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To effectively extract biogenic amines (BAs) from complex food matrices is an important issue. In this study, a stop-and-go-extraction tip (StageTip)-based method for simultaneous enrichment of six BAs including histamine, tyramine, putrescine, cadaverine, tryptamine, and β-phenylethylamine in fish samples was developed and optimized. This StageTip-based BAs extraction method required short extraction time, small sample size, and minimal consumption of organic solvents. In addition, an ultrahigh-performance liquid chromatography coupled with triple quadrupole mass spectrometer was used to identify and quantify BAs without derivatization. Target recovery efficiencies of BAs from spiked fish samples ranged from 84% to 110%. Linear regression models were established to determine BAs in the range of 0.4 to 3.0 mg/L (R2 > 0.995). Good repeatability was obtained with relative standard deviation of peak areas (1.17 to 5.61%) and retention time (0.09 to 0.20%). High sensitivity was achieved for the detection of six BAs (0.064 to 1.00 ng/L for the limit of detection, 0.10 to 5 ng/L for the limit of quantification). The proposed method had an obvious advantage in the analysis of BAs in complex food matrices such as fish tissues since it could reflect the subtle distribution of BAs from one fish fillet. PRACTICAL APPLICATION: A StageTip-based BAs enrichment combined with UPLC-MS analysis method was developed and optimized, which was low-cost, environmentally friendly, and with good analytical performances. As such, it has the potential to become a powerful tool for the analysis of BAs in different complex food matrices.

Different heating conditions could change water absorption capacity of sea cucumbers body wall (SCBW), and subsequently affect the sensory quality of the rehydrated sea cucumbers. In this study, fresh SCBWs were boiled for 30, 60, 90, 120, 150, 180 min, respectively. The boiled SCBWs were then soaked in deionized water for 48 hr. The changes in water absorption ratio (W

The combined effects of aging and low temperature, long time heating (LTLT) on meat toughness were investigated. Pork loins were heated at 53 or 58 °C for up to 20 h, and shear force values, cooking loss, moisture content, collagen solubility, electrophoresis of myofibrillar proteins were determined. Structural changes in perimysium were also observed by light microscopy and scanning electron microscopy (SEM). Results showed that aging and LTLT cooking independently affected meat toughness, and higher temperature or longer time were required to decrease toughness of one-day aged meat to the same level as in 10-day aged meat. Collagen solubilization is suggested as the main reason for the tenderization effect of LTLT. Myofibrillar proteolysis might not occur during LTLT cooking, and will not be contributing to meat tenderness.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by accumulation of misfolded α-synuclein within the central nervous system (CNS). Visual problems in PD patients are common, although retinal pathology associated with PD is not well understood. The purpose of this study was to investigate retinal pathology in a transgenic mouse model (TgM83) expressing the human A53T α-synuclein mutation and assess the effect of α-synuclein “seeding” on the development of retinal pathology. Two-month-old TgM83 mice were intracerebrally inoculated with brain homogenate from old (12–18 months) TgM83 mice. Retinas were then analyzed at 5 months of age. We analyzed retinas from 5-month-old and 8-month-old uninoculated healthy TgM83 mice, and old (12–18 months) mice that were euthanized following the development of clinical signs. Retinas of B6C3H mice (genetic background of the TgM83 mouse) served as control. We used immunohistochemistry and western blot analysis to detect accumulation of α-synuclein, pTauThr231, inflammation, changes in macroautophagy, and cell death. Raman spectroscopy was used to test the potential to differentiate between retinal tissues of healthy mice and diseased mice. This work demonstrates retinal changes associated with the A53T mutation. Retinas of non-inoculated TgM83 mice had accumulation of α-synuclein, “pre-tangle” tau, activation of retinal glial cells, and photoreceptor cell loss by 8 months of age. The development of these changes is accelerated by inoculation with brain homogenate from clinically ill TgM83 mice. Compared to non-inoculated 5-month-old TgM83 mice, retinas of inoculated 5-month-old mice had increased accumulation of α-synuclein (pSer129) and pTauThr231 proteins, upregulated microglial activation, and dysregulated macroautophagy. Raman spectroscopic analysis was able to discriminate between healthy and diseased mice. This study describes retinal pathology resulting from the A53T mutation. We show that seeding with brain homogenates from old TgM83 mice accelerates retinal pathology. We demonstrate that Raman spectroscopy can be used to accurately identify a diseased retina based on its biochemical profile, and that α-synuclein accumulation may contribute to accumulation of pTauThr231 proteins, neuroinflammation, metabolic dysregulation, and photoreceptor cell death. Our work provides insight into retinal changes associated with Parkinson's disease, and may contribute to a better understanding of visual symptoms experienced by patients.

Fluorescent nanoparticles (FNPs) produced from roast meat have drawn widespread attention due to their potential hazards to human health. In this paper, the presence of ultrasmall FNPs in roast duck and their interaction with human serum albumin (HSA) were reported. The processing-induced FNPs have an average size of 1.3 nm with a relative fluorescence quantum yield of 4.4%. X-ray photoelectron spectroscopy showed that the FNPs are composed of carbon (70.48%), nitrogen (6.25%), oxygen (22.17%) and sulfur (1.11%), with hydroxyl, carboxyl and amino groups present on their surface. The presence of FNPs could cause fluorescence quenching of HSA, which was ascribed to the static quenching mechanism via the electrostatic interaction as analyzed by isothermal titration calorimetry. The α-helix contents of HSA decreased after the addition of FNPs, demonstrating that these processing-induced FNPs could cause structural alteration of HSA. These results provided insights into the formation of nanoparticles in roast duck, and offered important information about the binding mechanism of these nanoparticles with HSA, which may have physiological implications.

