MyMedR

Displaying publications 1 - 20 of 114 in total

Abstract:

Sort:

Fulltext Comparative radiopacity of six current adhesive systems

de Moraes Porto IC, Honório NC, Amorim DA, de Melo Franco AV, Penteado LA, Parolia A

J Conserv Dent, 2014 Jan;17(1):65-9.
PMID: 24554865 DOI: 10.4103/0972-0707.124151

The radiopacity of contemporary adhesive systems has been mentioned as the indication for replacement of restorations due to misinterpretation of radiographic images.

Matched MeSH terms: Acrylic Resins
Effect of Thermal Cycling on Flexural Properties of Microcrystalline Cellulose-Reinforced Denture Base Acrylic Resins

Rahaman Ali AAA, John J, Mani SA, El-Seedi HR

J Prosthodont, 2020 Aug;29(7):611-616.
PMID: 30637856 DOI: 10.1111/jopr.13018

PURPOSE: To assess the impact of thermal cycling on flexural properties of denture base acrylic resin reinforced with microcrystalline cellulose (MCC) derived from oil palm empty fruit bunch (OPEFB).
MATERIALS AND METHODS: The flexural strength and flexural modulus, following thermal cycling (5000 cycles of 5-55°C) of 3 MCC-reinforced poly methyl methacrylate (PMMA) specimens were compared with the conventional and commercially available high-impact PMMA. The 3 test groups were represented by addition of various weight combinations of MCC and acrylic powders.
RESULTS: All 3 test groups with the addition of MCC demonstrated improved flexural strength and flexural modulus compared to the conventional resin, without and after thermal cycling. The highest mean flexural strength corresponded to the specimens reinforced with 5% MCC followed by 2% MCC.
CONCLUSION: Addition of MCC derived from OPEFB to PMMA may be a viable alternative to the existing, commercially available synthetic reinforced PMMA resins. The potential application of natural fillers in the fabrication of a reinforced denture base resin needs further study.

Matched MeSH terms: Acrylic Resins*
Fulltext Enhancement of Dose Response and Nuclear Magnetic Resonance Image of PAGAT Polymer Gel Dosimeter by Adding Silver Nanoparticles

Sabbaghizadeh R, Shamsudin R, Deyhimihaghighi N, Sedghi A

PLoS One, 2017;12(1):e0168737.
PMID: 28060829 DOI: 10.1371/journal.pone.0168737

In the present study, the normoxic polyacrylamide gelatin and tetrakis hydroxy methyl phosphoniun chloride (PAGAT) polymer gel dosimeters were synthesized with and without the presence of silver (Ag) nanoparticles. The amount of Ag nanoparticles varied from 1 to 3 ml with concentration 3.14 g/l, thus forming two types of PAGAT polymer gel dosimeters before irradiating them with 6 to 25 Gy produced by 1.25-MeV 60Co gamma rays. In this range, the predominant gamma ray interaction with matter is by Compton scattering effect, as the photoelectric absorption effect diminishes. MRI was employed when evaluating the polymerization of the dosimeters and the gray scale of the MRI film was determined via an optical densitometer. Subsequent analyses of optical densities revealed that the extent of polymerization increased with the increase in the absorbed dose, while the increase of penetration depth within the dosimeters has a reverse effect. Moreover, a significant increase in the optical density-dose response (11.82%) was noted for dosimeters containing 2 ml Ag nanoparticles.

Matched MeSH terms: Acrylic Resins*
Experimental assessment on feasibility of computed tomography-based thermometry for radiofrequency ablation on tissue equivalent polyacrylamide phantom

Tan D, Mohamad NA, Wong YH, Yeong CH, Cheah PL, Sulaiman N, et al.

