Direct Incorporation Method Research Articles

Production and characterization of polyvinyl alcohol films containing essential oil

Packaging plays an important role in protecting foodstuffs against physicochemical damage and microbial activity, as well as extending shelf life. In recent years, petrochemical compounds that cause environmental pollution and contamination due to their non-biodegradability have been replaced by biocompatible polymer-based films in the food packaging industry. Due to aromatic essential oils (EO), various biological activities, and their potential to replace chemical preservatives in the field of food preservation, Star Anise essential oil, which has properties, such as free radical scavenger, antibacterial, antifungal and antiviral, was used as an additive in this study. Biodegradable and biocompatible polyvinyl alcohol (PVA) polymer was used as the matrix and polymer-based films were produced in 3 different concentrations. Spectral analysis, structural, chemical, and thermal characterizations, and surface morphologies of the produced films by the direct incorporation method were examined. In addition, the antibacterial activities of the films on Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 25922, and Acinetobacter baumannii ATCC BAA 747 bacteria were investigated. As a result of the examinations, it was determined that an interfacial interaction occurred between the matrix and the filler, and the produced films were thermally resistant and showed antibacterial activity against Gram (+)/Gram (−) bacteria. Consequently, it can be concluded that PVA films containing Star Anise essential oil present a prospective substitute in a variety of industrial packaging systems, including those for food, medicine, and cosmetics.

A novel carbon reducing natural composite phase change material for effective energy storage

The development of fatty acid made from natural composite materials Lac, Rosin, Flowers of silk cotton, Red ochre, Cinnabar, Beeswax, and Butter as a novel bio-based Natural Composite Phase Change Material (NCPCM) is the subject of the present study. This bio-based material was produced for the first time using natural, readily available, inexpensive, and eco-friendly with a peak phase transition temperature of 75 °C and 194 J/g as the latent heat capacity of fusion. Three distinct compositions, 2 %, 3 % and 5 % of NCPCM to the weight of the binder, were produced by the direct incorporation method into the natural hydraulic lime matrix. The newly developed NCPCM-incorporated lime mortar specimens were characterized based on their physical, mechanical, and thermal properties, and their results were compared with reference lime mortar (RLM). The compressive strength of NCPCM2 and NCPCM3 at 28 days increased by 22.64 % and 47.42 %, respectively. The produced NCPCM retains good thermal stability in its temperature operating range. The XRD findings showed that adding Lac and Rosin containing carboxylic acid esters of fatty acids increased the calcium carbonate formation. The produced FTIR validated the produced material's chemical stability, and SEM images demonstrated that the developed matrix's morphology successfully retains the added bio-additives. From an environmental perspective, the prepared NCPCM in lime mortar can reduce CO2 emissions by 296 kg·CO2/kg and 286 kg·CO2/kg. Furthermore, adding the produced NCPCM as bio-additives to lime mortar can explore the creation of sustainable mortar, which leads to environmental and economic benefits.

PMMA/SWCNT Composites with Very Low Electrical Percolation Threshold by Direct Incorporation and Masterbatch Dilution and Characterization of Electrical and Thermoelectrical Properties.

In the present study, Poly(methyl methacrylate) (PMMA)/single-walled carbon nanotubes (SWCNT) composites were prepared by melt mixing to achieve suitable SWCNT dispersion and distribution and low electrical resistivity, whereby the SWCNT direct incorporation method was compared with masterbatch dilution. An electrical percolation threshold of 0.05-0.075 wt% was found, the lowest threshold value for melt-mixed PMMA/SWCNT composites reported so far. The influence of rotation speed and method of SWCNT incorporation into the PMMA matrix on the electrical properties and the SWCNT macro dispersion was investigated. It was found that increasing rotation speed improved macro dispersion and electrical conductivity. The results showed that electrically conductive composites with a low percolation threshold could be prepared by direct incorporation using high rotation speed. The masterbatch approach leads to higher resistivity values compared to the direct incorporation of SWCNTs. In addition, the thermal behavior and thermoelectric properties of PMMA/SWCNT composites were studied. The Seebeck coefficients vary from 35.8 µV/K to 53.4 µV/K for composites up to 5 wt% SWCNT.

Synthesis of Mesoporous Silica Imprinted Salbutamol with Two TEOS/MTES Ratio Compositions through the Direct Incorporation Method for Salbutamol Separation.