The intestinal epithelium forms an essential element of the mucosal barrier and plays a critical role in the pathophysiological response to different enteric disorders and diseases. As a major enteric dysfunction of the intestinal tract, inflammatory bowel disease is a genetic disease which results from the inappropriate and exaggerated mucosal immune response to the normal constituents in the mucosal microbiota environment. An intestine targeted drug delivery system has unique advantages in the treatment of inflammatory bowel disease. As a new concept in drug delivery, the Trojan horse system with the synergy of nanotechnology and host cells can achieve better therapeutic efficacy in specific diseases. Here, we demonstrated the feasibility of encapsulating DNA-functionalized gold nanoparticles into primary isolated intestinal stem cells to form an intestinal Trojan horse for gene regulation therapy of inflammatory bowel disease. This proof-of-concept intestinal Trojan horse will have a wide variety of applications in the diagnosis and therapy of enteric disorders and diseases.

Foodborne nanostructures have gained more and more attention in recent years. In this paper, the presence and physicochemical properties of carbonaceous nanostructures (CNSs) from roasted pike eel ( Muraenesox cinereus) were reported. The monodispersed CNSs are strongly photoluminescent under the illustration of ultraviolet (UV) light, with a fluorescent quantum yield of 80.16%, and display excitation-dependent emission behavior. The formation of CNSs is believed to go through a process of morphology evolution, including polymerization, pyrolysis, nucleation, growth, emergence, and blossom. The optical properties of the CNSs were shown to be affected by the roasting temperature. Furthermore, cellular uptake of the CNSs was investigated, and it is shown that the CNSs were clearly absorbed into live cells and were mainly distributed within the cell cytoplasm and not in the cell nucleus. This work is among the very first reports on CNSs present in roasted fish, providing valuable insights into the formation mechanism of such nanostructures and showcasing the biodistribution of these food-originated CNSs in live cells.

Limiting nitrogen supply has been routinely used as the master regulator to direct lipid biosynthesis. However, this strategy does not work with nitrogen-rich substrates, such as Jerusalem artichoke (JA), a fructose-based biomass, while it is difficult to obtain a high carbon-to-nitrogen (C/N) molar ratio. In this study, an alternative strategy to promote lipid accumulation by the oleaginous yeast Trichosporon fermentans CICC 1368 was developed by limiting phosphorous supply, and this strategy was implemented with JA hydrolysate as substrate. We showed that lipid accumulation was directly correlated with the C/P ratio of the culture media for T. fermentans. The time course of cell growth and lipid production was analyzed in a media with an initial C/P ratio of 6342, and the cellular lipid content could reach up to 48.5% of dry biomass. Moreover, JA hydrolysates were used as substrate for microbial lipid accumulation, under high C/P molar ratio condition, lipid yield, lipid content, and lipid coefficient increased by 10, 30, and 34%, respectively. It showed that by limiting phosphorus, the conversion of sugar into lipids can be improved effectively. Limiting phosphorus provides a promising solution to the problem of microbial lipid production with nitrogen-rich natural materials.

Bioinformatics approaches are widely used to evaluate the prospects of novel protein sources in bioactive peptide research. Edible cyanobacteria are considered as potential protein precursors. However, the abundance of unicellular cyanobacterial proteins is largely unknown and highly dynamic according to the cultivation conditions, which need to be considered in this research field. The objective of this work was to evaluate the protein abundance of Arthrospira platensis, as well as to map the bioactive peptide sequences from the high-abundance proteins of the A. platensis proteome.The high-abundance proteins of the A. platensis proteome were identified with a high-performance liquid chromatography-tandem mass spectrometry-based method. A total of 593 proteins were detected and quantified. The occurrence frequency of the bioactive peptides in A. platensis proteome was calculated according to the amino acid sequences via the bioinformatics approaches. Further in silico digested by trypsin, pepsin and chymotrypsin, these proteins liberated 78, 99, and 96 bioactive peptides, respectively. In each case, angiotensin-converting enzyme inhibitors and dipeptidyl peptidase IV inhibitors were enriched.This work will help rationally design the protocols for cyanobacterial cultivation, protein pre-treatment and peptide separation, and further produce more peptides with specific functions. © 2017 Society of Chemical Industry.

Background It is challenging to achieve ultrasensitive and selective detection of waterborne pathogens at extremely low levels (i.e., single cell/mL) using conventional methods. Even with molecular methods such as ELISA or PCR, multi-enrichment steps are needed which are labor and cost intensive. In this study, we incorporated nano-dielectrophoretic microfluidic device with Surface enhanced Raman scattering (SERS) technique to build a novel portable biosensor for easy detection and characterization of Escherichia coli O157:H7 at high sensitivity level (single cell/mL). Results A multiplexing dual recognition SERS scheme was developed to achieve one-step target detection without the need to separate target-bound probes from unbound ones. With three different SERS-tagged molecular probes targeting different epitopes of the same pathogen being deployed simultaneously, detection of pathogen targets was achieved at single cell level with sub-species specificity that has not been reported before in single-step pathogen detection. Conclusion The self-referencing protocol implements with a Nano-dielectrophoretic microfluidic device potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

The objective of this study was to develop a statistical model for predicting egg yolk contamination level in egg white using a spectroscopic method. Eggs that were stored for 0, 0.5, 1.0, 1.5, 2.5, and 6.5 wk at 4 °C were manually processed to cleanly separate the yolk from the white. Egg white samples containing 0–0.5% (w/w) of yolk were prepared by adding yolk to the white and further diluting with the pure egg white. Transmission spectra of samples were acquired at 500 nm wavelength. The optical absorbance of the “contaminated” egg white samples positively correlated with the yolk concentration, and its intensity was affected by the freshness of eggs, egg variety, and measuring temperature. A nonlinear prediction model, or a detection function, was developed using 182 measurements to predict yolk concentration with a known storage time. This highly sensitive method was validated using 102 separate measurements.

