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There is current interest in replacing petroleum-based additives in consumer paper products with abundantly available, renewable and sustainable biopolymers such as lignin-containing cellulose nanofibers (LCNFs) and cottonseed protein. This research characterized the performance of cottonseed protein isolate with/without LCNFs to increase the dry strength of filter paper. The application of 10% protein solution with 2% LCNFs as an additive improved the elongation at break, tensile strength and modulus of treated paper products compared to the improved performance of cottonseed protein alone. Improvements in tensile modulus and tensile strength were greatest for samples containing larger amounts of lignin and a greater degree of polymerization than for those with less lignin from the same biomass sources. [ABSTRACT FROM AUTHOR]

Background: Autohydrolysis is an extensively investigated pretreatment method due to its environmental friendliness. During autohydrolysis, most xylan from hemicellulose can be converted into xylooligosaccharides (XOS), and cellulose in the autohydrolyzed residues can be transformed into glucose after enzymatic hydrolysis. Both of these are value-added biochemicals in the biorefining process. In this work, paper mulberry (PM), which contains abundant protein, was utilized as a raw material to coproduce XOS and single-cell protein (SCP) through autohydrolysis and fermentation technologies. Results: The results showed that 8.3 g of XOS and 1.8 g of amino acids could be recovered in the autohydrolysate (based on 100 g raw material) after autohydrolysis (170 °C, 1 h). Moreover, 5.7 g of low-DP XOS along with 1.8 g of amino acids could be further obtained from the autohydrolysate after hydrolysis with endo-β-1-4-xylanase. In addition, 20.1 g of fermentable monosaccharides was recovered after hydrolyzing the autohydrolyzed PM with cellulase, which can be used to produce 4.8 g of SCP after fermentation with Candida utilis. Conclusion: As a valuable application of PM, a novel process is proposed to coproduce amino acid-rich XOS and SCP through autohydrolysis. The carbohydrate of PM is effectively converted to high value-added products. [ABSTRACT FROM AUTHOR]

ABSTRACT Composite materials made from fibrous support coated with agro-polymers are widely commercialized for different applications. But, their transfer properties have only been sparingly studied despite their importance in membrane technologies or food packaging. Furthermore, most of past studies on the topic have been focused on the impact of surface properties of the support on the final coated material structure and its properties; leaving unexplored the potential impact of the in-bulk structure of the support. This study demonstrated the influence of in-bulk structure and especially fibers refining degree of 4 kraft papers (SP28, 36, 60, and 80) on the structure, and surface and gas transfer properties of their respective wheat gluten (WG) coated papers (WGP28, 36, 60, and 80). Paper presenting a high fibers refining degree (SP28) exhibited very tight and narrow in bulk fibers network which prevented most of the WG-coated layer penetration, maintaining an important WG apparent layer on top of the paper and a small fibers/wheat gluten composite zone inside (WGP28). Such structure gave strong 'WG-like' properties to the final coated material with moderate oxygen permeation and high permselectivity (1.50 × 10−11 mol m−2 s−1 Pa−1 and 8.09, respectively for WGP28) whereas the highly impregnated structure of coated papers built on lowly refined papers (SP80, with wide and loose structure) gave coated materials presenting weak 'WG-like' properties, supposedly due to a thick composite zone presenting interfacial defects, with higher oxygen permeation and very limited permselectivity (11.90 × 10−11 mol m−2 s−1 Pa−1 and 1.06, respectively for WGP80). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2848-2858, 2013 [ABSTRACT FROM AUTHOR]

Improved understanding of cellulose swelling mechanism is beneficial for increasing the hydrolysis efficiency of cellulosic substrates. Here, we report a family 5 glycoside hydrolase ArCel5 isolated from the cellulose-gelatinizing fungus Arthrobotrys sp. CX1. ArCel5 exhibited low specific hydrolysis activity and high cellulose swelling capability, which suggested that this protein might function as an accessory protein. Homology modeling glycosylation detection revealed that ArCel5 is a multi-domain protein including a family 1 carbohydrate-binding module, a glycosylation linker, and a catalytic domain. The adsorption capacity, structural changes and hydrature index of filter paper treated by different ArCel5 mutants demonstrated that CBM1 and linker played an essential role in recognizing, binding and decrystallizing cellulosic substrates, which further encouraged the synergistic action between ArCel5 and cellulases. Notably, glycosylation modification further strengthened the function of the linker region. Overall, our study provides insight into the cellulose decrystallization mechanism by a novel accessory protein ArCel5 that will benefit future applications. [ABSTRACT FROM AUTHOR]

