A study of the Willgerodt–Kindler reaction to obtain thioamides and α-ketothioamides under solvent-less conditions

2012 ◽  
Vol 90 (7) ◽  
pp. 567-573 ◽  
Author(s):  
José Ernesto Valdez-Rojas ◽  
Hulme Ríos-Guerra ◽  
Alma Leticia Ramírez-Sánchez ◽  
Guadalupe García-González ◽  
Cecilio Álvarez-Toledano ◽  
...  
Keyword(s):  
Solvent Free ◽  
First Time ◽  
Better Than

In this paper, the results obtained in the synthesis of thioamides and α-ketothioamides by a modification of the Willgerodt–Kindler reaction, under solvent-free and noncatalyst conditions using IR energy as a source of activation, are presented. The use of IR energy in these reactions has been shown to lead to a mixture of thioamide and α-ketothioamide as the main products in most cases, with the latter predominating. The yields of α-ketothioamides from most of these reactions are better than those reported previously. To the best of our knowledge, this is the first time that IR energy has been applied to promote the Willgerodt–Kindler reaction.

scholarly journals Effect of Antibacterial Root Canal Sealer on Persistent Apical Periodontitis

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 741
Author(s):  
Zheng Wang ◽  
Ge Yang ◽  
Biao Ren ◽  
Yuan Gao ◽  
Xian Peng ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Therapeutic Effect ◽  
Root Canal ◽  
Apical Periodontitis ◽  
Control Group ◽  
Root Canal Sealer ◽  
Root Canal Filling ◽  
First Time ◽  
Cone Beam Computer Tomography ◽  
Better Than

The infection of Enterococcus faecalis and its interacting microorganisms in the root canal could cause persistent apical periodontitis (AP). Antibacterial root canal sealer has favorable prospects to inhibit biofilms. The purpose of this study was to investigated the antibacterial effect of root canal sealer containing dimethylaminododecyl methacrylate (DMADDM) on persistent AP in beagle dogs for the first time. Persistent AP was established by a two-step infection with Enterococcus faecalis and multi-bacteria (Enterococcus faecalis, Lactobacillus acidophilus, Actinomycesnaeslundii, Streptococcus gordonii). Root canal sealer containing DMADDM (0%, 1.25%, 2.5%) was used to complete root canal filling. The volume of lesions and inflammatory grade in the apical area were evaluated by cone beam computer tomography (CBCT) and hematoxylin-eosin staining. Both Enterococcus-faecalis- and multi-bacteria-induced persistent AP caused severe apical destruction, and there were no significant differences in pathogenicity between them. DMADDM-modified sealer significantly reduced the volume of periapical lesion and inflammatory grade compared with the control group, among them, the therapeutic effect of the 2.5% group was better than the 1.25% group. In addition, E.faecalis-induced reinfection was more sensitive to the 2.5% group than multi-bacteria reinfection. This study shows that root canal sealer containing DMADDM had a remarkable therapeutic effect on persistent AP, especially on E. faecalis-induced reinfection.

scholarly journals Solvent-Free Processing of Drug-Loaded Poly(ε-Caprolactone) Scaffolds with Tunable Macroporosity by Combination of Supercritical Foaming and Thermal Porogen Leaching

Polymers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 159
Author(s):  
Víctor Santos-Rosales ◽  
Inés Ardao ◽  
Leticia Goimil ◽  
Jose Luis Gomez-Amoza ◽  
Carlos A. García-González
Keyword(s):  
Bone Repair ◽  
Drug Loading ◽  
Ammonium Bicarbonate ◽  
Bone Diseases ◽  
Solvent Free ◽  
Bone Integration ◽  
Bioactive Agents ◽  
First Time ◽  
Supercritical Foaming ◽  
Foaming Technology

