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AlDabeeb DS, Alakeel NS, Al Jfshar RM, Alkhalid TK. Endocrowns: Indications, Preparation Techniques, and Material Selection. Cureus 2023; 15:e49947. [PMID: 38058523 PMCID: PMC10697178 DOI: 10.7759/cureus.49947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2023] [Indexed: 12/08/2023] Open
Abstract
Endodontic treatment is often necessary in the field of dentistry. As the tooth structure is lost during such treatment, the tooth may become weaker and lose some of its mechanical qualities. Endodontically treated posterior teeth require cuspal coverage because of their anatomical features. Endocrowns are regarded as a suitable choice for restoring teeth that have undergone endodontic treatment. These restorations are recommended when there is a substantial loss of tooth structure, restricted interocclusal space, or a short clinical crown. They are also contraindicated in case of severe loss of tooth structure where adhesion is not applicable. Endocrowns require a specific preparation design that is distinct from the conventional crown. They can be manufactured by two methods: heat pressing or computer-aided design/computer-aided manufacturing (CAD/CAM). Moreover, several materials have been used in fabricating endocrown restoration. Lithium disilicate glass-ceramic is the most recommended material as it possesses excellent mechanical properties and esthetic results with the ability to bond to tooth structure. In conclusion, several kinds of literature recommend using them for molars. Further research is needed to evaluate this technique for premolar and anterior teeth.
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Affiliation(s)
- Dalal S AlDabeeb
- Department of Restorative Dental Sciences, King Saud University, Riyadh, SAU
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Niu H, Zhu Z, Hu D, Ma S, Li R, Yuan S, Ye J, Jin H. [Research and Development Trend of Medical Oxygen Production Equipment]. Zhongguo Yi Liao Qi Xie Za Zhi 2023; 47:294-297. [PMID: 37288631 DOI: 10.3969/j.issn.1671-7104.2023.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Oxygen therapy is an effective clinical method for the treatment of respiratory disorders, oxygen concentrator as a necessary medical auxiliary equipment in hospitals, its research and development has been a hot spot. The study reviewed the development history of the ventilator, introduced the two preparation technique of the oxygen generator pressure swing absorption (PSA) and vacuum pressure swing adsorption (VPSA), and analyzed the core technology development of the oxygen generator. In addition, the study compared some major brands of oxygen concentrators on the market and prospected the development trend of oxygen concentrators.
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Affiliation(s)
- Hangduo Niu
- Shenzhen Key Laboratory for Biomedical Engineering, Shenzhen, 518000
- School of Biomedical Engineering, Health Science center, Shenzhen University, Shenzhen, 518000
| | - Zifu Zhu
- Shenzhen Key Laboratory for Biomedical Engineering, Shenzhen, 518000
- School of Biomedical Engineering, Health Science center, Shenzhen University, Shenzhen, 518000
| | - Dandan Hu
- School of Biological Science and Medical Engineering, Southeast University, Nanjing, 210096
| | - Shengcai Ma
- Shenzhen Key Laboratory for Biomedical Engineering, Shenzhen, 518000
- School of Biomedical Engineering, Health Science center, Shenzhen University, Shenzhen, 518000
| | - Ruowei Li
- Shenzhen Key Laboratory for Biomedical Engineering, Shenzhen, 518000
- School of Biomedical Engineering, Health Science center, Shenzhen University, Shenzhen, 518000
| | - Sinian Yuan
- Shenzhen Key Laboratory for Biomedical Engineering, Shenzhen, 518000
- School of Biomedical Engineering, Health Science center, Shenzhen University, Shenzhen, 518000
| | - Jilun Ye
- Shenzhen Key Laboratory for Biomedical Engineering, Shenzhen, 518000
- School of Biomedical Engineering, Health Science center, Shenzhen University, Shenzhen, 518000
| | - Hao Jin
- Hunan Techray Medical Technology Co. Ltd., Changsha, 410035
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Abstract
The development of orally administered protein drugs is challenging due to their intrinsic unfavourable features, including large molecular size and poor chemical stability, both of which limit gastrointestinal (GI) absorption efficiency. Nanoparticles can overcome the GI barriers effectively and improve the oral bioavailability of proteins in the GI tract. They possess large surface area to volume ratio, and can facilitate the GI absorption of nanoparticles via the paracellular and transcellular routes. Nanoparticles can be prepared by various fabrication techniques that can encapsulate the fragile therapeutic proteins via hydrophobic bonding and electrostatic interaction. A desirable technique should involve minimal harsh conditions and encapsulate therapeutic proteins with preserved functionalities. The current review examines the characteristics of each preparation technique, and illustrates the examples of insulin-loaded nanoparticles that have been developed in each fabrication method. The following techniques, which include nanoprecipitation, hydrophobic conjugation, flash nanocomplexation, double emulsion, ionotropic gelation, and layer-by-layer adsorption, have been used to formulate ligand-modified nanoparticles for targeted delivery of insulin. Other techniques, including reduction, complex coacervation (polyelectrolyte complexation), hydrophobic ion pairing and emulsion solvent diffusion method, and sol-gel technology, were also discussed in the latter part of the review due to their extensive use in fabrication of insulin nanoparticles. This review also discusses the strategies that have been utilised during the formulation process to improve the stability and bioactivity of therapeutic proteins.