Int J Hyperthermia, 2019;36(1):554-561.
PMID: 31132888 DOI: 10.1080/02656736.2019.1610800

Purpose: This study aimed to evaluate the effects of various computed tomography (CT) acquisition parameters and metal artifacts on CT number measurement for CT thermometry during CT-guided thermal ablation. Methods: The effects of tube voltage (100-140 kVp), tube current (20-250 mAs), pitch (0.6-1.5) and gantry rotation time (0.5, 1.0 s) as well as metal artifacts from a radiofrequency ablation (RFA) needle on CT number were evaluated using liver tissue equivalent polyacrylamide (PAA) phantom. The correlation between CT number and temperature from 37 to 80 °C was studied on PAA phantom using optimum CT acquisition parameters. Results: No statistical significant difference (p > 0.05) was found on CT numbers under the variation of different acquisition parameters for the same temperature setting. On the other hand, the RFA needle has induced metal artifacts on the CT images of up to 8 mm. The CT numbers decreased linearly when the phantom temperature increased from 37 to 80 °C. A linear regression analysis on the CT numbers and temperature suggested that the CT thermal sensitivity was -0.521 ± 0.061 HU/°C (R2 = 0.998). Conclusion: CT thermometry is feasible for temperature assessment during RFA with the current CT technology, which produced a high CT number reproducibility and stable measurement at different CT acquisition parameters. Despite being affected by metal artifacts, the CT-based thermometry could be further developed as a tissue temperature monitoring tool during CT-guided thermal ablation.

Matched MeSH terms: Acrylic Resins/chemistry*
Fulltext Surface profile analysis of laminated transfemoral prosthetic socket fabricated with different ratios of epoxy resin and acrylic resin

Zainuddin NAMN, Razak NAA, Karim MSA, Osman NAA

Sci Rep, 2023 Feb 15;13(1):2664.
PMID: 36792914 DOI: 10.1038/s41598-022-21990-y

Acrylic and epoxy are common types of resin used in fabricating sockets. Different types of resin will affect the internal surface of a laminated socket. This paper is to determine the best combination of ratio for epoxy and acrylic resin for a laminated prosthesis socket and to evaluate the surface profile analysis of different combinations of laminated prosthetic sockets for surface roughness. Transfemoral sockets were created using various resin-to-hardener ratios of 2:1, 3:1, 3:2, 2:3, and 1:3 for epoxy resin and 100:1, 100:2, 100:3, 100:4, and 100:5 for acrylic resin. Eight layers of stockinette consisting of four elastic stockinette and four Perlon stockinette were used. A sample with a size of 4 cm × 6 cm was cut out from the socket on the lateral side below the Greater Trochanter area. The Mitutoyo Sj-210 Surface Tester stylus was run through the sample and gave the Average Surface Roughness value (Ra), Root Mean Square Roughness value (Rq), and Ten-Point Mean Roughness value (Rz). Epoxy resin shows a smoother surface compared to acrylic resin with Ra values of is 0.766 µm, 0.9716 µm, 0.9847 µm and 1.5461 µm with 3:2, 3:1, 2:1 and 2:3 ratio respectively. However, for epoxy resin with ratio 1:3, the resin does not cure with the hardener. As for acrylic resin the Ra values are 1.0086 µm, 2.362 µm, 3.372 µm, 4.762 µm and 6.074 µm with 100: 1, 100:2, 100:5, 100:4 and 100:3 ratios, respectively. Epoxy resin is a better choice in fabricating a laminated socket considering the surface produced is smoother.

Matched MeSH terms: Acrylic Resins*
Deviation of the mandible corrected by an acrylic training flange

Hiong ET

Dent J Malaysia Singapore, 1972 May;12(1):53-5.
PMID: 4507359
Matched MeSH terms: Acrylic Resins
Fulltext Toxicity, pollution and biodegradation of acrylamide – a mini review

Kusnin, N., Syed, M.A., Ahmad, S.A.

Journal of Biochemistry, Microbiology and Biotechnology, 2015;3(2):6-12.
MyJurnal

Acrylamide is a monomer to polyacrylamide; a polymer with diverse application in basic research, industries and agriculture. The monomer is highly toxic while the polymeric form is slowly degraded to its monomeric form in the environment. In this mini review, the toxicity, uses, pollution and biodegradation of this important monomer are discussed. An important aspect of this review is to highlight the application of microorganisms as remediating agent for the removal of this compound from the environment.