Demand of scaffolds for hard tissue repair increases due to a higher incidence of fractures related to accidents and bone-diseases that are linked to the ageing of the population. Namely, scaffolds loaded with bioactive agents can facilitate the bone repair by favoring the bone integration and avoiding post-grafting complications. Supercritical (sc-)foaming technology emerges as a unique solvent-free approach for the processing of drug-loadenu7d scaffolds at high incorporation yields. In this work, medicated poly(ε-caprolactone) (PCL) scaffolds were prepared by sc-foaming coupled with a leaching process to overcome problems of pore size tuning of the sc-foaming technique. The removal of the solid porogen (BA, ammonium bicarbonate) was carried out by a thermal leaching taking place at 37 °C and in the absence of solvents for the first time. Macroporous scaffolds with dual porosity (50–100 µm and 200–400 µm ranges) were obtained and with a porous structure directly dependent on the porogen content used. The processing of ketoprofen-loaded scaffolds using BA porogen resulted in drug loading yields close to 100% and influenced its release profile from the PCL matrix to a relevant clinical scenario. A novel solvent-free strategy has been set to integrate the incorporation of solid porogens in the sc-foaming of medicated scaffolds.

scholarly journals CPC2 Reduction with Hipparcos and Proper Motions in The Southern Hemisphere

1998 ◽  
Vol 11 (1) ◽  
pp. 551-551
Author(s):  
N. Zacharias ◽  
M.I. Zacharias ◽  
C. de Vegt ◽  
C.A. Murray
Keyword(s):  
Southern Hemisphere ◽  
Systematic Errors ◽  
Reference Star ◽  
Proper Motions ◽  
Positional Accuracy ◽  
Star Catalog ◽  
Naval Observatory ◽  
Celestial Reference System ◽  
First Time ◽  
Better Than

The Second Cape Photographic Catalog (CPC2) contains 276,131 stars covering the entire Southern Hemisphere in a 4-fold overlap pattern. Its mean epoch is 1968, which makes it a key catalog for proper motions. A new reduction of the 5687 plates using on average 40 Hipparcos stars per plate has resulted in a vastly improved catalog with a positional accuracy of about 40 mas (median value) per coordinate, which comes very close to the measuring precision. In particular, for the first time systematic errors depending on magnitude and color can be solved unambiguously and have been removed from the catalog. In combination with the Tycho Catalogue (mean epoch 1991.25) and the upcoming U.S. Naval Observatory CCD Astrograph Catalog (UCAC) project proper motions better than 2 mas/yr can be obtained. This will lead to a vastly improved reference star catalog in the Southern Hemisphere for the final Astrographic Catalogue (AC) reductions, which will then provide propermotions for millions of stars when combined with new epoch data. These data then will allow an uncompromised reduction of the southern Schmidt surveys on the International Celestial Reference System (ICRS).

scholarly journals Investigation of Solubility Behavior of Canagliflozin Hydrate Crystals Combining Crystallographic and Hirshfeld Surface Calculations

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 298
Author(s):  
Yefen Zhu ◽  
Yanlei Kang ◽  
Ling Zhu ◽  
Kaxi Yu ◽  
Shuai Chen ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Intermolecular Forces ◽  
Hirshfeld Surface ◽  
Reversible Inhibitor ◽  
Solubility Behavior ◽  
Hydrogen Bond Networks ◽  
Solvent Molecules ◽  
First Time ◽  
Better Than

Canagliflozin (CG) was a highly effective, selective and reversible inhibitor of sodium-dependent glucose co-transporter 2 developed for the treatment of type 2 diabetes mellitus. The crystal structure of CG monohydrate (CG-H2O) was reported for the first time while CG hemihydrate (CG-Hemi) had been reported in our previous research. Solubility and dissolution rate results showed that the solubility of CG-Hemi was 1.4 times higher than that of CG-H2O in water and hydrochloric acid solution, and the dissolution rates of CG-Hemi were more than 3 folds than CG-H2O in both solutions. Hirshfeld surface analysis showed that CG-H2O had stronger intermolecular forces than CG-Hemi, and water molecules in CG-H2O participated three hydrogen bonds, forming hydrogen bond networks. These crystal structure features might make it more difficult for solvent molecules to dissolve CG-H2O than CG-Hemi. All these analyses might explain why the dissolution performance of CG-Hemi was better than CG-H2O. This work provided an approach to predict the dissolution performance of the drug based on its crystal structure.

