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Flat peach fruit are cold-sensitive and vulnerable to chilling injury (CI), particularly internal browning (IB) during cold storage, which limits the consumer acceptance and market value of the fruit. Controlled atmosphere (CA) has been used to alleviate IB in fruit. However, the mechanisms of CA on IB in peach remains unknown. This study investigated the effects of CA (3-3.5% Oxygen, 3-3.5% Carbon dioxide, and 93-94% nitrogen) treatment on IB development, sugar metabolism, and energy metabolism in cold-stored (1 ± 0.5 °C) peach. The CA treatment effectively inhibited the development of IB and markedly inhibited the reduction of sugar contents and energy charge. The protein expression of the V-type proton ATPase subunit was significantly inhibited by the CA treatment, accompanied by higher adenosine triphosphate (ATP) content, and energy charge than the control fruit. Notably, the expressions of the pyruvate kinase family of proteins, pyruvate decarboxylases, and sucrose synthase were induced by CA treatment that had complex protein interactions with the ATPase and the energy metabolism pathway. These results indicated that CA treatment enhanced the chilling tolerance attributed to maintaining higher levels of energy status and sugar contents by regulating the expression of key proteins involved in energy metabolism during cold storage and shelf life. Taken together, our study can provide theoretical support for the research and development of fresh-keeping and cold-chain logistics technology.

SUMMARY Axillary web syndrome (AWS) is a self-limiting disease that can occur as an early or possibly late postoperative complication post-axillary surgery. This syndrome is characterized by the spread of the cords of subcutaneous tissue extending from the axilla into the arm and is clinically associated with pain and limited movement of the shoulder in the affected limb. Although its pathophysiology is not well established, the most common cause is surgery-related axillary lymphatic injury. Both the echography and magnetic resonance imaging results support the lymphatic hypothesis. The diagnosis of AWS is based on physical examination. Risk factors may include extensiveness of surgery, younger age, hypertension, lower body mass index, ethnicity, and healing complications. Effective clinical intervention shortens the natural course of AWS and improves the quality of life of patients with AWS. Treatments may include physical therapy, drug therapy, manual drainage, instrument-assisted soft tissue mobilization (IASTM), thoracic manipulation and stretching, manual axial distraction, percutaneous needle cord disruption with fat grafting and Xiaflex injection, and surgical intervention. Routine surgical treatment for AWS may not be recommended. Further research is needed to provide more comprehensive improvements in the diagnosis and treatment of AWS.

Carbon nanotubes (CNTs) reinforced polymer composites are highly desirable as ideal candidates of light-weighting structural and multifunctional materials due to their potential to combine the superior performance of individual constituents. However, the development of polymer/CNTs composites remains limited due to the long-standing issues on manufacturing challenge to achieve uniform dispersion of nanoscale filler, and the rapid ascent of the viscosity induced by the high-aspect-ratio CNTs. In this work, ionic liquid-like MWCNTs (MWCNTs-iL), which have high densities of covalently grafted organic moieties and keep liquid state at room temperature, are introduced into epoxy matrix. Since the compatibility of MWCNTs-iL and the epoxy matrix is efficiently improved, the epoxy/MWCNTs-iL composites exhibit homogeneous dispersion and 69.1% shear viscosity reduction compared to traditional epoxy/MWCNTs composites with 8 wt% loading of MWCNTs. MWCNTs-iL with stiff nanotube core and soft polyether shell play the simultaneous reinforcing and toughening roles in epoxy-based composites. Additionally, the influences of the MWCNTs defect concentration on the electrical and thermal conductive properties of epoxy-based composites as a function of filler contents are also investigated.

Most animals have established the mutualistic interactions with their intestinal microbes which provide multiple benefits to their host physiology. However, the mechanisms behind hosts determine the load and composition of gut microbiota are still poorly understood outside dipteran insects. Here, the gene, encoding the NF-κB-like transcription factor Relish, being designated as RfRelish, was identified and analyzed in red palm weevil (RPW), Rhynchophorus ferrugineus Olivier. We revealed that the abundance of RfRelish transcripts in the fat body, hemolymph and gut are significantly higher than that in non-immunity-related tissues, and its expression level can be markedly induced by bacterial challenges. When RfRelish was silenced, the ability of individuals to clear the pathogenic bacteria in body cavity and gut was significantly compromised, suggesting that both the systemic and gut local immunity were impaired dramatically by RfRelish knockdown. Additionally, the silenced insects exhibited increased gut bacterial load, and the relative abundance of some gut bacteria was changed as compared to controls. Collectively, our findings demonstrate that the IMD-like pathway restricts the proliferation of gut bacteria and shapes the commensal community structure in the intestine of R. ferrugineus by mediating the secretion of antimicrobial peptides. We provide a striking example on how an insect pest maintains the homeostasis of gut microbiota via a conserved immune pathway without compromising the advantages of the mutualistic relationships.