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Affiliation(s)
- Chun Y Wong
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Australia.,Curtin Health Innovation Research Institute, Bentley, Australia
| | - Hani Al-Salami
- Biotechnology and Drug Development Research Laboratory, School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Bentley, Australia
| | - Crispin R Dass
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Australia.,Curtin Health Innovation Research Institute, Bentley, Australia
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Chang YR, Liu C, Yin LH. [Research progress on platelet-rich fibrin derivatives]. Hua Xi Kou Qiang Yi Xue Za Zhi 2019; 37:660-665. [PMID: 31875447 DOI: 10.7518/hxkq.2019.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Platelet-rich plasma and platelet-rich fibrin (PRF) are widely used in the field of stomatology. Advance-ments in preparation techniques and basic research have enabled the use of PRF derivatives in oral clinical applications. The evolution, preparation techniques, biological properties, and medical research progress of PRF derivatives are reviewed in this paper.
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Affiliation(s)
- Yao-Ren Chang
- Dept. of Oral Implan-tation, Hospital of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Chun Liu
- Dept. of Oral Implan-tation, Hospital of Stomatology, Lanzhou University, Lanzhou 730000, China
| | - Li-Hua Yin
- Dept. of Oral Implan-tation, Hospital of Stomatology, Lanzhou University, Lanzhou 730000, China;Dept. of Dental Implantation, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
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Schmidt O, Schmidt S, Häuser CL, Hausmann A, Van Vu L. Using Malaise traps for collecting Lepidoptera (Insecta), with notes on the preparation of Macrolepidoptera from ethanol. Biodivers Data J 2019:e32192. [PMID: 30918447 PMCID: PMC6426827 DOI: 10.3897/bdj.7.e32192] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 02/18/2019] [Indexed: 11/12/2022] Open
Abstract
The present paper deals with the potential of employing Malaise traps for collecting butterflies and moths for morphological analysis and presents a protocol for preparing Macrolepidoptera from Malaise trap samples that were preserved in ethanol. About 80 specimens of Lepidoptera, including Nymphalidae, Geometridae, Hesperiidae, Erebidae, Noctuidae, Pyralidae and Tortricidae, were mounted, following the protocol. All specimens with robust wings and contrasting wing patterns were well suited for the study of external morphology, regardless of the family. The specimens used in this study were collected in highland forest areas of central Vietnam with a little known entomofauna, as part of the German-Vietnamese biodiversity project 'VIETBIO'. The study offers new methodological approaches in an attempt to make the most of the material that was obtained using Malaise traps.
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Affiliation(s)
- Olga Schmidt
- SNSB-Zoologische Staatssammlung München, Munich, Germany SNSB-Zoologische Staatssammlung München Munich Germany
| | - Stefan Schmidt
- SNSB-Zoologische Staatssammlung München, Munich, Germany SNSB-Zoologische Staatssammlung München Munich Germany
| | - Christoph L Häuser
- Museum für Naturkunde - Leibniz-Institut für Evolutions-und Biodiversitätsforschung, Berlin, Germany Museum für Naturkunde - Leibniz-Institut für Evolutions-und Biodiversitätsforschung Berlin Germany
| | - Axel Hausmann
- SNSB-Zoologische Staatssammlung München, Munich, Germany SNSB-Zoologische Staatssammlung München Munich Germany
| | - Lien Van Vu
- Vietnam National Museum of Nature, VAST, Hanoi, Vietnam Vietnam National Museum of Nature, VAST Hanoi Vietnam
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Skrzypek TH, Kazimierczak W. A simplified method of preparation of mammalian intestine samples for scanning electron microscopy. Microsc Res Tech 2018; 81:1325-1331. [PMID: 30295361 DOI: 10.1002/jemt.23141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 07/16/2018] [Accepted: 09/04/2018] [Indexed: 11/10/2022]
Abstract
Due to strong tissue hydration and complex architecture of the mucous membrane, appropriate preparation of inhomogeneous gastrointestinal tissues, especially from the intestine, for scanning electron microscopy is still a challenge and requires constant improvement of preparation techniques. In this article, we describe a simplified method of preparation of small intestinal mucosa tissues for observations in a scanning electron microscope. We emphasized the most important points in the preparation process that, when ignored, may result in formation of numerous artifacts and the inability to analyze the samples reliably. The developed technique facilitates proper animal tissue sampling in the field conditions, reducing the time of tissue collection and sample preparation as well as the total process costs. The fixative of choice, that is, buffered formalin, fixes, and stiffens the processed tissues properly, which is especially important in preservation of long, highly hydrated intestinal villi without shrinkage artifacts. The method described has been successfully used in comparative studies of the development of small intestines in mammals (pigs, mice, rats), reptiles, and birds (hens).