Matched MeSH terms: Acrylic Resins
Fulltext Surface-Functionalized Superparamagnetic Nanoparticles (SPNs) for Enhanced Oil Recovery: Effects of Surface Modifiers and Their Architectures

Khalil M, Aulia G, Budianto E, Mohamed Jan B, Habib SH, Amir Z, et al.

ACS Omega, 2019 Dec 17;4(25):21477-21486.
PMID: 31867543 DOI: 10.1021/acsomega.9b03174

Superparamagnetic nanoparticles (SPNs) have been considered as one of the most studied nanomaterials for subsurface applications, including in enhanced oil recovery (EOR), due to their unique physicochemical properties. However, a comprehensive understanding of the effect of surface functionalization on the ability of the nanoparticles to improve secondary and tertiary oil recoveries remains unclear. Therefore, investigations on the application of bare and surface-functionalized SPNs in EOR using a sand pack were carried out in this study. Here, the as-prepared SPNs were functionalized using oleic acid (OA) and polyacrylamide (PAM) to obtain several types of nanostructure architectures such as OA-SPN, core-shell SPN@PAM, and SPN-PAM. Based on the result, it is found that both the viscosity and mobility of the nanofluids were significantly affected by not only the concentration of the nanoparticles but also the type and architecture of the surface modifier, which dictated particle hydrophilicity. According to the sand pack tests, the nanofluid containing SPN-PAM was able to recover as much as 19.28% of additional oil in a relatively low concentration (0.9% w/v). The high oil recovery enhancement was presumably due to the ability of suspended SPN-PAM to act as a mobility control and wettability alteration agent and facilitate the formation of a Pickering emulsion and disjoining pressure.

Matched MeSH terms: Acrylic Resins
Conformational destabilization of Bacillus licheniformis α-amylase induced by lysine modification and calcium depletion

Tan CY, Rahman RN, Kadir HA, Tayyab S

Acta Biochim. Pol., 2011;58(3):405-12.
PMID: 21887412

Bacillus licheniformis α-amylase (BLA) was chemically modified using 100-fold molar excess of succinic anhydride over protein or 0.66 M potassium cyanate to obtain 42 % succinylated and 81 % carbamylated BLAs. Size and charge homogeneity of modified preparations was established by Sephacryl S-200 HR gel chromatography and polyacrylamide gel electrophoresis. Conformational alteration in these preparations was evident by the larger Stokes radii (3.40 nm for carbamylated and 3.34 nm for succinylated BLAs) compared to 2.43 nm obtained for native BLA. Urea denaturation results using mean residue ellipticity (MRE) as a probe also showed conformational destabilization based on the early start of transition as well as ΔG(D)(H(2)O) values obtained for both modified derivatives and Ca-depleted BLA. Decrease in ΔG(D)(H(2)O) value from 5,930 cal/mol (for native BLA) to 3,957 cal/mol (for succinylated BLA), 3,336 cal/mol (for carbamylated BLA) and 3,430 cal/mol for Ca-depleted BLA suggested reduced conformational stability upon modification of amino groups of BLA or depletion of calcium. Since both succinylation and carbamylation reactions abolish the positive charge on amino groups (both α- and ε- amino), the decrease in conformational stability can be ascribed to the disruption of salt bridges present in the protein which might have released the intrinsic calcium from its binding site.