Molecularly imprinted mesoporous silica (MIPMS) is one of the methods to improve site accessibility molecule target on molecularly imprinted polymer (MIP) for application in solid-phase extraction (SPE). The MIPMS was prepared using salbutamol sulfate as template molecule, cetyltrimethylammonium bromide as a directing agent, and tetraethyl orthosilicate and methyltriethoxysilane were used as silica precursor and organosilane. In this study, two TEOS : MTES ratios were used. The MIPMS-2 with 3 : 1 ratio of TEOS : MTES has better analytical performance than the MIPMS-1 with 2 : 1 ratio of TEOS : MTES. The adsorption capacity of MIPMS-2 was about 0.0934 mg/g, and it was 0.0407 mg/g for NIPMS-2. The extraction ability of MIPMS-2 was good, with a recovery of about 104.79% ± 1.01% of salbutamol in spiked serum. The imprinting factor (IF) value obtained is 1.2. When serum was spiked with salbutamol and terbutaline, the ability of NIPMS-2 to recognize salbutamol increased. Therefore, optimizing the conditions for the MIPMS synthesis is necessary to produce a sorbent with better selectivity.

Hydrogen-induced modification of the interface between matrix and ceramic phase of (TiB + TiC)/Ti–6Al–4V

This work intends to investigate the effect of melt hydrogenation on the interface between reinforcements and matrix. A novel method for direct incorporation of trace hydrogen atoms into composites by melting alloys under a mixed gas of hydrogen and argon (termed “melt hydrogenation”) is used to fabricate (TiB+TiC)/Ti–6Al–4V. Experimental observations illustrate that the hydrogen optimizes interface bonding strength, which is manifested in that the load can be more efficiently transferred from the matrix to the reinforcement. It is found that the thickness of the “transition layer” at the interface becomes thinner as the hydrogen content increases, characterized by the line scan mode of the transmission electron microscope. When the hydrogen content reaches 7.87 × 10−2 wt%, the atomic arrangement at the interface gets so orderly that the interface is strictly coherent according to the orientation relationship. These findings are of great significance for revealing the optimization mechanism of hydrogen on composite interfaces.

Effective thermal conductivity measurement of PCM composites during phase transition by using the transient plane source method

The thermal conductivity of phase change materials (PCMs) during phase transitions is of great significance to the evaluation of the thermal performance of energy-saving buildings. Based on the transient plane source method, a method for measuring the effective thermal conductivity of PCM composites was proposed, by which the variations in effective thermal conductivity with liquid fraction and temperature during phase transitions can be obtained. The correctness of the proposed method was verified through matched simulation experiments. Three kinds of PCM samples were prepared for experimental measurement on the basis of the direct incorporation method, and the volume proportions of decanoic acid to gypsum were set to 10%, 12%, and 15%. The phase transition regions and latent heat values of these PCM samples were measured using the differential scanning calorimetry technique. Results showed that the effective thermal conductivity of the PCM first increased and then decreased during the phase transition. As the fraction of PCM content increased, the phase transition regions gradually expanded, and the effective thermal conductivity changed more drastically. The good measurement repeatability demonstrated the feasibility of this method for measuring the effective thermal conductivity of composites during phase transition.

Fabrication of form stable composite phase change materials for thermal energy storage by direct powder incorporation with a preheating process

This work concerns with form stable composite phase change materials (FSCPCMs) for thermal energy storage applications. A vast knowledge base has been established in formulation design, material selection and characterisation. However, research efforts on manufacturing technologies are insufficient, leading to limited information on the relationship between manufacture processes and product properties - the main motivation for this work. A commonly used fabrication method is the so-called direct powder incorporation method. We have modified the direct incorporation method by the integration of a preheating process and used the modified method to fabricate a KNO3-diatomite based FSCPCM. The characterisation of the fabricated FSCPCMs showed that the preheating method not only densified the microstructure, but also gave a significant increase in the thermal conductivity (by 54.91%). The improvements were found to be associated with wettability of the PCM on the matrix surface, whereas porous structure of the matrix material has a small effect.