Whey protein isolates (WPI) and corn zein protein (CZP) films, embedded with porous silica-coated titanium nano-enhancers (TiO 2 @@SiO 2 ), were prepared and exhibited enhanced antimicrobial functionality. Protein solutions at 5% WPI and 13.5% CZP were amended with 1.5% w/w of TiO 2 @@SiO 2 nano-enhancers and subjected to sonication at 0, 16, 80, and 160 I¼m amplitude prior to casting into films. The effects of sonication on nano-enhancer distribution and the structure and morphology of the resulting films were elucidated by transmission electron microscope (TEM). The surface structure of the films was altered by the presence of nano-enhancers. The nano-enhanced biopolymer films exhibited antimicrobial functionality under sunlight by effectively inhibiting bacterial growth. The nano-enhanced biopolymers can potentially be used to make active antimicrobial surface coatings or packaging films to inhibit or slow down microbial growth during storage.

In this study, a non-invasive method utilizing VIS spectroscopy for rapid and quantitative determination of yolk contamination in egg white was developed. Fresh eggs were obtained from Iowa egg production facilities and were used to prepare 210 egg white samples with various levels of yolk contamination. The simulated yolk contamination levels ranged from 0.001 to 0.1 wt% in egg white (as-is basis), and the samples were subjected to spectroscopic analysis. UV–Vis–NIR spectra (200–860 nm) were acquired for each sample with a spectral resolution of 2 nm. The absorption bands at 430 nm and 378 nm were identified as the most sensitive to the yolk contamination. A quantitative predictive model was developed to correlate the two absorptions to the concentration of yolk contamination. The correlation coefficient of calibration set and validation set are 0.9830 and 0.9769, respectively. The MSE (mean squares error) of calibration set and validation set are 0.0066 and 0.0044%, respectively. The UV–VIS spectroscopy method was demonstrated to be sensitive at as low as 0.001% yolk content. It can potentially become a simple, noninvasive, and rapid and yet highly sensitive routine test as a quality control means for egg processing industry.

This study was designed to explore the temperature effects on bacterial communities and metabolites, as well as their relationships during the fermentation of sour meat, a traditional fermented meat product in the ethnic minority regions of China. Results showed that reduction of pH and increase of lactic acid and free amino acid contents occurred (p 0.05) as the fermentation temperature and time increased, and the tendency was more apparent at higher temperature. During the fermentation, Lactobacillus gradually replaced other genera, and higher the temperature, more rapid was the process. Both the number and amount of volatile organic compounds increased at higher temperatures. Hexanal, benzaldehyde, nonanal, (E,E)-2,4-decadienal, 1-octen-3-ol and octanal were identified as the key volatile organic compounds produced by Lactobacillus in sour meat as main contributors to odor as confirmed by variable importance in the projection analysis. Redundancy analysis and Pearson correlation showed positive correlation between Lactobacillus and desired product characteristics, such as higher content of lactic acid, free amino acids, volatile organic compounds, and lower pH and water activity values, which may represent a better quality and longer shelf life after fermentation at higher temperature. Therefore fermentation at 20 °C and 25 °C are proposed as optimum temperatures for sour meat production.

Undaria pinnatifida sporophyll (U. pinnatifida) is a major byproduct of U. pinnatifida (a brown algae) processing. Its phenolic constituents, phlorotannins, are of special interest due to their intrinsic ability to precipitate proteins. Herein, a high-temperature extraction procedure was used to isolate these biologically active compounds. The heating temperature, heating time, and extraction solvent (ethanol) concentration were examined with response surface analysis to determine the optimal conditions to achieve the maximum extraction rate. The analysis revealed the optimal conditions to be: 170 &deg, C of heating temperature, 5.2 h of heating time, and 52% ethanol concentration for a yield of 10.7 &plusmn, 0.2 mg gallic acid equivalent/g dry weight (GAE/g DW) of sample. Compared to epigallocatechin gallate (EGCG), the extracted phlorotannins displayed higher antioxidant activity on H2O2-induced RAW 264.7 cells with improved efficiency. Furthermore, the compounds exhibited strong anti-inflammatory activity. These findings potentially can be utilized to guide development of novel functional foods and food supplements from sea-originated resources such as brown algae.

Anisotropic nanoparticles (i.e., silver nanocubes) were functionalized with target-specific antibodies and Raman active tags to serve as nanoprobes for the rapid detection of bacteria in a test-in-a-tube platform. A self-referencing scheme was developed and implemented in which surface enhanced Raman spectroscopic (SERS) signatures of the targets were observed superimposed with the SERS signals of the Raman tags. The assessment through the dual signals (superimposed target and tag Raman signatures) supported a specific recognition of the targets in a single step with no washing/separation needed to a sensitivity of 102 CFU/mL, even in the presence of non-target bacteria at a 10 times higher concentration. The self-referencing protocol implemented with a portable Raman spectrometer potentially can become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

Whey protein isolate (WPI) films embedded with TiO 2 @@SiO 2 (porous silica (SiO 2 ) coated titania (TiO 2 )) nanoparticles for improved mechanical properties were prepared by solution casting. A WPI solution of 1.5 wt% TiO 2 @@SiO 2 nanoparticles was subjected to sonication at amplitudes of 0, 16, 80 and 160 μm prior to casting in order to improve the film forming properties of protein and to obtain a uniform distribution of nanoparticles in the WPI films. The physical and mechanical properties of the films were determined by dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), and tensile testing. Water vapor permeability (WVP) measurements revealed that the water vapor transmission rates are slightly influenced by sonication conditions and nanoparticle loading. The DMA results showed that, at high sonication levels, addition of nanoparticles prevented protein agglomeration. The thermal stability of the materials revealed the presence of 3–4 degradation stages in oxidizing the protein films. The addition of nanoparticles strengthens the WPI film, as evidenced by tensile stress analysis. Sonication improved nanoparticle distribution in film matrix; such films can potentially become effective packaging materials to enhance food quality and safety.