Matched MeSH terms: Acrylic Resins/chemistry
ATR-FTIR studies on ion interaction of lithium perchlorate in polyacrylate/poly(ethylene oxide) blends

Sim LH, Gan SN, Chan CH, Yahya R

Spectrochim Acta A Mol Biomol Spectrosc, 2010 Aug;76(3-4):287-92.
PMID: 20444642 DOI: 10.1016/j.saa.2009.09.031

The interaction behaviours between components of polyacrylate (PAc)/poly(ethylene oxide) (PEO) and lithium perchlorate (LiClO(4)) were investigated in detail by Attenuated Total Reflectance (ATR)-Fourier Transformed Infrared (FTIR) spectroscopy. Solution cast films of the PAc/PEO and PAc/PEO/LiClO(4) were examined. No obvious shifting of the characteristic ether and ester group stretching modes of PEO and PAc was observed, indicating incompatibility of the binary PAc/PEO blend. The spectroscopic studies on the PAc/PEO/LiClO(4) blends reveal that Li(+) ions coordinate individually to the polymer components at the ether oxygen of PEO and the C-O of the ester group of PAc. Frequency changes observed on the nu(C-O-C) and omega(CH(2)) of PEO confirm the coordination between PEO and Li(+) ions resulting in crystallinity suppression of PEO. The absence of experimental evidence on the formation of PEO-Li(+)-PAc complexes suggests that LiClO(4) does not enhance the compatibility of PAc/PEO blend.

Matched MeSH terms: Acrylic Resins/chemistry*
Treatment of pulp and paper mill wastewater by polyacrylamide (PAM) in polymer induced flocculation

Wong SS, Teng TT, Ahmad AL, Zuhairi A, Najafpour G

J Hazard Mater, 2006 Jul 31;135(1-3):378-88.
PMID: 16431022

The flocculation performances of nine cationic and anionic polyacrylamides with different molecular weights and different charge densities in the treatment of pulp and paper mill wastewater have been studied. The experiments were carried out in jar tests with the polyacrylamide dosages range of 0.5-15 mg l(-1), rapid mixing at 200 rpm for 2 min, followed by slow mixing at 40 rpm for 15 min and settling time of 30 min. The effectiveness of the polyacrylamides was measured based on the reduction of turbidity, the removal of total suspended solids (TSS) and the reduction of chemical oxygen demand (COD). Cationic polyacrlyamide Organopol 5415 with very high molecular weight and low charge density is found to give the highest flocculation efficiency in the treatment of the paper mill wastewater. It can achieve 95% of turbidity reduction, 98% of TSS removal, 93% of COD reduction and sludge volume index (SVI) of 14 ml g(-1) at the optimum dosage of 5 mg l(-1). SVI values of less than 70 m lg(-1) are found for all polyacrylamide at their respective optimum dosage. Based on the cost evaluation, the use of the polyacrylamides is economically feasible to treat the pulp and paper mill wastewaters. This result suggests that single-polymer system can be used alone in the coagulation-flocculation process due to the efficiency of the polyacrylamide. Sedimentation of the sludge by gravity thickening with settling time of 30 min is possible based on the settling characteristics of the sludge produced by Organopol 5415 that can achieve 91% water recovery and 99% TSS removal after 30 min settling.

Matched MeSH terms: Acrylic Resins/chemistry*
Comparison of linear-linear and hyperbranched-linear dental composite

Darmawati MY, Ismarul N, Fuad Y, Fazan F

Med J Malaysia, 2004 May;59 Suppl B:27-8.
PMID: 15468802

Linear polymers have been commonly used as dental composite. However the aim of this work is to use hyperbranched polymer in an attempt to produce dental composite. The reason is because the dendritic molecules have shown low viscosity at higher molecular weight compared to the linear counterparts. Therefore, this work attempts to substitute the linear polymer with as much of hyperbranched polymer in the dental composite that would pass the required ISO 4049:1998(E) "Dentistry - Resin-based filling material". Several formulations of dental composites were used, i.e. combinations of linear-linear and linear-hyperbranched polymers for comparison. Following this, physical and mechanical characterisation were conducted based on the ISO standards such as water sorption and water solubility. Other characterisation such as polymerisation shrinkage and Vickers hardness were also evaluated. It was found that different types of resins give different physical and mechanical properties. The maximum achievable hyperbranched polymer, which passes the required ISO standard, that can be incorporated in the linear polymer to form dental composite is 43% wt.