Peningkatan konduktivitas termal lemak sapi sebagai bahan PCM dengan menambahkan arang sekam padi

Phase change material (PCM) is a material that can absorb and store energy and can release it based on the principle of latent heat energy storage. Beef tallow is one of the materials that can be used as PCM but its low thermal conductivity is around 0.181 W/mK. Hence, thermal conductivity is considered an important factor in the conduction heat transfer. This further affects kinetic absorption and heat release. However it is possible to increase the values by adding another material that has a high thermal conductivity. The purpose of this study is to elevate the thermal conductivity of beef tallow by adding rice husk char. This research involves direct incorporation method, where beef tallow is thawed and mixed with the rice husk char then stirred with a rotation of 100 rpm until the mixture becomes solid. Addition of rice husk char with weight fractions of 5 and 10% and grain size of 0.045 mm. Subsequently, thermal conductivity test was performed using the TQ Heat Transfer Experiment Base Unit.The results show that with the addition of rice husk can increase the thermal conductivity of PCM beef tallow. The increase obtained in the addition of 10% rice husk char is 37 times compared to the pure sample. Based on this result it is concluded that carbon-based materials such as rice husk char can be used to increase the thermal conductivity of PCM materials.

Energy Deficit Attenuates Muscle Protein Synthetic Responses To Essential Amino Acids

BACKGROUND: Peripheral essential amino acid (EAA) concentrations regulate muscle protein synthesis (MPS). During energy balance, consuming ~9 g EAA doubles postprandial peripheral EAA concentrations and increases resting MPS by nearly 50%. During energy deficit, EAA requirements may be elevated due to a greater carbon skeleton requirement for energy metabolism. We examined if similar or greater increases in peripheral EAA concentrations during energy deficit stimulate the same magnitude increase in MPS as in energy balance. PURPOSE: Determine the effects of peripheral increases in EAA concentrations and the stimulation of MPS during energy balance and deficit. METHODS: Data were derived from two independent controlled studies assessing the effects of consuming high and low doses of EAA on peripheral EAA concentrations and MPS (2H5-phenylanine, direct incorporation method) during energy balance (BAL HIGH/LOW) and energy deficit (DEF HIGH/LOW). In BAL, measures were determined in 8 healthy adults (mean ± SD; 21.4 ± 2 y, 24.6 ± 3.2 kg/m2 ), ingesting in random order, either 4.3 ± 0.0 g or 8.6 ± 0.0 g EAA, separated by 7 d. In DEF, measures followed 5 days of controlled energy deficit (30 ± 4 %) in 19 healthy adults (22.9 ± 5 y, 25.4 ± 2.7 kg/m2), ingesting either 7.8 ± 0.9 g or 23.5 ± 2.6 g EAA, in random order, separated by 14 d. RESULTS: Peak EAA concentrations were 36% higher in DEF HIGH compared to BAL HIGH (2219 ± 470 vs. 1634 ± 320 μmol/L; p<0.05), but not for the low doses. Peak EAA concentrations were higher (p<0.05) in HIGH doses for both energy states compared to LOW doses. Independent of EAA dose, postprandial MPS for BAL (0.78 ± 0.36 %/h) and DEF (0.58 ± 0.15 %/h) were 81% and 26% greater than postabsorptive MPS for BAL (0.43 ± 0.18 %/h) and DEF (0.46 ± 0.24 %/h), respectively (energy-by-fed state, p<0.05). Postprandial MPS was 25% lower in DEF than BAL (energy-by-state, p<0.05). CONCLUSION: Ingesting roughly triple the dose of EAA in DEF than BAL (23.5 g vs. 8.6 g) resulted in marked differences in peripheral concentrations; yet the anabolic stimulus was similar. The reduction in postprandial MPS during DEF, despite ingesting 2-3 times the amount of EAA compared to BAL, suggests that muscle is not the primary target for the greater rise in peripheral EAA. Supported by USAMRDC; authors’ views not official U.S. Army or DoD policy.

Anti-corrosive performance of epoxy coatings containing various nano-particles for splash zone applications

Various formulations of epoxy nano-composites coating were developed by incorporating the nanoparticles (NPs) of ZnO, ZrO2, and SiO2 (2 wt%) in commercially available epoxy resin as the matrix phase. Direct incorporation method was used for the addition of NPs in epoxy matrix. High-speed mechanical stirring and ultra-sonication were carried out to facilitate the dispersion of NPs in the presence of acetone used as a solvent. Coating of neat epoxy and NPs (ZnO, ZrO2, SiO2) doped coating was applied on mild steel substrate for corrosion analysis. The effect of the incorporation of various NPs on anti-corrosive properties of the epoxy/nano-composite coatings was investigated by electrochemical impedance spectroscopy technique. The experimental results showed an improvement in the anticorrosive properties for EZr coatings as compared with pristine and other nanocomposite coating samples.