An alkaline phosphatase was purified from the gut of sea cucumber Stichopus japonicus by n-butyl alcohol extract, ammonium sulfate precipitation, ion exchange chromatography with diethylaminoethyl cellulose, gel filtration chromatography with Sephacryl S-200 and preparative electrophoresis with polyacrylamide gel electrophoresis. The native enzyme was estimated to be 166 ± 9 kDa and produced a single predominant band corresponding to active enzyme on nondenaturing electrophoresis, but showed 2 bands of 97 and 35 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting that the native enzyme is composed of two dissimilar subunits. The enzyme displayed maximum activity at pH 11 and 40 °C, showing narrow pH stability (pH 10–12) and thermal instability at temperature higher than 30 °C. The activity of the purified alkaline phosphatase was enhanced by Mg2+, whereas inhibited by Zn2+, Ca2+ and EDTA at 1 and 10 mM, suggesting its activity is in a magnesium ion-dependent manner. The product-analog WO42− and product HPO42− showed strong inhibitory effects on the enzyme activity. Using p-nitrophenyl phosphate as substrate, the Vmax and Km values were 24.45 μmol/L min and 5.76 mM, respectively.

In this study, glycogen was extracted from oyster Ostrea talienwhanensis Crosse and used as a model to investigate the structure–activity correlation of polysaccharides. Purified oyster glycogen was characterized by methylation analysis, nuclear magnetic resonance (NMR) spectroscopy and infrared spectroscopy (IR). The oyster glycogen was subsequently sulfated by chlorosulfonic acid–pyridine method, and a C-6 substituted species (SOG) was identified to be the primary sulfated oyster glycogen species by 13C NMR spectroscopy. The molecular weight and sulfate content of the SOG was determined to be 3.2 × 104 g/mol and 33.6%, respectively. Another sulfated oyster glycogen species (SOG1) with C-2 and C-3 substitution was also identified at a lesser amount in the final product. SOG exhibited a much stronger stimulation effect to splenic lymphocyte proliferation than SOG1 in vitro, indicating that the position of sulfate substitution is a major determining factor on the efficacy of sulfated glycogens to stimulate lymphocyte proliferation.

Rapid and accurate evaluation of pollutant contamination in water is one of the key tasks of environmental monitoring. To make onsite assessment feasible, the analytical tools should be easy to operate, with minimal sample preparation needs. Gold nanoparticle (AuNP)-based sensors have the potential to detect toxins, heavy metals, and inorganic and organic pollutants in water rapidly with high sensitivity, and they are expected to play an increasingly important role in environmental monitoring. In this article, the synthesis, fabrication and functionalization of AuNPs are discussed, and the recent advances in the development and application of AuNP-based sensors for the determination of various pollutants contamination in water are reviewed.

Photocatalyst-assisted ammonia pretreatment was explored to improve lignin removal of the lignocellulosic biomass for effective sugar conversion. Corn stover was treated with 5.0-12.5 wt.% ammonium hydroxide, two different photocatalysts (TiO(2) and ZnO) in the presence of molecular oxygen in a batch reactor at 60 °C. Various solid-to-liquid ratios (1:20-1:50) were also tested. Ammonia pretreatment assisted by TiO(2)-catalyzed photo-degradation removed 70 % of Klason lignin under the optimum condition (12.5 % ammonium hydroxide, 60 °C, 24 h, solid/liquid=1:20, photocatalyst/biomass=1:10 with oxygen atmosphere). The enzymatic digestibilities of pretreated corn stover were 85 % for glucan and 75 % for xylan with NH(3)-TiO(2)-treated solid and 82 % for glucan and 77 % for xylan with NH(3)-ZnO-treated solid with 15 filter paper units/g-glucan of cellulase and 30 cellobiase units/g-glucan of β-glucosidase, a 2-13 % improvement over ammonia pretreatment alone.

A new simple maskless fabrication method based on room temperature Bosh process was developed to fabricate silicon nanoforest. After being coated with a layer of Au, the Au-coated silicon nanoforest was converted into a surface-enhanced Raman spectroscopy (SERS) substrate. To further enhance SERS signals, the Au-coated silicon nanoforest was grafted with silver-plate nanoparticles (AgNPs). The SERS substrate was used to detect Escherichia coli as a model strain at 106 CFU/mL, and a Raman signal enhancement factor of ∼106 was achieved without any optimization of the SERS substrate. Multiplexed detection was demonstrated through differentiating R6G and E. coli on the same substrate. Given the simplicity and low-cost of the preparation scheme, and the high enhancement efficiency of this nanoforest-based SERS substrate, it can be potentially used in the field of diagnostic microbiology for the label-free detection of bacterial and viral pathogens, and it is also suitable for detecting and analyzing mixtures of compounds to determine their compositions.