Matched MeSH terms: Acrylic Resins/standards*
Acrylic-based genosensor utilizing metal salphen labeling approach for reflectometric dengue virus detection

Mazlan NF, Tan LL, Karim NHA, Heng LY, Jamaluddin ND, Yusof NYM, et al.

Talanta, 2019 Jun 01;198:358-370.
PMID: 30876573 DOI: 10.1016/j.talanta.2019.02.036

An optical genosensor based on Schiff base complex (Zn2+ salphen) DNA label and acrylic microspheres (AMs) as polymer support of the capturing DNA probe (cpDNA) was developed for dengue virus serotype 2 (DEN-2) detection via reflectance spectrophotometric method. The solid-state optical DNA biosensor showed high selectivity and specificity up to one-base mismatch in the target DNA sequence owing to the salphen chemical structure that is rich in localized electrons, and allowed π-π stacking interaction between stacked base pairs of double-stranded DNA (dsDNA). The reflectometric DNA microsensor demonstrated a broad linear detection range towards DEN-2 DNA from 1 × 10-15 M to 1 × 10-3 M with a low limit of detection (LOD) obtained at 1.21 × 10-16 M. The DNA biosensor gave reproducible optical response with a satisfactory relative standard deviation (RSD) at 3.1%, (n = 3), and the reflectance response was stable even after four regeneration cycles of the DNA biosensor. The optical genosensor was proven comparable with standard reverse transcription polymerase chain reaction (RT-PCR) in detecting DEN-2 genome acquired from clinical samples of serum, urine and saliva of dengue virus infected patients under informed consent. The developed reflectometric DNA biosensor is advantageous in offering an early DEN-2 diagnosis, when fever symptom started to manifest in patient.

Matched MeSH terms: Acrylic Resins/chemistry*
Fulltext Dataset on structure and mechanical properties of electrospun polyacrylonitrile nanofibrous mesh reinforced by halloysite nanotubes

Goh KL, Makaremi M, Pasbakhsh P, De Silva R, Zivkovic V

Data Brief, 2018 Dec;21:2170-2178.
PMID: 30555856 DOI: 10.1016/j.dib.2018.11.039

The mechanical properties of electrospun polyacrylonitrile (PAN)-based membranes for ultrafiltration, such as oil-water separation and heavy metals from water, are often characterised in the dry state but little is known about the membrane properties in the hydrated state. This dataset comprised mechanical properties and structure-related properties of electrospun PAN-based membranes. The mechanical dataset described the yield strength and strain, stiffness, resilience energy, fracture strength, strain at fracture and fracture toughness of electrospun neat PAN and halloysite nanotube (HNT) reinforced PAN membranes in both hydrated and dry states. The data related to the hydrated state were derived from direct measurements of the mechanical properties of the PAN-based membrane using a novel environmental micromechanical tester. The structure-related dataset comprised electron micrographs and quantitative measurements (fibre diameter and pore diameter) derived from the micrographs. For further interpretation and discussion of the dataset, the reader is referred to the research data article, "Direct measurement of the elasticity and fracture properties of electrospun polyacrylonitrile/halloysite fibrous mesh in water" (Govindasamy et al., 2014).

Matched MeSH terms: Acrylic Resins
Effect of mixed tropical hardwood kraft pulp and polyacrylamide types on magnetite retention in lumen loaded handsheets

Ainun Zuriyati Mohamed, Sarani Zakaria, Roslinda Shamsuddin, Mustaffa Abdullah

Sains Malaysiana, 2010;39.

This paper reports on the preparation of magnetic lumen loaded handsheets from bleached and unbleached mixed tropical hardwood kraft pulps. The lumen coating technique is a physical approach whereby fillers were deposited inside the fibre lumen. In order to produce magnetically responsive fibres, magnetic fillers were loaded into the fibre lumen. The magnetic filler chosen was magnetite which is usually used to make mylar as found in a diskette. Low and high molecular weights of polyacrylamide (PAM) were used as retention aids. The effect of different molecular weight of PAM on filler content in the bleached and unbleached handsheets were studied. The results showed that the amount of fillers deposited in the pulp fibres increased with increasing molecular weight of PAM using both pulps. However the bleached pulps gave better lumen loading than the unbleached when using high molecular weight of PAM.