Exposure to natural rubber latex (NRL) can result in sensitivity to NRL protein with resulting allergic reactions. Low-cost, portable, simple, sensitive analytical tools for NRL protein measurements are needed for rapid and accurate assessments of allergenic risks at the point-of-care (POC) instead of using traditional methods that require large and expensive instruments, long-time analysis, and complex sample preparation steps. Here, an electrochemical paper-based analytical device (ePAD) is presented by combining sample preparation and electrochemical detection within a single device to offer a one-step NRL analysis. The lack of antibodies and/or enzymes against NRL makes POC analysis difficult. In this work, detection is based on electrochemical measurement of the remaining Cu after in situ protein complexation instead of more complex biological assays for the first time. Graphene screen-printed electrodes modified with 1,10-phenanthroline and Nafion were used in the ePAD to improve Cu signal 18-fold relative to unmodified carbon screen-printed electrodes. The optimum parameters including 1,10-phenanthroline concentration, reaction time between Cu and protein, and the starting Cu concentration were 5% w/v, 1 min, and 600 μg mL−1, respectively. In addition to short analysis time (4 min), the system selectivity indicated no other interfering species affecting protein detection. The proposed ePAD achieved an LOD of 3.0 mg dL−1 and a linear range of 10.0–200.0 mg dL−1. Finally, the proposed sensors were applied for NRL protein detection and the results were not significantly different from the traditional Lowry method at 95% confidence. [ABSTRACT FROM AUTHOR]

Paper has been proposed as an inexpensive and versatile carrier for microfluidics devices with abilities well beyond simple capillary action for pregnancy tests and the like. Unlike standard microfluidics devices, extracting a fluid from the paper is a challenge and a drawback to its broader use. Here, we extract fluid from narrow paper strips using surface acoustic wave (SAW) irradiation that subsequently atomizes the extracted fluid into a monodisperse aerosol for use in mass spectroscopy, medical diagnostics, and drug delivery applications. Two protein molecules, ovalbumin and bovine serum albumin (BSA), have been preserved in paper and then extracted using atomized mist through SAW excitation; protein electrophoresis shows there is less than 1% degradation of either protein molecule in this process. Finally, a solution of live yeast cells was infused into paper, which was subsequently dried for preservation then remoistened to extract the cells viaSAW atomization, yielding live cells at the completion of the process. The successful preservation and extraction of fluids, proteins and yeast cells significantly expands the usefulness of paper in microfluidics. [ABSTRACT FROM AUTHOR]

Background: It is important for industries to find green chemistries for manufacturing their products that have utility, are cost-effective and that protect the environment. The paper industry is no exception. Renewable resources derived from plant components could be an excellent substitute for the chemicals that are currently used as paper binders. Air laid pressed paper products that are typically used in wet wipes must be bound together so they can resist mechanical tearing during storage and use. The binders must be strong but cost-effective. Although chemical binders are approved by the Environmental Protection Agency, the public is demanding products with lower carbon footprints and that are derived from renewable sources. Results: In this project, carbohydrates, proteins and phenolic compounds were applied to air laid, pressed paper products in order to identify potential renewable green binders that are as strong as the current commercial binders, while being organic and renewable. Each potential green binder was applied to several filter paper strips and tested for strength in the direction perpendicular to the cellulose fibril orientation. Out of the twenty binders surveyed, soy protein, gelatin, zein protein, pectin and Salix lignin provided comparable strength results to a currently employed chemical binder. Conclusions: These organic and renewable binders can be purchased in large quantities at low cost, require minimal reaction time and do not form viscous solutions that would clog sprayers, characteristics that make them attractive to the non-woven paper industry. As with any new process, a large-scale trial must be conducted along with an economic analysis of the procedure. However, because multiple examples of "green" binders were found that showed strong cross-linking activity, a candidate for commercial application will likely be found. [ABSTRACT FROM AUTHOR]