Pepsin-solubilized collagen (PSC) was successfully prepared from the body wall of sea cucumber Stichopus japonicus . Ultraviolet–visible and Fourier transform infrared spectroscopic analyses showed that the PSC was a high-purity collagen that maintained the intact triple-stranded helices. Physical and chemical characterization of the PSC showed a isoelectric point of 4.14, a superior moisture-absorption and retention capacities comparing to glycerol, a minimum solubility at pH 5.0 in 0.5 M acetic acid, and a sharp decrease in solubility in the presence of low concentration of NaCl. The viscosity of PSC was shown to decrease continuously as the temperature was increased. The radical scavenging activity of the PSC was characterized with two model systems: for hydroxyl radicals, the PSC was more active than vitamin C but less active than sulfourea; for 1,1-diphenyl-2-picrylhydrazyl radicals, the PSC was more active than vitamin E.

This paper proposed a rehabilitation training system with electromyography (sEMG) feedback for stroke patients based on ARM embedded system and LabVIEW. The system can achieve real-time acquisition, processing and dualview of multi-channel sEMGs and compute related sEMG parameters including iEMG, RMS, MPF and co-contraction ratio. The system was detected by clinical experiments and related inspection department. The result showed that the system is functional, interactive and in accordance with the relevant standards for medical devices so that it can fully satisfy the clinical demands. In addition, the system can help doctors to master the training state of the patient more effectively in a real-time and quantitative way that is direct to improve the training programs of stroke patients.

The texture and microstructure of edible abalone meats were studied during heat treatments from 50 to 100°C for 60 min. No increase in extractable soluble collagen content was observed below 80°C, but a 9-fold increase was observed at 100°C. SDS-PAGE showed that extractable myosin heavy chains and paramyosin contents reduced significantly at 80°C, and disappeared completely at 100°C. The shear force increased slowly from 50 to 70°C, but relaxed back to the initial level at 100°C. Rapid reduction of hardness was observed at 50°C, minimum hardness was obtained at 100°C. Springness, cohesiveness, chewiness, and resilience were enhanced to maximum levels at 70, 90, 70, and 90°C, respectively. Optical micrographs and transmission electron microscope showed a significant increase of intermyofibrillar gaps at 90°C and broken fibers at 100°C. Results suggested that 80°C might be a suitable temperature to produce ready-to-eat abalone products.

A novel colorimetric nitrite ion sensor was developed utilizing 4-aminothiophenol (4-ATP) modified gold nanorods (GNR). In the presence of nitrite ions, the deamination reaction was induced by heating the 4-ATP modified GNR in ethanol solution, resulting in the reduction of the GNR surface charges, which led to aggregation of GNRs and a colorimetric response that was quantitatively correlated to the concentration of nitrite ions. This simple assay was rapid (

Routine identification of pathogenic microorganisms predominantly based on nutritional and biochemical tests is a time-consuming process, but delay may lead to fatal consequences at times. In this work, nanoparticle-induced nanoSPR enhanced IR spectroscopy was used in conjunction with a background elimination data processing algorithm to directly identify microorganisms in mixed cultures. It was demonstrated that the microbial composition of mixtures of different E. coli strains could be accurately identified using our method, at a concentration level of 103 CFU mL -1 . The procedure was also applied to determine the presence or absence of pathogenic microorganisms in a simple but real food matrix (apple juice). Results indicated that microorganisms in a cocktail of up to eight different species suspended in an apple juice matrix could be accurately identified for its presence or absence.

Multilayered Ge-based chalcogenide waveguides were fabricated on Si substrates by thermal evaporation. Channel waveguides were written in the core layer by inducing photoinduced changes in the refractive index by exposure to bandgap light. Very thin (∼20 nm) Au islands were deposited on the top of the core layer for biological functionalization. FT-IR spectroscopy confirmed that the coating of the films with gold did not have a significant effect on the propagation and penetration of IR evanescent waves through the film. Self assembled monolayers (SAM) were formed on the gold islands via thiol chemistry for biological attachment. Antibody (human IgG, anti-E. coli O157:H7, and anti-Salmonella) complexes were formed on the Au islands via the SAMs. The films functionalized with anti-E. coli O157:H7 and anti-Salmonella antibodies were used to detect E. coli O157:H7 and S. enteriditis through label-free IR fingerprinting. Highly selective detection of bacterial targets was achieved at both the species (E. coli vs. S. enteriditis) and strain level (E. coli O157:H7 vs. E. coli K12). This mid infrared approach demonstrates the use of chalcogenides for biosensor.

A new functionalization procedure was developed to replace cyltrimethylammoniumbromide coating on gold nanorods (GNRs) fabricated through seed-mediated growth with chemically active alkanethiols; antibodies were then attached to the GNRs to yield gold nanorod molecular probes (GNrMPs). The functionalization procedure was shown to minimize nonspecific binding. Multiplex sensing was demonstrated for three targets (goat anti-human IgG, goat anti-rabbit IgG, and goat anti-mouse IgG) through the distinct response of the plasmon spectra of GNrMPs to binding events. Quantification of the plasmonic binding events and estimation of ligand binding kinetics tethered to these nanoscale structures was also demonstrated through a mathematical approach. Evaluation of the experimental and theoretical data yields an affinity constant K(a) = 1.34 x 10(7) M(-1), which was in agreement with the IgG-antiIgG binding affinity reported in the literature. The GNrMP sensors were found to be highly specific and sensitive with the dynamic response in the range between 10(-9) M and 10(-6) M. The limit of detection of GNrMPs was found to be in the low nanomolar range, and is a function of the binding affinity: for a higher probe-target affinity pair, the limit of detection can be expected to reach femto molar levels. This technique can play a key role in developing tunable sensors for sensitive and precise monitoring of biological interactions.