Research of the Workpiece-Stage Control System Based on the ACR9000 in the Composite Coating Equipment of MEVVAII and FAD

2013 ◽  
Vol 668 ◽  
pp. 410-414
Author(s):  
Rui Xia Zhang ◽  
Bin Liao ◽  
Zhi Guo Liu ◽  
Xian Ying Wu
Keyword(s):  
Control System ◽  
Servo Control ◽  
Uniform Rotation ◽  
Coating Films ◽  
Servo Control System ◽  
Motion Modes ◽  
Speed Rotation ◽  
Micro Tools ◽  
First Time ◽  
Better Than

In order to realize the extensive application of technologies of MEVVAII and FAD, the composite equipment has been developed for surface modification and coating films. In this paper, for the first time, the servo control system based on ACR9000 has been used to control workpiece-stage of the composite equipment. Eight target disks are installed on workpiece-stage. Each of target disks can be mounted about 1300 PCB micro tools. So, the equipment can satisfy the requirement for mass production. Experimental results show that the coating unevenness is less than ±14%, better than those of traditional equipments which is less than ±29%. The main purpose of the paper is to introduce the design of workpiece-stage and its three motion modes of rotary positioning, uniform rotation and variable speed rotation, and coating effects corresponding to three motion modes have been verified by experiments.

Sustainable Passerini-tetrazole three component reaction (PT-3CR): selective synthesis of oxaborol-tetrazoles

2021 ◽  
Vol 57 (76) ◽  
pp. 9708-9711
Author(s):  
Akansha Singh ◽  
Ravindra Kumar
Keyword(s):  
Solvent Free ◽  
Selective Synthesis ◽  
Three Component Reaction ◽  
First Time

A sustainable catalyst- and solvent-free Passerini-tetrazole three component reaction (PT-3CR) has been developed for the selective synthesis of benzoxaborol-tetrazoles for the first time.

scholarly journals Low-temperature and purification-free stereocontrolled ring-opening polymerisation of lactide in supercritical carbon dioxide

2020 ◽  
Vol 22 (7) ◽  
pp. 2197-2202 ◽  
Author(s):  
Simon P. Bassett ◽  
Andrew D. Russell ◽  
Paul McKeown ◽  
Isabel Robinson ◽  
Thomas R. Forder ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Supercritical Carbon Dioxide ◽  
Ring Opening ◽  
Solvent Free ◽  
Free Ring ◽  
First Time ◽  
Supercritical Carbon

A stereoselective, solvent-free ring-opening polymerisation (ROP) of lactide (LA) in supercritical carbon dioxide (scCO2) is reported for the first time.

scholarly journals Application Research of Perioperative Clinical Pathway Based on Accelerated Rehabilitation Surgery Strategy in Patients with ERCP

2021 ◽  
Vol 5 (4) ◽  
pp. 113-118
Author(s):  
Xing Yang
Keyword(s):  
Clinical Pathway ◽  
Reference Group ◽  
Anxiety And Depression ◽  
Study Group ◽  
Application Research ◽  
Clinical Nursing ◽  
Accelerated Rehabilitation ◽  
Postoperative Time ◽  
First Time ◽  
Better Than

Objective: To explore the effects of perioperative clinical pathway of accelerated rehabilitation surgery strategy in patients undergoing cholangiopancreatography (ERCP). Methods: Randomly selected 40 patients undergoing ERCP from our hospital which is People’s Hospital, Jingjiang City, for research, and divided the patients into two groups. The 20 patients who were given conventional education methods were set as the reference group, and the 20 patients who were given perioperative clinical pathway care with accelerated rehabilitation surgery strategies were the research group, where the clinical nursing effect of the two groups was statistically compared. Results: According to clinical observation and statistics, the study group’s postoperative time to eat for the first time, time to get out of bed, hospitalization time, and surgical blood loss were better than those of the reference group, P<0.05; the anxiety and depression scores of the study group were lower than those after nursing in the reference group, P<0.05; the incidence of complications in the study group was lower than that in the reference group, and patient satisfaction was higher than that in the reference group, where both P<0.05. Conclusion: The application of perioperative clinical pathway care based on the strategy of accelerated rehabilitation surgery can achieve significant results in ERCP patients, which can effectively improve the surgical indicators of patients and reduce the risk of complications.