Matched MeSH terms: Acrylic Resins
Sifat fizikal dan kajian in vitro tablet matriks pelepasan tertahan ketoprofen

Ibrahim Ijang, Mohd Cairul Iqbal Mohd Amin, Bukhori Abu Bakar

Sains Malaysiana, 2010;39.

Penggunaan formulasi tablet pelepasan tertahan untuk dadah anti-inflamatori bukan steroid (DAIBS) seperti aspirin berupaya melindungi lapisan perut dari kesan buruk jus asid tubuh. Kajian ini dilakukan untuk menilai keberkesanan formulasi tablet matriks pelepasan tertahan dengan kepelbagaian kepekatan polimer bersama ketoprofen sebagai model. Tablet dibangunkan dengan menggunakan kaedah granulasi basah yang terdiri daripada polimer hidrofilik (hidroksipropil metilselulosa), polimer hidrifobik bersandar pada pH (Eudragit L100-55) dan polimer tak bersandar pada pH (Eudragit R100) sebagai bahan asas pembentukan matriks pada kepekatan 10, 20 dan 30%b/b. Semua formulasi dimampatkan dengan menggunakan mesin pentabletan yang mempunyai penebuk berbentuk cembung bersaiz 10 mm. Tablet yang terhasil diuji daripada segi keseragaman berat, kekerasan, kerapuhan, ketebalan, peratus kandungan dadah dan kajian pelepasan in vitro menggunakan kaedah BP 2007. Hasil menunjukkan kadar pelepasan dadah dikawal oleh jenis dan kepekatan polimer di dalam formulasi matriks. Secara umumnya peningkatan kepekatan kandungan polimer di dalam tablet matriks didapati mengurangkan kadar pelepasan dadah. Perbandingan polimer melalui kepekatan yang sama menggunakan t50%, pula mendapati terdapat perbezaan statistik bermakna (p<0.05) pada kadar pelepasan dadah. Berdasarkan kepada pelepasan dadah dalam kajian in vitro, polimer hidrofobik bersandar pada pH (Eudragit L100-55) menunjukkan profil pelepasan dadah secara tertib sifar yang terbaik berbanding polimer yang lain.

Matched MeSH terms: Acrylic Resins
Fulltext Adhesion of Candida Albicans to digital versus conventional acrylic resins: a systematic review and meta-analysis

Alhajj MN, Halboub E, Yacob N, Al-Maweri SA, Ahmad SF, Celebić A, et al.

BMC Oral Health, 2024 Mar 04;24(1):303.
PMID: 38439020 DOI: 10.1186/s12903-024-04083-2

BACKGROUND: The present systematic review and meta-analysis investigated the available evidence about the adherence of Candida Albicans to the digitally-fabricated acrylic resins (both milled and 3D-printed) compared to the conventional heat-polymerized acrylic resins.
METHODS: This study followed the guidelines of the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). A comprehensive search of online databases/search tools (Web of Science, Scopus, PubMed, Ovid, and Google Scholar) was conducted for all relevant studies published up until May 29, 2023. Only in-vitro studies comparing the adherence of Candida albicans to the digital and conventional acrylic resins were included. The quantitative analyses were performed using RevMan v5.3 software.
RESULTS: Fourteen studies were included, 11 of which were meta-analyzed based on Colony Forming Unit (CFU) and Optical Density (OD) outcome measures. The pooled data revealed significantly lower candida colonization on the milled digitally-fabricated compared to the heat-polymerized conventionally-fabricated acrylic resin materials (MD = - 0.36; 95%CI = - 0.69, - 0.03; P = 0.03 and MD = - 0.04; 95%CI = - 0.06, - 0.01; P = 0.0008; as measured by CFU and OD respectively). However, no differences were found in the adhesion of Candida albicans between the 3D-printed digitally-fabricated compared to the heat-polymerized conventionally-fabricated acrylic resin materials (CFU: P = 0.11, and OD: P = 0.20).
CONCLUSION: The available evidence suggests that candida is less likely to adhere to the milled digitally-fabricated acrylic resins compared to the conventional ones.