Gold nanorod molecular probes (GNrMPs) were designed and fabricated for multiplex identification of cell surface markers in HBECs. Cells were probed directly using dark field microscopy integrated with a spectral imager for simultaneous detection of up to three surface markers. The immunophenotype composition of these cell lines indicative of their metastasis potential was assessed using the GNrMPs. The technique has the potential to become an important tool for diagnosis and prognosis of breast and other cancers.

To provide rapid and accurate detection of DNA markers in a straightforward, inexpensive and multiplex format, an alternative surface enhanced Raman scattering (SERS) based probe was designed and fabricated to covalently attach both DNA probing sequence and non-fluorescent Raman tags to the surface of gold nanoparticles (DNA-AuP-RTag). The intensity of Raman signal of the probes could be controlled through the surface coverage of the non-fluorescent Raman tags (RTags). Detection sensitivity of these probes could be optimized by fine-tuning the amount of DNA molecules and RTags on the probes. Long-term stability of the DNA-AuP-RTag probes was found to be good (over 3 months). Excellent multiplexing capability of the DNA-AuP-RTag scheme was demonstrated by simultaneous identification of up to eight probes in a mixture. Detection of hybridization of single-stranded DNA (ssDNA) to its complementary targets was successfully accomplished with a long-term goal to use non-fluorescent RTags in a Raman-based DNA microarray platform.

Nanotechnology is a growing science that has applications in various areas of medicine. The composition of nanocarriers for drug delivery is critical to guarantee high therapeutic performance when targeting specific host sites. Applications of nanotechnology are prevalent in the diagnosis and treatment of infectious and inflammatory diseases. This review summarizes recent advancements in the application of nanotechnology to the therapy of infectious and inflammatory diseases. The major focus is on the design and fabrication of various nanomaterials, characteristics and physicochemical properties of drug-loaded nanocarriers, and the use of these nanoscale drug delivery systems in treating infectious and inflammatory diseases, such as AIDS, hepatitis, tuberculosis, melanoma, and representative inflammatory diseases. Clinical trials and future perspective of the use of nanocarriers are also discussed in detail. We hope that such a review will be valuable to researchers who are exploring nanoscale drug delivery systems for the treatment of specific infectious and inflammatory diseases.

A fast and easy-to-operate Fourier Transform Infrared (FTIR) spectrometry-based approach was developed for microbial differentiation and quantiffcation in apple juice. Eight different microorganisms were eevaluated. Enterobacter cloacae, Salmonella typhimurium, Enterobacter aerogenes, Salmonella choleraesuis, Serratia marcescens, Pseudomonas vulgaris, Vibria cholerae, and Hafnia alvei. FTIR spectrascopy combined with chemometrics could differentiate the microorganisms studied at low concentration level of 10° colony-forming units (CFU)/mL in apple jeice. The chemometric models developed to count microorganisms in apple juice were valldated by an indepen dent test set consisting of 18 samples and correlated against plate counts satisfactorily up to a detection limit of 10 3 CFU/mL.

Multi-layered chalcogenide glass waveguide structures have been fabricated for evanescent wave sensing of bio-toxins and other sensor applications. Thin films of Ge containing chalcogenides have been deposited onto Si substrates, with a-GeSe2 as the lower cladding layer and a-GeSbSe as the core layer, to form the slab waveguide. The absence of a defined upper cladding layer enhances the leakage necessary to sense the target molecules. Modal refractive index is estimated from the m-lines. It is shown that photo-induced structural changes by 808 nm laser light in the core layer selectively enhance refractive index in the exposed regions, and thus provide a convenient method to form channel waveguides. A thin layer of Au has been deposited on top of the core layer for the attachment of linker molecules for biosensor application; ATR confirms this.

Routine identification of pathogenic microorganisms predominantly based on nutritional and biochemical tests is a time-consuming process. In this study, a method based on FTIR spectroscopy was developed to detect and identify the presence of five possible pathogenic bacteria in ten different microorganism mixtures with each cocktail containing up to three different species at a concentration of 109 CFU/mL. A mathematical approach based on factoring out the common features in the spectral fingerprints was developed and implemented in conjunction with discriminant analysis. FTIR spectra of the mixtures were directly obtained and analyzed using canonical variate analysis based on the discriminant model for the presence of particular species in the pathogenic bacteria mixtures. In nine out of ten mixtures, the predictions were 100% accurate; in one mixture, only one false negative was reported, with no false positives. Results suggest that FTIR spectroscopy combined with a suitable analytical procedure has excellent potential as a fast, powerful, and reliable alternative for identifying a specific foodborne pathogen in a complex and/or competing system.

A numerical model to simulate non-isothermal generalized Newtonian flow inside a deep-channel twin-screw cheese stretcher was developed. System variables (SME, MRT and TE) of the process were defined and mathematical models were developed to compute system variables from the flow field. The stretcher-cooker geometry and operating conditions strongly influence the system variables. Therefore, the stretcher-cooker geometry and operating conditions can be adjusted to control the process towards a desirable end. The technique developed in this study can help to improve the stretcher-cooker design and to optimize the pasta filata operation to obtain more desirable final product.

Pasta filata process during Mozzarella cheese manufacturing was studied. System variables (SME, specific mechanical energy; TE, exit temperature) were defined and their relationships to operating conditions were investigated. The compositional, rheological and functional properties of cheeses manufactured under different conditions were analyzed and relationships between system variables and cheese properties were established. The cheese moisture content decreased as SME increased. A quadratic relation was established between cheese moisture content and TE, FDM (fat-in-dry-matter) and SME and FDM and TE. These relationships suggested that optimization of the cheese yield is possible by adjusting the pasta filata process operating parameters. Evaluation of microstructural features of the cheese samples further supported these conclusions.