A simple method is described for the patterned deposition of Teflon on paper to create an integrated platform for parallel organic synthesis and cell-based assays. Solvent-repelling barriers made of Teflon-impregnated paper confine organic solvents to specific zones of the patterned array and allow for 96 parallel flow-through syntheses on paper. The confinement and flow-through mixing significantly improves the peptide yield and simplifies the automation of this synthesis. The synthesis of 100 peptides ranging from 7 to 14 amino acids in length gave over 60 % purity for the majority of the peptides (>95 % yield per coupling/deprotection cycle). The resulting peptide arrays were used in cell-based screening to identify 14 potent bioactive peptides that support the adhesion or proliferation of breast cancer cells in a 3D environment. In the future, this technology could be used for the screening of more complex phenotypic responses, such as cell migration or differentiation. [ABSTRACT FROM AUTHOR]

There have been limited studies on the potential use of enzymes for enhancing the dewaterability of biosludge. The mechanisms for such enhancement have not been investigated despite the environmental advantages of using enzymes over synthetic polymers for biosludge conditioning. In order to find enzymes with this potential, a screening of commercially available enzymes was carried out using capillary suction time to assess biosludge dewaterability. The only enzyme that showed dewatering improvements in the screening tests was a lysozyme which reduced the capillary suction time by 36% and increased the cake solids content from 5.6 to 8.9 DS%. Lysozyme aided in the flocculation of particles reducing the polymer demand from 11% to 6%. Active and inactive lysozyme exhibited a similar ability for enhancing sludge dewatering, indicating that the conditioning mechanism of lysozyme is similar to that of a flocculant. [ABSTRACT FROM AUTHOR]

Paper-based analytical device (PAD) has received more and more attention in the field of point-of-care test (POCT) due to its low cost, portability and simple operation. Sensitivity and selectivity are two important aspects in clinical diagnostic analysis. However, low sensitivity of a PAD limits its wider application for POCT. Here we introduced a PAD that can clean and enrich the protein content from salty media with both electric field (E) and pH gradient (double E/pH gradients), with which 100-fold enrichment effect could be achieved within 70 s as demonstrated by fluorescein isothiocyanate labeled bovine serum albumin (FITC-BSA) from artificial urine media. With post staining of the protein stacking band with bromophenol blue (BPB), selective colorimetric detection of human serum albumin (HSA) was achieved simply with smartphone camera in the clinically significant range of 10–300 mg‧L−1 (R2 = 0.99) with a limit of detection (LOD) of 4.9 mg‧L−1. Detection of microalbuminuria (MAU) of diabetic patients was demonstrated with this method without difference (ɑ = 0.01) to that by the clinical method (immunoturbidimetry). This work demonstrated the potential of this PAD method in online sample pretreatment and detection of target component from complex physiological samples. Image 1 • Both electric field and pH gradient (E/pH double gradients) can be established and sustained on a paper fluidic channel. • Ampholytic content from salty sample media can be stacked/separated from other types of species. • Proteins from urine can be cumulatively stacked on the double gradient interface without intensive pre-treatment. • Sensitive and selective colorimetric detection of microalbuminuria (MAU) from clinical samples was successfully demonstrated. [ABSTRACT FROM AUTHOR]

This work reports on fully integrated "sample‐in‐signal‐out" microfluidic paper‐based analytical devices (μPADs) relying on bioluminescence resonance energy transfer (BRET) switches for analyte recognition and colorimetric signal generation. The devices use BRET‐based antibody sensing proteins integrated into vertically assembled layers of functionalized paper, and their design enables sample volume‐independent and fully reagent‐free operation, including on‐device blood plasma separation. User operation is limited to the application of a single drop (20–30 μL) of sample (serum, whole blood) and the acquisition of a photograph 20 min after sample introduction, with no requirement for precise pipetting, liquid handling, or analytical equipment except for a camera. Simultaneous detection of three different antibodies (anti‐HIV1, anti‐HA, and anti‐DEN1) in whole blood was achieved. Given its simplicity, this type of device is ideally suited for user‐friendly point‐of‐care testing in low‐resource environments. A single drop of blood on paper: Bioluminescent sensing proteins integrated into a multi‐layer paper‐based device allow the user‐friendly and simple quantification of monoclonal antibodies from a single drop of blood by simple color change monitoring. [ABSTRACT FROM AUTHOR]