Polymer-based thermal conductive composites (PTCs) with good thermal and mechanical properties are highly appreciated in the thermal management of modern electronic devices. However, the heat transfer property of particle-filled PTCs is severely limited by the thermal resistance at both filler-matrix and filler-filler interfaces. Intensive efforts have been taken to enhance the filler-matrix interface, however, the effect of filler-filler thermal contact resistance on the heat transfer properties of PTCs is still not very clear. In this work, continuous thermal conductive networks with good filler-filler interface contact are formed in epoxy composites via the in-situ sintering of silver nanoparticles on the surface of boron nitride nanosheets (BNNS). In this composites, homogeneously dispersed and well exfoliated BN nanosheets are bridged to each other via the sintered AgNPs located at the BNNS and a 3D boron nitride nanosheets network is formed with solid Ag junctions lying in between. After thermal sintering process, the thermal conductivity of EP/BNNS@AgNPs composite with the 3D boron nitride nanosheets network increase from 0.95 W/m·K to 1.13 W/m·K at the filler loading of 20 wt%, which indicates that merged AgNPs are used as thermal transport junctions to reduce the thermal contact resistance within 3D BNNS networks. The present strategy provides an effective route for developing high-performance PTCs.

The use of reduced graphene oxide (rGO) in high-temperature oxidization (HTO) environment, is limited by its poor thermal oxidation and fire resistance. In this study phosphorus and nitrogen co-doped reduced graphene oxide (PN-rGO) with high oxidation and fire resistance was prepared by hydrothermal and microwave treatment and its thermal oxidation decomposition kinetics and mechanisms were analyzed. Concisely, PN-rGO presents an increment of 162 °C in the decomposition temperature relative to undoped rGO (WrGO), and excellent fire resistance with only a ∼20% mass loss after burning. Thermal oxidation degradation kinetics reveals that WrGO shows continuously increasing activation energy (E) within a range of 119.7–182.9 kJ/mol, while PN-rGO exhibits almost constant E of ∼171.8 kJ/mol during main degradation stage. Moreover, the improved E at initial stage by phosphorus/nitrogen doping, combining with the char analysis, suggested that the introduction of strong chemical bonds replacing the reactive oxygen-containing groups was the key to preventing the oxidation of rGO. As one of the main properties, the electrical conductivity of PN-rGO is well kept after HTO treatment. This work demonstrates that a doping strategy can effectively expand the application of graphene-based devices in HTO environment.

In this study, epoxy (EP)/binary spherical alumina (S-Al2O3) composites with a high loading of 50 vol% were fabricated by incorporating different sizes of S-Al2O3 into EP to increase the thermal conductivity and yet retain the flowability of the composites. Notably, a distinctly reduced viscosity (21.8 Pa·s) and a highly increased thermal conductivity (1.364 W/m·K) were achieved by a binary S-Al2O3 mixture with 80% 30 μm and 20% 5 μm alumina that would have a theoretical maximum packing volume, thus permitting larger available free volume for the motion of particles and hence reducing the friction between them. Also, these EP/S-Al2O3 binary composites possessed superior electrical insulation, high thermal stability, significantly reduced thermal expansion coefficient and good mechanical properties. These combined desirable properties indicate that binary S-Al2O3 mixtures with an optimized size distribution and maximum packing volume are best candidates to develop high-performance epoxy-based underfill materials which would improve the flip-chip reliability.

Crosslinked polymer electrolyte (CPE) and composite polymer electrolyte are two of the most promising polymer electrolyte (PE) systems for improving the resistance to Li dendrite growth, but the trade-off and agglomerated effects of these PEs hinder the development of safe Li metal battery (LMB). Herein, a new class of crosslinked composite polymer electrolyte (CCPE) with the combination of confined ionic liquid (IL) polymer network and homogeneously dispersed boron nitride nanosheet (BNNS) for LMB is reported. This UV-curable CCPE is formed on electrode via in-situ crosslinking of a precursor solution in a rapid and solvent-free step, and the assembly process of LMBs and interfacial contact/adhesion are maximum optimized. The critical point of this CCPE is that a facile channel for Li+ transfer and a robust skeleton for confining IL and strengthening interface are simultaneously achieved via the introduction of network structure and 2D BNNS in PE. Consequently, the LiFePO4ǀLi batteries involving CCPE show a great improvement in the charge-discharge cycling stability and rate performance compared with those of the cells with pure CPE. This study offers an effective and facile strategy for fabricating dendrite-resistant CCPE with potential applicability in next-generation energy storage systems.