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Affiliation(s)
- Tomasz H Skrzypek
- Department of Biotechnology and Environmental Sciences, Laboratory of Confocal and Electron Microscopy, Center for Interdisciplinary Research, John Paul II Catholic University of Lublin, Lublin, Poland.,Department of Biotechnology and Environmental Sciences, Laboratory Ultrastructure and Electron Microscopy, John Paul II Catholic University of Lublin, Lublin, Poland
| | - Waldemar Kazimierczak
- Department of Biotechnology and Environmental Sciences, Laboratory of Biocontrol, Application and Production of EPN, Center for Interdisciplinary Research, John Paul II Catholic University of Lublin, Lublin, Poland
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Li WZ, Han WX, Hao XL, Zhao N, Zhai XF, Yang LB, He SM, Cheng YC, Zhang H, Fu LN, Zhang Y, Liang Z. An Optimized and Feasible Preparation Technique for the Industrial Production of Hydrogel Patches. AAPS PharmSciTech 2018; 19:1072-1083. [PMID: 29147871 DOI: 10.1208/s12249-017-0914-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 10/24/2017] [Indexed: 11/30/2022] Open
Abstract
For hydrogel patches, the laboratory tests could not fully reveal the existing problems of full scale of industrial production, and there are few studies about the preparation technique for the industrial manufacturing process of hydrogel patches. So, the purpose of this work was to elucidate the effects of mainly technological operation and its parameters on the performance of hydrogel patches at the industrial-scale production. The results revealed the following: (1) the aqueous phase was obtained by polyvinylpyrrolidone (PVP) along with tartaric acid dissolved in purified water, then feeding this into a vacuum mixer as a whole in one batch, thus extended the crosslinking reaction time of hydrogel paste (matrix) and allowed the operation of coating/cutting-off to be carried out easily, and there was no permeation of backing layer; (2) the gel strength of the hydrogel patches increased with the increase of working temperature, however, once the temperature exceeded 35 ± 2 °C, the hydrogel paste would lose water severely and the resultant physical crosslinking structure which has lower gel/cohesive strength would easily bring gelatinization/residues during application; (3) the relative humidity (RH) of the standing-workshop was dynamically controlled (namely at 35 ± 2 °C, keeping the RH at 55 ± 5% for 4 days, then 65 ± 5% for 2 days), which would make patches with satisfactory characteristics such as better flexibility, higher adhesive force, smooth flat matrix surface, and without gelatinization/residues and warped edge during the using process; (4) the aging of the packaged hydrogel patches was very sensitive to storage temperature, higher temperature, higher gel strength and lower adhesiveness. The storage temperature of 10 ± 2 °C could effectively prevent matrix aging and adhesion losing, which would also facilitate the expiration date of patches extended obviously. In conclusion, this work provides an optimized and feasible preparation technique for the industrial production of the hydrogel patches and establishes the hydrogel patches as a novel carrier for transdermal drug delivery.
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Phaechamud T, Mueannoom W, Tuntarawongsa S, Chitrattha S. Preparation of Coated Valproic Acid and Sodium Valproate Sustained-release Matrix Tablets. Indian J Pharm Sci 2011; 72:173-83. [PMID: 20838520 PMCID: PMC2929775 DOI: 10.4103/0250-474x.65026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 11/18/2009] [Accepted: 02/04/2010] [Indexed: 11/30/2022] Open
Abstract
The aim of this research was to investigate the technique for preparation of coated valproic acid and sodium valproate sustained-release matrix tablets. Different diluents were tested and selected as the effective absorbent for oily valproic acid. Effect of the amount of absorbent and hydroxypropylmethylcellulose on drug release from valproic acid-sodium valproate matrix tablets prepared with wet granulation technique was evaluated in pH change system. Colloidal silicon dioxide effectively adsorbed liquid valproic acid during wet granulation and granule preparation. The amounts of colloidal silicon dioxide and hydroxypropylmethylcellulose employed in tablet formulations affected drug release from the tablets. The drug release was prominently sustained for over 12 h using hydroxypropylmethylcellulose-based hydrophilic matrix system. The mechanism of drug release through the matrix polymer was a diffusion control. The drug release profile of the developed matrix tablet was similar to Depakine Chrono®, providing the values of similarity factor (f2) and difference factor (f1) of 85.56 and 2.37, respectively. Eudragit® L 30 D-55 was used as effective subcoating material for core matrix tablets before over coating with hydroxypropylmethylcellulose film with organic base solvent. Drug release profile of coated matrix tablet was almost similar to that of Depakine Chrono®.
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Affiliation(s)
- T Phaechamud
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon, Pathom-73000, Thailand
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