This work presents an annotation tool that automatically locates mentions of particular amino‐acid residues in published papers and identifies the protein concerned. These matches can be provided in context or in a searchable format in order for researchers to better use the existing and future literature. [ABSTRACT FROM AUTHOR]

Proteinaceous toxins are harmful proteins derived from plants, bacteria, and other natural sources. They pose a risk to human health due to infection and also as possible biological warfare agents. Paper spray mass spectrometry (PS-MS) with wipe sampling was used to detect proteins from surfaces as a potential tool for identifying the presence of these toxins. Proteins ranging in mass between 12.4 and 66.5 kDa were tested, including a biological toxin simulant/vaccine for Staphylococcal enterotoxin B (SEBv). Various substrates were tested for these representative proteins, including a laboratory bench, a notebook cover, steel, glass, plant leaf and vinyl flooring. Carbon sputtered porous polyethylene (CSPP) was found to outperform typical chromatography paper used for paper spray, as well as carbon nanotube (CNT)-coated paper and polyethylene (PE), which have been previously shown to be well-suited for protein analysis. Low microgram quantities of the protein toxin simulant and other test proteins were successfully detected with good signal-to-noise from surfaces using a porous wipe. These applications demonstrate that PS-MS can potentially be used for rapid, sample preparation-free detection of proteins and biological warfare agents, which would be beneficial to first responders and warfighters. [ABSTRACT FROM AUTHOR]

Abstract A novel affinity paper-based electrochemical impedance device (PEID) was first fully developed for cardiovascular risk assessment. Herein, a simple folding PEID comprising a dual screen-printed electrode was fabricated for label-free electrochemical impedance detection. The results demonstrated in a step-wise manner that the phosphocholine-modified screen-printed carbon electrodes were highly responsive to the clinically required range of C-reactive protein (CRP) (0.005 – 500 mg L−1; r2 = 0.993) levels with a detection limit (3σ/slope) of 0.001 mg L−1. The optimal binding frequency of CRP–phosphocholine interaction was determined to be 100 Hz. These results implied that our proposed system could be used for simultaneously measuring the CRP levels using a single PEID platform in combination with the specific recognition elements. When assaying two levels of CRP, the overall assay reproducibility for each concentration, expressed as relative standard error of the mean (RSE%; n = 30), was 1.21%. The variation in the measurements between individual electrodes, expressed as the relative standard deviation (RSD), was 2.82%. Using 2 measurement sites per device, the proposed sensor provided excellent precision for the simultaneous detection of CRP. Moreover, the RSD for the CRP levels measured on ten independently fabricated paper-based sheets was 2.11%, thereby offering an acceptable fabrication reproducibility. The presented folding PEIDs were used forthe determination of CRP in patient-derived blood samples with minimised bias and excellent correlation with a standard method (n = 15; CUSUM linearity test, p > 0.10), thus permitting the potential application of PEID for assessing cardiovascular risk in individuals. Highlights • A PEID was developed for ultrasensitive label-free EIS detection of hs-CRP. • A simply folding step intended to create a small chamber for electrochemical assay. • A single specific-frequency determination facilitates fast impedance measurements. • An excellent agreement was demonstrated between the PEID and the standard method. [ABSTRACT FROM AUTHOR]

Replacing synthetic polymers with renewable alternatives is a critical challenge for the packaging industry. This research investigated the use of leaf‐based proteins as a sustainable co‐binder in the coating formulations for paper‐based packaging and other applications. Protein isolates from tobacco leaf and alfalfa concentrates were characterized using the Pierce protein assay, Kjeldahl nitrogen, and gel electrophoresis. The proteins were tested as co‐binders in a typical latex‐based paper coating formulation. The rheology and water retention properties of the wet coating and the surface, optical, structural, and strength properties of coated papers were measured. The coating performance was affected by the purity, solubility, and molecular weight of the tobacco protein and exhibited a shear‐thinning behavior with lower water retention than soy protein. Analysis by scanning electron microscopy and time of flight secondary ion mass spectroscopy on the dried coating layer containing tobacco protein showed enhanced porosity (advantageous for package glueability) relative to the control latex coating. The tobacco protein offers adequate coverage and coating pigment distribution, indicating that this protein can be a suitable option in coatings for packaging applications. [ABSTRACT FROM AUTHOR]