Numerical simulation was performed to analyze flow field and heat transfer developed inside a deep-channel, single-screw cheese stretcher channel. Modifications to the traditional flat-plate model of single-screw extruder geometry were applied to address flight effects and channel curvature effects. The finite difference and finite element methods were used to obtain numerical solutions to the flow and energy equations. Isothermal and non-isothermal conditions were considered for Newtonian flow and non-Newtonian (power-law and Bird–Carreau models) fluids. The model-predicted velocity distributions and screw characteristic curves were tested using the published experimental data. For Newtonian fluids at screw speeds above 150 rpm, our model predicted volumetric flow rate was within 0.5% of the experimental data compared to the typical 50% overprediction by the existing models. Our model performed much better than the published models for the case of the non-Newtonian fluids also. The simulation results show that in a deep-channel cheese stretcher, the flight effect is more important than the curvature effect in terms of the overall volumetric flow rate.

The worldwide decline and overexploitation of ocean fisheries stocks had provided incentive for rapid growth of aquaculture. The aquaculture industry has been recognized as the fastest-growing food production system globally, with a 10% increases in production per year, and is one of the most reliable and sustainable growth markets for manufactured feeds. Extrusion technology has been extensively used in the modern aquatic feed manufacturing, due to nutritional, physical properties improvements and cost effectiveness of feeds. Cost related to aquatic feed remains the biggest challenge, especially for small-scale producers. In this study a single screw extruders and three different scenarios (i.e. 0.2 tons/day, 2 tons/day, 20 tons/day) throughput were used to develop techno-economic models for small-scale producers of extruded aquatic feeds. The results show annualized capital costs decreased as production capacity increased. Thus, aquatic feed producers could use this tool to evaluate annual costs and benefits to determine processing economics.

Eight commercial foods representing a wide range of viscosities (i.e. honey, condensed milk, mayonnaise, tomato ketchup, cream cheese, yogurt, process and Mozzarella cheeses) were investigated. Their steady shear viscosity and dynamic complex viscosity were determined by rheological measurements at two temperatures using a Bohlin-CVO rheometer. Based on experimental data, shear rate dependence of steady flow apparent viscosity and frequency dependence of dynamic viscosity was established and compared. It was determined that for condensed milk, tomato ketchup and mayonnaise, a modified Cox-Merz relation could be established. For cream cheese, a generalized Cox-Merz relation was proposed; and for yogurt, a deviation from the Cox-Merz rule was found. For Mozzarella and process cheeses a sharp drop in steady shear viscosity was noticed between 1~10 s-1 shear rate range. The Cox-Merz rule was not applicable for these cheese samples.

Early detection of pathological changes and progression in glaucoma and other neuroretinal diseases remains a great challenge and is critical to reduce permanent structural and functional retina and optic nerve damage. Raman spectroscopy is a sensitive technique that provides rapid biochemical characterization of tissues in a nondestructive and noninvasive fashion. In this study, spectroscopic analysis was conducted on the retinal tissues of seven beagles with acute elevation of intraocular pressure (AEIOP), six beagles with compressive optic neuropathy (CON), and five healthy beagles. Spectroscopic markers were identified associated with the different neuropathic conditions. Furthermore, the Raman spectra were subjected to multivariate discriminate analysis to classify independent tissue samples into diseased/healthy categories. The multivariate discriminant model yielded an average optimal classification accuracy of 72.6% for AEIOP and 63.4% for CON with 20 principal components being used that accounted for 87% of the total variance in the data set. A strong correlation (R20.92) was observed between pattern electroretinography characteristics of AEIOP dogs and Raman separation distance that measures the separation of spectra of diseased tissues from normal tissues; however, the underlining mechanism of this correlation remains to be understood. Since AEIOP mimics the pathological symptoms of acute/early-stage glaucoma, it was demonstrated that Raman spectroscopic screening has the potential to become a powerful tool for the detection and characterization of early-stage disease.

For industrial and military applications, there is an increasing need for structural materials at elevated temperature beyond nickel-base superalloys. The Nb-Ti solid solution alloy possesses relatively high fracture toughness and good ductility. Some elements such as aluminum are added for better high temperature strength. After annealing, the strengthening phase precipitated in the grain boundary preferentially, and then grew into the grain. In order to control the size of the strengthening phase, the equations of dynamics of recrystallization and grain growth were obtained. After cold deformation, the uniform and tiny grain after annealing at 900–1020 °C can be obtained, the relation of volume fraction and annealing time can be described with Avrami equation. The recrystallization activation energy decreases as the increase of cold deformation, at the range of 249.2~208.9 kJ/mol. The influence of temperature and time on the grain growth of the alloy was also studied. Keywords: Nb-Ti-Al, dynamics of recrystallization, recrystallization activation energy, grain growth

Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cells and subsequent loss of visual function. Early detection of glaucoma is critical for the prevention of permanent structural damage and irreversible vision loss. Raman spectroscopy is a technique that provides rapid biochemical characterization of tissues in a nondestructive and noninvasive fashion. In this study, we explored the potential of using Raman spectroscopy for detection of glaucomatous changes in vitro. Raman spectroscopic imaging was conducted on retinal tissues of dogs with hereditary glaucoma and healthy control dogs. The Raman spectra were subjected to multivariate discriminant analysis with a support vector machine algorithm, and a classification model was developed to differentiate disease tissues versus healthy tissues. Spectroscopic analysis of 105 retinal ganglion cells (RGCs) from glaucomatous dogs and 267 RGCs from healthy dogs revealed spectroscopic markers that differentiated glaucomatous specimens from healthy controls. Furthermore, the multivariate discriminant model differentiated healthy samples and glaucomatous samples with good accuracy [healthy 89.5% and glaucomatous 97.6% for the same breed (Basset Hounds); and healthy 85.0% and glaucomatous 85.5% for different breeds (Beagles versus Basset Hounds)]. Raman spectroscopic screening can be used for in vitro detection of glaucomatous changes in retinal tissue with a high specificity.