On the nature of Cr species on MCM-41 obtained by a one step method and their enhanced photocatalytic performance under visible radiation: New insights by a combined techniques approach

MCM-41 materials modified with several Cr/Si molar ratios by a direct incorporation method and then with Ti by impregnation, were characterized by different instrumental techniques. In order to develop new photocatalysts that uses more efficiently solar light, the aim of this work was to evaluate the direct incorporation method to synthesize Cr-modified MCM-41. The synthesized solids were tested as photocatalysts for the Acid Orange 7 (AO7) degradation in aqueous solution. The catalysts with Si/Cr molar ratios of 60 and 40 led to AO7 degradations higher than 70% after the Ti loading. Thus, it could be confirmed that the direct incorporation method of Cr in the synthesis gel favored the high dispersion of the active species of Cr6+ making them accessible to interact with Ti species. Finally, the presence of Ti is crucial to achieve a better use of the radiation due to the synergistic effect with the Cr species besides avoiding the loss of this metal to the reaction medium.

Direct incorporation method for the synthesis of molybdophosphate/MCM-41 silica composite: Adsorption study of heavy metals from aqueous solutions

The direct incorporation of α-Keggin structure, [PMo12O40]3−, derived from ammonium molybdophosphate into the mesopores of MCM-41 silica to synthesis MP/MCM-41 composite was carried out using soft-templating approach which based on surfactant self-assembly. The aimed composite material was characterized by XRD, FT-IR, SEM and BET techniques. Sorption properties of the synthesized composite powder were evaluated through sorption of lead, copper and cadmium ions from their multicomponent aqueous solutions. Preliminary studies of cation hydrolysis using MINTEQA2 software program was accomplished indicating that at pH of 5 the highest percent of free Pb2+, Cu2+ and Cd2+ was attained. Batch sorption tests were carried out at different initial heavy metal ion concentrations revealing that the synthesized composite has great selectivity to lead ions over copper and cadmium ions. The experimentally obtained sorption results were analyzed using pseudo-1st and -2nd order kinetic models to stand on the possible sorption mechanisms indicating the sorption behavior of the studied ions onto MP/MCM-41 composite belonged to the pseudo 2nd order kinetic model and the sorption process was a chemical process. Isotherm plots were constructed and analyzed using Langmuir and Freundlich isotherm models. Results indicated that the best fitting to the experimentally obtained data was obtained when Langmuir isotherm model was applied.

Performance of nanosilica in acrylic polyol 2K polyurethane coatings

PurposeThe purpose of this paper is to formulate two component polyurethane coatings based on acrylic polyol, to study the effects of variable nanosilica loadings in these coatings on different morphological, optical, mechanical, corrosion resistance and weather resistance properties and to study the intercalation of acrylic polyol molecules into nanosilica crystals by XRD technique.Design/methodology/approachTwo component polyurethane coatings were synthesised using acrylic polyol and isocyanate HDI. The nanosilica was incorporated in polyurethane formulation at the weight ratios of 1%, 3% and 5% based on total weight of polyol and isocyanate. The performance of nanocoatings was compared for variable loads of nanosilica for different properties such as morphological, optical, mechanical, corrosion resistance, weather resistance and were studied for intercalation of acrylic polyol into nanosilica crystals by XRD technique.FindingsImprovement in the properties of polyurethane coatings is achieved with the incorporation of nanosilica. The improvement is the result of inherently high properties of inorganic nanosilica. Tensile strength, scratch hardness, abrasion resistance, corrosion and weathering resistance show significant improvement in performance with the incorporation of nanosilica. Properties are found to deteriorate beyond a certain loading of nanosilica; hence it is important to optimise loading level. The optimal range for high performance was found to be in the range of 1% to 3%. The improvement was a result of synergistic behaviour and good interfacial interaction between polyurethane and nanosilica at optimal levels.Research limitations/implicationsThe method used for incorporation of nanosilica into polyurethane was direct incorporation method. The other method of incorporation, i.e. in situ addition and its effect on properties can also be studied.Practical implicationsWith the addition of optimal loading level of nanosilica to polyurethane coatings, properties can be enhanced up to the mark. The addition is relatively easy and cost effective.Originality/valueThe paper proves the significance of incorporation of nanosilica on original properties of polyurethane coatings and widens the area of applications of two component polyurethane coatings from acrylic polyol by strengthening them in their properties. The coatings can be applicable in high performance topcoats especially for automotive topcoats.