Uncontrollable lithium (Li) dendrite growth has hampered the application of lithium metal batteries (LMBs). Herein, a novel plastic crystal composite polymer electrolyte (nh-CPE) consisting of multifunctional two-dimensional (2D) molybdenum disulfide (MoS2) and ion-conducting one-dimensional (1D) surfactant oxidized cellulose nanocrystal (OCNC) is developed to overcome this challenge. The nh-CPE possesses good Li-dendrite-suppressing ability, which is attributed to the well-designed three-dimensional (3D) ion conducting network constructed by homogeneously dispersed MoS2 and OCNC. This structure facilitates Li-ion conductivity and enables uniform Li deposition on the anode. Moreover, the impermeable MoS2 nano-flakes with excellent mechanical strength serve as physical barriers to hold the electrolyte-electrode interface stability and consequently block Li dendrite growth and enhance fire retardancy. When applied in LMB, the nh-CPE exhibits excellent cycle performance and rate capability, with 90% capacity retention after 200 cycles at 0.5 C and 60 °C, and a discharge capacity of 128 mAh g−1 at 1 C. Notably, owing to high room-temperature ionic conductivity (0.8 mS cm−1), the cell with nh-CPE cycled at room temperature delivers an initial discharge capacity of 144 mAh g−1. The outstanding performance and simple process offer great opportunity to promote Li-dendrite-suppressing LMBs for practical application.

The illumination uniformity of incubators used for growing edible mushrooms has an important influence on the accuracy of extracted light formula. To design a light emitting diode (LED) array with uniform illumination, we study the influence of number of LEDs, luminous half angle and the position on the two-dimensional plane by using the genetic algorithm. Numerical results show that the illumination uniformity of optimized LED array can reach up to 97%, which is superior to those of traditional rectangular, elliptical and triangular LED arrays. Finally, simulation results obtained from TracePro software verify that accuracy of numerical calculations.

In this study, surface helium (He) effect on hydrogen isotopes diffusion and trapping/detrapping behavior was modelled and integrated into the HIDT simulation code. Effective dynamics properties of hydrogen in tungsten including diffusivity, solubility, recycling and diffusion barrier were considered to reflect the influence of He bubbles. Simulation results showed that total hydrogen retention was reduced with the existence of He bubbles near surface, which was consistent with the reported laboratory experimental results. It was found that the most significant influence came from the diffusion barrier induced by He bubbles. With increasing the barrier factor, total hydrogen retention changed from the tendency of decrease to increase. When the barrier factor was less than 0.3, hydrogen desorption from the implantation surface was dominant, while that from the backside surface became dominant when the barrier factor was greater than 0.4. In the meanwhile, more hydrogen accumulated beyond the He bubble layer was observed. These hydrogen atoms occupied not only in trapping sites, but also in lattice sites. Based on these findings, three desorption stages, namely surface desorption, major desorption and backside desorption, could characterize the TDS spectra with different mechanisms. In addition, our findings were further substantiated by the reported experimental data. This study provides a new perspective to reveal the surface He effect on hydrogen isotopes retention behavior in plasma facing materials.

Ethanol is used as a gasoline blending component in numerous countries throughout the world. In the present work, the Chemkin Pro package was used to study the chemical kinetic behavior of E30 (a blended fuel containing 30% ethanol and 70% gasoline on volume basis). The effects of chemical kinetics and adiabatic flame temperature on the laminar flame propagation speed at different initial temperatures were studied and the relative importance of the thermal and chemical effects of ethanol at different initial temperatures was investigated. With increasing initial temperature, the rate of main branching reactions (R1:O2 + H ⇔ O + OH and R29: CO + OH ⇔ CO2 + H) increases much more than that of the main termination reactions (R13:H20 + M ⇔ H + OH + M, R15:O2 + H(+M) ⇔ HO2(+M)). The laminar flame propagation speed shows a linear relationship with the sum of the peak concentrations of H and OH. The chemical effect of ethanol was far greater than its thermal effect which was characterized by adiabatic flame temperature. In addition, the cellular instabilities of the E30-Air flame were studied. As the initial pressure and equivalence ratio change, the dominant instability shifts between hydrodynamic and diffusional-thermal. The theoretical critical Peclet number (Pecr) decreases with increased equivalence ratio and is insensitive to the initial temperature and pressure; these trends are consistent with the experimental findings. Furthermore, β ( Le eff - 1 ) Pe ( σ - 1 ) Q2 is the dominant parameter affecting Pecr with varying equivalence ratio.