Existing objective methods to predict sensory attributes of pork in general do not yield satisfactory correlation to panel evaluations, and their applications in meat industry are limited. In this study, a Raman spectroscopic method was developed to evaluate and predict tenderness, juiciness and chewiness of fresh, uncooked pork loins from 169 pigs. Partial Least Square Regression models were developed based on Raman spectroscopic characteristics of the pork loins to predict the values of the sensory attributes. Furthermore, binary barcodes were created based on spectroscopic characteristics of the pork loins, and subjected to multivariate statistical discriminant analysis (i.e., Support Vector Machine) to differentiate and classify pork loins into quality grades (“good” and “bad” in terms of tenderness and chewiness). Good agreement (> 83% correct predictions) with sensory panel results was obtained. The method developed in this report has the potential to become a rapid objective assay for tenderness and chewiness of pork products that may find practical applications in pork industry.

Anisotropic nanoparticles (i.e., silver nanocubes, gold nanorods) based SERS molecular probe were designed and fabricated for the rapid and specific detection of bacterial targets in a test-in-a-tube platform utilizing a novel dual-recognition mechanism. The probes were synthesized by covalently attaching Raman tags and bacteria-specific antibodies to the surface of silver nanocubes. Specific binding between the probes and bacterial targets ensured surface enhanced Raman spectroscopic (SERS) signatures of the targets to be observed alongside with the SERS signals of the Raman tags. The assessment through the dual signals (superimposed target and tag Raman signatures) established a specific recognition of the targets in a single step, no washing/separation steps were needed to separate target-bound probes from unbound ones, because unbound probes only yield tag signatures, and could easily be distinguished from the target-bound ones. The dual-recognition protocol implemented with a portable Raman spectrometer would become an easy-to-use, field-deployable spectroscopic sensor for onsite detection of pathogenic microorganisms.

Binding of Epidermal growth factor (EGF) to epidermal growth factor receptor (EGFR) in two types of cancer cells (HeLa; 5 x 10(4) EGFR/cell) and MDA-MB-468; 2 x 10(6) EGFR/cell) was studied using Total Internal Reflectance Fluorescence (TIRF) microscopy at single molecule precision. Mathematical modeling of the binding kinetics revealed that cells respond differently to the same concentration of EGF depending on the expression level of EGFR. Compared to Hela, MDA-MB-468 cells show; (a) higher number of pre-formed dimers, (b) improved EGF-EGFR interaction at lower ligand concentrations, and (c) shorter time-lapse between first and second EGF binding to the dimer. Treatment with a pharmacological inhibitor of EGFR, AG1478, produced strikingly different binding kinetics where the extent of pre-formed EGFR dimers increased substantially. Thus, single molecule approaches produce novel, quantitative information on signaling mechanisms of significant biological importance. Surface kinetics could also serve as surrogate markers to predict biological outcome of signaling pathways.

Nonfluorescent labels were used for an array-format multiplex detection of alternative splice junctions of breast cancer susceptibility gene 1 (BRCA1) by surface-enhanced Raman scattering (SERS). A four-plex detection scheme using nonfluorescent labels was demonstrated for DNA sequences specific to four BRCA1 alternative splice variants: Delta(11q) (the last 3309 nt deleted from exon 11), Delta(9, 10) (exon 9 and 10 deleted), Delta(5) (exon 5 deleted), and Delta(5q, 6) (the last 22 nt of exon 5 and the entire exon 6 is deleted). This is the first proof-of-concept study to apply SERS-based detection using nonfluorescent labels to investigate alternative gene splicing. Detection sensitivity of up to 1 fM was demonstrated for the Raman labels chosen to clearly discriminate the splice junctions via specific target identification. The proposed approach has the potential to become a highly sensitive and selective tool for comprehensive alternative splicing profiling of BRCA1 or other genes relevant to specific diseases.

A chemical procedure to replace the cetyltrimethylammonium bromide (CTAB) cap on gold nanorods (GNRs) fabricated through seed-mediated growth with organothiol compounds [3-animo-5-mercapto-1,2,4-triazole (AMTAZ) and 11-mercaptoundecaonic acid (MUDA)] was developed to reduce the cytotoxity of GNRs and facilitate further biofunctionalization. Compared to phosphatidylcholine (PC) modification, our procedure yields stable GNRs that are biocompatible and suitable for whole-cell studies. The PC-, AMTAZ-, and MUDA-activated GNRs all showed low cytotoxicity. By choosing different organothiols, net positive or negative charges could be created on the nanorod surface, for different applications. Gold nanorod molecular probes (GNrMPs) were fabricated by subsequent attachment of antibodies to the activated GNRs and were used to visualize and detect cell surface biomarkers in normal and transformed human breast epithelial cells, demonstrating the potential of developing novel biosensors using gold nanorods. The sensitivity of GNrMPs made from organothiol-activated GNRs is considerably higher than that of CTAB/PC-activated GNRs, demonstrating that the protocol reported here is favored in developing molecular probes using GNRs.