Evolution of Copper Nanospecies in the Synthesis Stages of MCM-41-Type Mesoporous Molecular Sieves

The redox behavior of copper nanospecies in the synthesis stages of MCM-41-type materials has been followed by ESR technique. These copper-modified mesoporous molecular sieves (Cu-MMS) were synthesized by direct incorporation method, and different treatments of the initial synthesis gel were evaluated. From ESR and UV–vis-DRS data, a synergistic approach about the distribution of copper species in the different catalysts has been made: the hydrothermal treatment favors the incorporation of isolated cooper species into the framework, whereas both the aging treatment and the lack of subsequent treatment promote the formation of copper clusters into the mesoporous channels. The Hamiltonian parameters g// ≈ 2.3 and g⊥ ≈ 2.06 have confirmed the presence of isolated Cu2+ ions in octahedral coordination with tetragonal distortion within siliceous framework, whereas the g ≈ 2.2 value was assigned to the presence of Cu2+ clusters. Only the catalyst aged at room temperature has presented additional signals characte...

Exercise and NSAIDs

The purpose of this study was to determine muscle and tendon protein fractional synthesis rates (FSR) at rest and after a one-legged kicking exercise in patients with knee osteoarthritis (OA) receiving either placebo or nonsteroidal anti-inflammatory drugs (NSAIDs). Twenty patients with knee OA (50-70 yr) were enrolled. For each of the 3 days before the exercise intervention, 9 patients were administered NSAIDs (1200 mg), and 11 patients were administered placebo in a double-blinded manner. Each patient performed 60 min of one-legged kicking at 55% of workload maximum while the contralateral leg remained rested. Twenty-four hours after exercise, we determined circulating concentrations of inflammatory parameters and measured FSR of myofibrillar and sarcoplasmic protein fractions of vastus lateralis muscle and patellar tendon collagen protein by the direct incorporation method using a flooding dose of 13C/12C-proline. Circulating levels of prostaglandin F2α were lower in the NSAID group compared with the placebo group (P < 0.05). There was an overall significant effect of exercise on FSR in muscle myofibrillar (P = 0.003) and sarcoplasmic protein (P = 0.026) but not in tendon collagen protein (P = 0.52). No overall significant effect of the drug was seen on either of the tissue protein fractions (P > 0.05) or on the interaction between the drug and exercise on FSR in tendon collagen (P = 0.21), muscle myofibrillar (P = 0.68), or sarcoplasmic protein, FSR (P = 0.16). In elderly patients with knee OA, an acute bout of moderate exercise significantly increases FSR of muscle myofibrillar and sarcoplasmic protein, but not tendon collagen, 24 h after exercise. NSAID administration in patients with knee OA reduced the level of circulating prostaglandin F2α but did not diminish the exercise-induced response of muscle contractile protein FSR. However, we cannot exclude that a minor inhibition of muscle sarcoplasmic proteins may have been present with NSAID treatment. This study suggests that muscle hypertrophy after long-term training is not influenced by NSAIDs.

Utilization of a By-Product Produced from Oxidative Desulfurization Process Over Cs-Mesoporous Silica Catalysts

We investigated the use of Cs-mesoporous silica catalysts to upgrade a by-product of oxidative desulfurization (ODS). Cs-mesoporous silica catalysts were characterized through N2 adsorption, XRD, CO2-temperature-programmed desorption, and XRF. Cs-mesoporous silica prepared by the direct incorporation method showed higher catalytic performance than a Cs/MCM-41 catalyst by impregnation method for the catalytic decomposition of sulfone compounds produced from ODS process.