Biomimetic materials based on eco-friendly polymers are increasingly becoming new functional materials for their superior engineering performances in practical applications and are promising to replace the traditional petroleum-derived plastics. Among the reported assembly processes, methods to construct highly aligned structures often involve complicated steps, while those simple processing methods can’t achieve desired orientation degree. Inspired by nature, we show a facile method to construct stem-like composites by mechanical inducing self-assembly method through shape memory effects of poly(propylene carbonate) (PPC). Silicon carbide nanowires (SiCNWs) are orderly aligned in the PPC matrix during the stretching process and also act as physical netpoints to maintain the highly aligned structure of the composites. Benefit from the unique stem-like structure, the resultant PPC/SiCNWs composites not only possess superior thermal conductivity, good shape memory properties but also display much higher tensile strength and ductility properties compared with those random SiCNWs enhanced PPC nanocomposites. Such a construction method has no size restriction or fundamental barrier for further scale-up and can be easily extended to other composites with aligned reinforcing agents of 1D or 2D nanofillers, providing a new strategy for the rational design of high-performance biomimetic composites in an efficient and sustainable way.

Lithium metal is a promising anode material for rechargeable batteries with high energy density. However, the uncontrollable dendrite growth severely hinders the commercialization of Li metal anode. Inspired by the “leveling” mechanism in traditional electroplating, we demonstrate that boron nitride nanosheets (BNNSs) as a liquid electrolyte additive can level out Li protrusions and enable dendrite-free Li metal anodes. 2D BNNSs can automatically and continuously flatten Li deposits and accommodate volume changes during Li plating/stripping. B atoms in BNNS as Lewis acid sites interact with Lewis basic anions in electrolyte, reducing Li+ concentration gradient and unifying Li deposition. The collect effects of BNNS additive give rise to dendrite-free Li anodes over 400 h and deep plating/stripping up to 35 mAh cm−2, as well as potential application in sub-zero temperature batteries (−20 °C). Li–S full cells using BNNS electrolyte also exhibit improved performance. This simple and effective strategy is applicable to develop dendrite-free Li or other metal anodes in high-performance energy storage devices.

Online measurement of carbon content of coal is important for coal-fired power plants to realize the combustion optimization of coal-fired boilers. Given that the measurement of carbon content of coal using laser-induced breakdown spectroscopy (LIBS) suffers from low measurement accuracy because of matrix effects, our previous study has proposed a combination model to improve the measurement accuracy of carbon content of coal. The spatial confinement method, which utilizes the spectral emissions of laser-induced plasmas spatially confined by cavities for quantitative analysis, has potential to improve quantitative analysis performance. In the present study, the combination model was used for coal measurement with cylindrical cavity confinement to further improve the measurement accuracy of carbon content of coal. Results showed that measurement accuracy was improved when the combination model was used with spatial confinement method. The coefficient of determination, root-mean-square error of prediction, average relative error, and average absolute error for the combination model with cylindrical cavity confinement were 0.99, 1.35%, 1.66%, and 1.08%, respectively, whereas values for the combination model without cylindrical cavity confinement were 0.99, 1.63%, 1.82%, and 1.27%, respectively. This is the first time that the average absolute error of carbon measurement for coal analysis has achieved close to 1.0% using LIBS, which is the critical requirement set for traditional chemical processing method by Chinese national standard. These results indicated that LIBS had significant application potential for coal analysis.