scholarly journals Testing and Development of Transfer Functions for Weighing Precipitation Gauges in WMO-SPICE

2017 ◽  
Author(s):  
John Kochendorfer ◽  
Rodica Nitu ◽  
Mareile Wolff ◽  
Eva Mekis ◽  
Roy Rasmussen ◽  
...  
Keyword(s):  
Transfer Functions ◽  
Precipitation Amount ◽  
Wind Speeds ◽  
Small Manufacturer ◽  
Lower Porosity ◽  
Precipitation Gauge ◽  
Reference Amount ◽  
First Time ◽  
High Winds ◽  
Better Than

Abstract. Adjustments for the undercatch of solid precipitation caused by wind were developed for different weighing gauge/wind shield combinations tested in WMO-SPICE. These include several different manufacturer-provided unshielded and single-Alter shielded weighing gauges, a MRW500 precipitation gauge within a small, manufacturer-provided shield, and host-provided precipitation gauges within double-Alter, Belfort double-Alter, and small Double-Fence Intercomparison Reference (SDFIR) shields. Previously-derived adjustments were also tested on measurements from each weighing gauge/wind shield combination. The transfer functions developed specifically for each of the different types of unshielded and single-Alter shielded weighing gauges did not perform significantly better than the more generic and universal transfer functions developed previously using measurements from eight different WMO-SPICE sites. This indicates that wind shield type (or lack thereof) is more important in determining the magnitude of wind-induced undercatch than the type of weighing precipitation gauge. It also demonstrates the potential for widespread use of the previously-developed, multi-site single-Alter shielded and unshielded transfer functions. In addition, corrections for the lower-porosity Belfort double-Alter shield and a standard double-Alter shield were developed and tested using measurements from two separate sites for the first time. Among all of the manufacturer-provided shields tested, with an average undercatch of about 5 %, the Belfort double Alter shield required the least amount of correction, and caught ~ 80 % of the reference amount of precipitation even in snowy conditions with wind speeds greater than 5 m  s−1. The SDFIR-shielded gauge accumulated 98 % of the Double-Fence Automated Reference (DFAR) precipitation amount on average, accumulated 90 % of the DFAR accumulation in high winds, and was almost indistinguishable from the full-sized DFAR used as a reference. In general, the more effective wind shields, that were associated with smaller unadjusted errors, also produced more accurate measurements after adjustment.

scholarly journals Very Low Crosstalk Measurement of Substrate Integrated Coaxial Line (SICL)

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1174
Author(s):  
Lu ◽  
Yang ◽  
Yin ◽  
Zhao ◽  
Liu
Keyword(s):  
Coplanar Waveguide ◽  
Reference Value ◽  
Coaxial Line ◽  
Calculation Formula ◽  
Frequency Range ◽  
Practical Design ◽  
Measured Frequency Range ◽  
Coaxial Lines ◽  
First Time ◽  
Better Than

When designing a microwave circuit involving substrate integrated coaxial lines (SICLs), it is important to know what real crosstalk between SICLs is. A measured crosstalk will be a good reference value in a practical design. In addition, it is also needed to compare and check the crosstalk from the simulation and calculation formula with measured results. However, it is very difficult to measure the crosstalk between SICLs because it is theoretically very low. In this study, for the first time, the crosstalk characteristics of a SICL are evaluated through experimental design and measurements. By adjusting the layout of the structures and implementing controlled experiments, interference caused by the presence of leaks and radiation at the interface and structural transitions is effectively suppressed. The experimental results show that for two parallel SICLs with a length of 30 mm and an interval of 5 mm, the isolation is greater than 80 dB for the measured frequency range of 1–8 GHz, significantly better than the results of the grounded coplanar waveguide (GCPW).

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