1). These two-dimensional networks are linkedviaC—H...F hydrogen bonds and C—H...π interactions, forming a three-dimensional structure.

Relocation of Papillary Muscles for Ischemic Mitral Valve Regurgitation

2014 ◽  
Vol 9 (1) ◽  
pp. 54-59 ◽  
Author(s):  
Khalil Fattouch ◽  
Sebastiano Castrovinci ◽  
Giacomo Murana ◽  
Pietro Dioguardi ◽  
Francesco Guccione ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Mitral Valve Repair ◽  
Geometric Model ◽  
Three Dimensional ◽  
Mitral Valve Regurgitation ◽  
Papillary Muscles ◽  
Valve Repair ◽  
Truncated Cone ◽  
Significant Difference ◽  
The Mean

Objective The assessment of the mitral valve apparatus (MVA) and its modifications during ischemic mitral regurgitation (IMR) is better performed by three-dimensional (3D) transesophageal echocardiography (TEE). The aim of our study was to carry out nonrestrictive mitral annuloplasty in addition to relocation of papillary muscles (PPMs) oriented by preoperative real-time 3D TEE through the mitral valve quantification dedicated software. Methods Since January 2008, a total of 70 patients with severe IMR were examined both before and after mitral valve repair. The mean (SD) coaptation depth and the mean (SD) tenting area were 1.4 (0.4) cm and 3.2 (0.5) cm2, respectively. Intraoperative 3D TEE was performed, followed by a 3D offline reconstruction of the MVA. A schematic MVA model was obtained, and a geometric model as a “truncated cone” was traced according to preoperative data. The expected truncated cone after annuloplasty was retraced. A conventional normal coaptation depth of approximately 6 mm was used to detect the new position of the PPMs tips. Results Perioperative offline reconstruction of the MVA and the respective truncated cone was feasible in all patients. The expected position of the PPMs tips, desirable to reach a normal tenting area with a coaptation depth of 6 mm or more, was obtained in all patients. After surgery, all parameters were calculated, and no statistically significant difference was found compared with the expected data. Conclusions Relocation of PPMs plus ring annuloplasty reduce mitral valve tenting and may improve mitral valve repair results in patients with severe IMR. This technique may be easily and precisely guided by preoperative offline 3D echocardiographic mitral valve reconstruction.

scholarly journals Wits Appraisal of a Qatari Male Population: A Comparative Study. Part II

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Hayder A. Hashim ◽  
Najat Al-Sayed ◽  
Ayah AL-Qaisi
Keyword(s):  
Three Dimensional ◽  
Mean Value ◽  
Cone Beam ◽  
Facial Appearance ◽  
Male Population ◽  
Significant Difference ◽  
The Mean ◽  
Age Range ◽  
Relationship Of ◽  
Gender Specific

Introduction: Cephalometric analysis aims to determine skeletal and dental relationships. The ANB angle, initially suggested by Rediel and applied by Steiner. is the most used angle in establishing the anteroposterior relationship of the mandible to the maxilla. However, limitations to the accuracy of the ANB angle for this purpose have been reported. To avoid these potential sources of inaccuracy a diagnostic tool was introduced by Jenkins and later modified by Jacobson and became known as the “Wits appraisal”. Aims: The aim of this study was to establish the Wits appraisal value in a sample of Qatari males, a group which had not previously been studied in this context, and to compare the findings with those from racially and ethnically differing groups as reported in the literature. Materials and Methods: The sample consisted of 28 lateral cephalometric radiographs of Qatari males with an age range of 15 to 32 years, presenting with a well-balanced facial appearance and an acceptable profile. Results: The mean value of the Wits appraisal for Qatari males in the present study was 0.50 ± 2.96. This differed at a statistically significant level from the mean value in the Jacobson study with no gender significant difference noted. On the other hand, significant differences were found when compared with previous reports on different races. Conclusion: The Wits appraisal value for the Qatari male population studied was 0.5±2.96, a result which is significantly higher than that reported in Jacobson’s study. This study revealed that the Wits appraisal is not ethnicity or gender-specific, and therefore cannot be used to differentiate between different ethnic groups. However, it can find application as an alternative to the ANB angle in the treatment of borderline cases. The application of cone beam computed tomography (CBCT) will enhance the diagnosis and treatment of cases by yielding three-dimensional views.

Three-Dimensional Simulation for Diffusion of Matter in Compound Round Jet by Particle Method

2003 ◽  
Author(s):  
Tomomi Uchiyama ◽  
Akihito Ichikawa
Keyword(s):  
Three Dimensional ◽  
Concentration Field ◽  
Particle Method ◽  
Vortex Method ◽  
Vortical Flow ◽  
Round Jet ◽  
The Mean ◽  
Dimensional Simulation ◽  
Mean Concentration ◽  
Good Agreement

The diffusion of matter in compound round jet is simulated by three-dimensional particle method. The flow field is calculated with a vortex method, whereas the concentration field is simulated through a particle method analogous to the vortex method. It is shown that the concentration distribution yielded by the three-dimensional vortical flow is in good agreement with the experimental one obtained by the flow visualization. The mean concentration is confirmed to be in the self-preservation state.

scholarly journals Comparison of Valgus Correction Angle between Patients with Developmental Dysplasia Hip and Normal Volunteers Measured by Three-Dimensional Reconstruction and X-Ray

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Aobo Zhang ◽  
Qing Han ◽  
Bingpeng Chen ◽  
Chenyu Wang ◽  
Xue Zhao ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Mean Value ◽  
Normal Group ◽  
Correction Angle ◽  
X Ray ◽  
Normal Volunteers ◽  
Significant Difference ◽  
The Mean ◽  
Valgus Correction Angle

Background and purpose. A new method of three-dimensional (3D) reconstruction technology was used to take place of X-ray in measuring valgus correction angle (VCA) of both DDH patients and normal volunteers to improve precision. Two different ways to define VCA according to the various conditions of patients were compared and analyzed. Methods. Bilateral VCA of 50 DDH patients and 56 normal volunteers were measured by Mimics software in the 3D method and X-ray in 2D. Two VCA (the upper VCA and the lower VCA) were measured in both two methods. Every VCA was measured by observer A and observer B for twice separately. The statistical analyses of the differences were calculated among the measurements of the VCA. Results. The mean value of the upper VCA measured in 3D was 4.95°±0.76° in DDH group and 5.56°±0.62° in the normal group with significant difference (t=−6.457, p<0.01). The VCA of DDH group and normal group measured by 3D was larger than 2D, both the upper VCA and the lower VCA. The differences indicated statistically significant. The mean value of lower VCA was 0.60° smaller than the mean value of upper VCA in normal volunteers. The mean value of the lower VCA was 0.58° larger than the mean value of the upper VCA in DDH patients. Conclusions. Compared to X-ray, 3D reconstruction technology is more accurate without conventional limitations. The lower VCA of DDH patients should be regarded as the femoral intramedullary guide angle in TKA, especially for patients with femoral deformities.

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