Solder joint integrity has long been recognized as a key issue affecting the reliability of integrated circuit packages. In this study, both experimental and finite element simulation methods were used to characterize the mechanical performance and fracture behavior of micro-scale ball grid array (BGA) structure Cu/Sn–3.0Ag–0.5Cu/Cu solder joints with different standoff heights (h, varying from 500 to 100 μm) and constant pad diameter (d, d = 480 μm) and contact angle under shear loading. With decreasing h (or the ratio of h/d), results show that the stiffness of BGA solder joints clearly increases with decreasing coefficient of stress state and torque. The stress triaxiality reflects the mechanical constraint effect on the mechanical strength of the solder joints and it is dependent on the loading mode and increases dramatically with decreasing h under tensile loading, while the change of h has very limited influence on the stress triaxiality under shear loading. Moreover, when h is decreased, the concentration of stress and plastic strain energy along the interface of solder and pad decreases, and the fracture location of BGA solder joints changes from near the interface to the middle of the solder. Both geometry and microstructure greatly affect the shear behavior of joints, the average shear strength shows a parabolic trend with decreasing standoff height. Furthermore, the brittle fracture of BGA solder joints after long-time isothermal aging was investigated. Results obtained show that, under the same shear force, the stress intensity factors, KI and KII, and the strain energy release rate, GI, at the Sn–3.0Ag–0.5Cu/Cu6Sn5 interface and in the Cu6Sn5 layer obviously decrease with decreasing h, hence brittle fracture is more prone to occur in the joint with a large standoff height.

The ZnO-B 2 O 3 -SiO 2 glass doped with Nd 2 O 3 and Gd 2 O 3 was prepared by high temperature melt cooling method. The standard sample of the zinc borosilicate glass was placed in the constant temperature and humidity chamber in order to simulate the atmospheric corrosion process. The surface of the weathered glass was analyzed by scanning electron microscope and energy dispersive spectrometry and the filtrate was analyzed by inductively coupled plasma-atomic emission spectrometry. The results showed that humidity was the most important factor influencing weathering; the morphology of glass surface of altered layer and the product on the surface was observed; the corroding degree of the zinc borosilicate glass doped with Nd or Gd was significantly lighter than that of the base glass. Adding rare earth Nd or Gd in the zinc borosilicate glass could suppress Na, Zn, Si ion release in weathering.

Successful quantitative measurement of carbon content in coal using laser-induced breakdown spectroscopy (LIBS) is suffered from relatively low precision and accuracy. In the present work, the spectrum standardization method was combined with the dominant factor based partial least square (PLS) method to improve the measurement accuracy of carbon content in coal by LIBS. The combination model employed the spectrum standardization method to convert the carbon line intensity into standard state for more accurately calculating the dominant carbon concentration, and then applied PLS with full spectrum information to correct the residual errors. The combination model was applied to the measurement of carbon content for 24 bituminous coal samples. The results demonstrated that the combination model could further improve the measurement accuracy compared with both our previously established spectrum standardization model and dominant factor based PLS model using spectral area normalized intensity for the dominant factor model. For example, the coefficient of determination (R2), the root-mean-square error of prediction (RMSEP), and the average relative error (ARE) for the combination model were 0.99, 1.75%, and 2.39%, respectively; while those values for the spectrum standardization method were 0.83, 2.71%, and 3.40%, respectively; and those values for the dominant factor based PLS model were 0.99, 2.66%, and 3.64%, respectively., Keywords: LIBS; Coal; Standardization; PLS; Quantitative analysis.8 pages;4 figures

Silt is a widespread deposit in the lower reaches of the Yellow River, China with low plasticity and cohesion and poorly-graded characteristics. It is the primary filling material for subgrades in this region because of the lack of sand and gravel materials. Using the California Bearing Ratio (CBR) method alone to characterize the silt subgrade cannot provide an adequate assessment of its shear behaviors under monotonic and repeated loading. To improve the understanding of the strength and deformation characteristics of silt fill, a series of triaxial tests under monotonic and repeated loading were conducted. Specifically, the variations in the engineering characteristics (such as shear strength, permanent deformation, resilient modulus, and threshold stress) of silt fill caused by changes in the physical and stress states were investigated. Experimental results were used to establish empirical correlations for the strength and deformation parameters. These results provide a basis for the mechanical analysis and design of silt subgrades for stability.

Carbon nanotubes reinforced polymer composites with high thermal conductivity show attractive prospects as multifunctional thermal management materials for high-power electronics applications. The contradictory relationship between homogenous filler dispersion with enhanced interfacial interaction and the intrinsic properties of embedded filler, usually leads to the uncertainty and low thermal conductivity improvement efficiency of resulting polymer composites. Herein, noncovalently functionalized multi-walled carbon nanotubes with imidazolium amine-terminated ionic liquids (AIL-MWCNTs) were facilely prepared through cation-π stacking interactions and acted as low-defect fillers for improving the thermal conductivity of epoxy. The mild chemical modification process has considerable advantages for reserving the inherent intact structures of MWCNTs. Hence, the thermal conductivity enhancement of EP/AIL-MWCNTs composite (∼211%) is much higher than that of epoxy composite filled with acidified MWCNTs (∼102%) at 8 wt% loading. The noncovalent functionalization approach is a promising strategy for scalable fabrication of MWCNTs-based polymer composite with simultaneously enhanced thermal conductivity and mechanical properties.