Matched MeSH terms: Acrylic Resins
Rheological behavior of biodegradable N-succinyl chitosan-g-poly (acrylic acid) hydrogels and their applications as drug carrier and in vitro theophylline release

Bashir S, Teo YY, Ramesh S, Ramesh K, Mushtaq MW

Int J Biol Macromol, 2018 Oct 01;117:454-466.
PMID: 29807081 DOI: 10.1016/j.ijbiomac.2018.05.182

Novel pH sensitive N-succinyl chitosan-g-poly (acrylic acid) hydrogels were synthesized through free radical mechanism. Rheometer was used to observe the mechanical strength of the hydrogels. In vitro degradation was conducted in SIF (pH 7.4). The effect of concentration of monomers, initiator, and crosslinking agent and pH and ionic strength of NaCl, CaCl2, and AlCl3 on swelling of the hydrogels was observed. The results showed that equilibrium swelling ratio was highly influenced by concentration of monomers, initiator, and crosslinking agent concentration, and pH and salt solutions of NaCl, CaCl2, and AlCl3. The swelling kinetics revealed that swelling followed non-Fickian anomalous transport. Furthermore, theophylline loading (DL %) and encapsulation efficiency (EE %) of the hydrogels was in the range of 15.5 ± 0.15-22.8 ± 0.06% and 62 ± 0.15-91 ± 0.26%, respectively. The release of theophylline in physiological mediums was strongly influenced by the pH. The theophylline release was in the range of 51 ± 0.20-92 ± 0.12% in SIF and 7.4 ± 0.02-14.9 ± 0.03% in SGF (pH 1.2), respectively. The release data fitted well to Korsmeyer-Peppas model. The chemical activity of the theophylline suggested that drug maintained its chemical activity after release in vitro. The results suggest that synthesized hydrogels are excellent drug carriers.

Matched MeSH terms: Acrylic Resins/chemical synthesis; Acrylic Resins/chemistry*
Fulltext Physical properties and cytotoxicity comparison of experimental gypsum-based biomaterials with two current dental cement materials on L929 fibroblast cells

Mahshim N, Reza F, Omar NS

J Conserv Dent, 2013 Jul;16(4):331-5.
PMID: 23956536 DOI: 10.4103/0972-0707.114364

To evaluate physical properties and cytotoxicity of pure gypsum-based (pure-GYP) and experimental gypsum-based biomaterials mixed with polyacrylic acid (Gyp-PA). The results were compared with calcium hydroxide (CH) and glass ionomer cement (GIC) for application as base/liner materials.

Matched MeSH terms: Acrylic Resins
Development of an Hg(II) fibre-optic sensor for aqueous environmental monitoring

Ahmad M, Hamzah H, Sufliza Marsom E

Talanta, 1998 Oct;47(2):275-83.
PMID: 18967326

An optical sensor for Hg(II) monitoring using a complex of zinc dithizonate immobilised on XAD 7 which is based on reflectance spectrophotometry has been developed in this study. Measurements were made using a kinetic approach whereby the reflectance signal is measured at a fixed time of 5 min. The sensor could be regenerated using a saturated solution of KCl in 1 M sulphuric acid. The sensor was found to have an optimum response at pH 3.0 with respective measurement repeatability and probe-to-probe reproducibility of 1.53% and 5.26%. A linear response was observed in the Hg(II) concentration range of 0.0-180.0 ppm with a calculated limit of detection (LOD) of 0.05 ppm. The results obtained for aqueous Hg(II) determination using this probe were found to be comparable with the well-established method of atomic absorption spectrometry.

Matched MeSH terms: Acrylic Resins

Filters

Please provide feedback to Administrator ([email protected])

External Links