Catalytic Removal of Sulfur Dioxide from Dibenzothiophene Sulfone Over Mg-Al Mixed Oxides Supported on Mesoporous Silica

Dibenzothiophene sulfone (DBTS), one of the products of the oxidative desulfurization of heavy oil, can be removed through extraction as well as by an adsorption process. It is necessary to utilize DBTS in conjunction with catalytic cracking. An object of the present study is to provide an Mg-Al-mesoporous silica catalyst for the removal of sulfur dioxide from DBTS. The characteristics of the Mg-Al-mesoporous silica catalyst were investigated through N2 adsorption, XRD, ICP, and XRF. An Mg-Al-mesoporous silica catalyst formulated in a direct incorporation method showed higher catalytic performance compared to pure MgO during the catalytic removal of sulfur dioxide from DBTS. The higher dispersion of Mg as well as the large surface area of the Mg-Al-mesoporous silica catalyst strongly influenced the catalyst basicity in DBTS cracking.

Nature and Location of Copper Nanospecies in Mesoporous Molecular Sieves

Copper-mesoporous molecular sieves type MCM-41 have been successfully prepared by different direct incorporation methods of the metal in the initial synthesis gel. Various techniques including XRD, AAS, adsorption/desorption of N2, UV−vis−DR, TPR, and XPS were employed for the materials characterization. All of the materials exhibited a good structural regularity, even for loadings of copper of ∼10 wt %, besides high specific surface areas and pore volumes. An extended and detailed study about the nature of copper oxidation state as well as of the copper species distribution on the siliceous nanostructure has been made. It was found that copper is present on the mesoporous silica in the form of various species: isolated mononuclear Cuδ+ cations possibly in coordination with the lattice oxygen; linear oligonuclear [Cuδ+···Oδ−···Cuδ+]n clusters probably inserted into mesoporous channels; and bulky CuO oxide segregated of the structure. The distribution of copper species in the final solid depends on the preparation method used as well as of the copper content in the initial gel. Moreover, we infer the coexistence of the both copper oxidation states +1 and +2 (+δ) in the major species of these materials: isolated and oligonuclear copper species.

Validation of a computational method for assessing the impact of intra-fraction motion on helical tomotherapy plans

In this work, a method for direct incorporation of patient motion into tomotherapy dose calculations is developed and validated. This computational method accounts for all treatment dynamics and can incorporate random as well as cyclical motion data. Hence, interplay effects between treatment dynamics and patient motion are taken into account during dose calculation. This allows for a realistic assessment of intra-fraction motion on the dose distribution. The specific approach entails modifying the position and velocity events in the tomotherapy delivery plan to accommodate any known motion. The computational method is verified through phantom and film measurements. Here, measured prostate motion and simulated respiratory motion tracks were incorporated in the dose calculation. The calculated motion-encoded dose profiles showed excellent agreement with the measurements. Gamma analysis using 3 mm and 3% tolerance criteria showed over 97% and 96% average of points passing for the prostate and breathing motion tracks, respectively. The profile and gamma analysis results validate the accuracy of this method for incorporating intra-fraction motion into the dose calculation engine for assessment of dosimetric effects on helical tomotherapy dose deliveries.

Resistance training alters the response of fed state mixed muscle protein synthesis in young men

Ten healthy young men (21.0 +/- 1.5 yr, 1.79 +/- 0.1 m, 82.7 +/- 14.7 kg, means +/- SD) participated in 8 wk of intense unilateral resistance training (knee extension exercise) such that one leg was trained (T) and the other acted as an untrained (UT) control. After the 8 wk of unilateral training, infusions of L-[ring-d(5)]phenylalanine, L-[ring-(13)C(6)]phenylalanine, and d(3)-alpha-ketoisocaproic acid were used to measure mixed muscle protein synthesis in the T and UT legs by the direct incorporation method [fractional synthetic rate (FSR)]. Protein synthesis was determined at rest as well as 4 h and 28 h after an acute bout of resistance exercise performed at the same intensity relative to the gain in single repetition maximum before and after training. Training increased mean muscle fiber cross-sectional area only in the T leg (type I: 16 +/- 10%; type II: 20 +/- 19%, P < 0.05). Acute resistance exercise increased muscle protein FSR in both legs at 4 h (T: 162 +/- 76%; UT: 108 +/- 62%, P < 0.01 vs. rest) with the increase in the T leg being significantly higher than in the UT leg at this time (P < 0.01). At 28 h postexercise, FSR in the T leg had returned to resting levels; however, the rate of protein synthesis in the UT leg remained elevated above resting (70 +/- 49%, P < 0.01). We conclude that resistance training attenuates the protein synthetic response to acute resistance exercise, despite higher initial increases in FSR, by shortening the duration for which protein synthesis is elevated.