In this work, thermal ageing of the reduced activation ferritic/martensitic steel CLF-1 with a nitrogen content of 0.025% has been performed at temperatures of 823 K and 873 K for 6000 h. Mechanical properties (hardness, tensile and Charpy impact) and microstructure characterisation has been carried out. After thermal ageing treatments, the steels showed similar values of hardness and tensile properties and a slight deterioration of impact properties were observed. After long term thermal ageing, the M23C6-type precipitation coarsens and agglomerates along lath and grain boundaries. Compared with steels that have lower nitrogen content, the coarsening and agglomeration of M23C6 in the steels with higher nitrogen content is much lower and the steel shows higher microstructural stability. (C) 2013 Elsevier B. V. All rights reserved.

A bottleneck of the wide commercial application of laser-induced breakdown spectroscopy (LIBS) technology is its relatively high measurement uncertainty. A partial least squares (PLS) based normalization method was proposed to improve pulse-to-pulse measurement precision for LIBS based on our previous spectrum standardization method. The proposed model utilized multi-line spectral information of the measured element and characterized the signal fluctuations due to the variation of plasma characteristic parameters (plasma temperature, electron number density, and total number density) for signal uncertainty reduction. The model was validated by the application of copper concentration prediction in 29 brass alloy samples. The results demonstrated an improvement on both measurement precision and accuracy over the generally applied normalization as well as our previously proposed simplified spectrum standardization method. The average relative standard deviation (RSD), average of the standard error (error bar), the coefficient of determination (R 2 ), the root-mean-square error of prediction (RMSEP), and average value of the maximum relative error (MRE) were 1.80%, 0.23%, 0.992, 1.30%, and 5.23%, respectively, while those for the generally applied spectral area normalization were 3.72%, 0.71%, 0.973, 1.98%, and 14.92%, respectively.

In this letter, novel optical switches based on VO2 thin film on substrates of silicon (1 0 0) has been fabricated. The vanadium dioxide thin films were deposited by reactive ion beam sputtering followed by a post-annealing. Testing shows the insertion loss of the optical switches is 1–2 dB, and the extinction ratio up to 26 dB. The speed of the switches is as fast as 3 ms.

Microbolometers with 128-linear array utilizing VOx thin films as thermal sensitive material were fabricated using micromachining technology. In order to obtain thermosensitive material with high quality and low cost, a new deposition method of VOx thin film was described in this paper. The process of the new method was compatible with Si micromachining and CMOS technology, which was very important for monolithic integration with CMOS readout circuit. The responsivity and the detectivity of microbolometers were tested to be about 5 kV/W and 2 × 108 cm Hz1/2 W−1 at current bias of 100 μA, respectively.

In recent years microspheres or microparticles produced from biodegradable polymers such as poly( d,l -lactide) (PLA) and poly( d,l -lactide-co-glycolide) (PLGA) containing encapsulated vaccine antigens have been investigated for administration via parenteral, oral, and intranasal routes. These microparticles allow the controlled release of vaccines with an aim to reduce the number of doses for primary immunisation or to develop single dose vaccines. The polymer materials have been widely regarded as being of minimal toxicity. Evaluation of candidate systems in animal studies have shown antibody levels and cell responses similar to or greater than those observed with adjuvants such as alum. However, there are concerns regarding the integrity and immunogenicity of the antigen during the encapsulation process when the antigen is exposed to organic solvents, high shear stresses and the exposure of antigen to low pH which is caused by polymer degradation. An alternative approach would be to adsorb antigens to the surface of biodegradable polymer particles. Polymeric lamellar substrate particles (PLSP), produced by a simple precipitation of PLA, are suitable for this purpose. The adsorption of antigens onto these particles is a simple procedure. It avoids pH changes due to bulk polymer degradation and the use of solvents and therefore will be less damaging to the vaccine. Moreover, such systems will be much easier to scale up for a clinical study and eventual manufacture. The aim of this article is to discuss the preparation and physical characteristics of PLSP, antigen adsorption, in vivo efficacy of PLSP antigen systems and to consider the potential of PLSP as controlled release adjuvants for protein, peptide or viral vaccines.