Products from rolling smoking tobacco, they are also “hand-rolled”, are currently a trending phenomenon in the development of the tobacco products market, both in the Russian Federation and abroad. In view of the fact that maximum allowable values for the content of nicotine, tar and carbon monoxide in smoke are set for cigarettes, manufacturers produce tobacco blendings for cigarettes with a high content of components such as reconstituted tobacco and extended stem, on the one hand, regulating toxicity, and on the other hand, reducing flavoring properties. This leads to the fact that modern cigarettes, in terms of taste and aroma of tobacco smoke, poorly meet consumer taste preferences. By creating products from rolling smoking tobacco, combining different types of tobacco, using paper for self-rolling paper of different composition and breathability, as well as changing the mass of tobacco and the diameter of the product, the consumer can create an ideal product that meets all his taste preferences. In connection with the growing popularity of hand-rolled cigarettes, the relevance of research on their qualitative characteristics is growing. This article discusses such qualitative characteristics as the chemical composition and technological properties of samples: raw tobacco; tobacco blendings with and without a vein; rolling smoking tobacco of various brands. The main purpose of the research is to study the influence of the design of the product (diameter, weight, air permeability of paper) on the tasting assessment. For each type of smoking tobacco, products (hand-rolled) of various weights and diameters have been made, using four types of paper, differing in composition and air permeability. The dependence of the tasting evaluation of products from rolling smoking tobacco on the air permeability of the paper and the design features of the products (fiber width, weight and diameter of the products) has been established.

Biosensors have emerged as a valuable tool with high specificity and sensitivity for fast and reliable detection of hazardous substances in drinking water. Numerous substances have been addressed using synthetic biology approaches. However, many proposed biosensors are based on living, genetically modified organisms and are therefore limited in shelf life, usability and biosafety. We addressed these issues by the construction of an extensible, cell-free biosensor. Storage is possible through freeze drying on paper. Following the addition of an aqueous sample, a highly efficient cell-free protein synthesis (CFPS) reaction is initiated. Specific allosteric transcription factors modulate the expression of ‘superfolder’ green fluorescent protein (sfGFP) depending on the presence of the substance of interest. The resulting fluorescence intensities are analyzed with a conventional smartphone accompanied by simple and cheap light filters. An ordinary differential equitation (ODE) model of the biosensors was developed, which enabled prediction and optimization of performance. With an optimized cell-free biosensor based on the Shigella flexneri MerR transcriptional activator, detection of 6 μg/L Hg(II) ions in water was achieved. Furthermore, a completely new biosensor for the detection of gamma-hydroxybutyrate (GHB), a substance used as date-rape drug, was established by employing the naturally occurring transcriptional repressor BlcR from Agrobacterium tumefaciens. [ABSTRACT FROM AUTHOR]

Microfluidic paper combines pump-free water transport at low cost with a high degree of sustainability, as well as good availability of the paper-forming cellulosic material, thus making it an attractive candidate for point-of-care (POC) analytics and diagnostics. Although a number of interesting demonstrators for such paper devices have been reported to date, a number of challenges still exist, which limit a successful transfer into marketable applications. A strong limitation in this respect is the (unspecific) adsorption of protein analytes to the paper fibers during the lateral flow assay. This interaction may significantly reduce the amount of analyte that reaches the detection zone of the microfluidic paper-based analytical device (µPAD), thereby reducing its overall sensitivity. Here, we introduce a novel approach on reducing the nonspecific adsorption of proteins to lab-made paper sheets for the use in µPADs. To this, cotton linter fibers in lab-formed additive-free paper sheets are modified with a surrounding thin hydrogel layer generated from photo-crosslinked, benzophenone functionalized copolymers based on poly-(oligo-ethylene glycol methacrylate) (POEGMA) and poly-dimethyl acrylamide (PDMAA). This, as we show in tests similar to lateral flow assays, significantly reduces unspecific binding of model proteins. Furthermore, by evaporating the transport fluid during the microfluidic run at the end of the paper strip through local heating, model proteins can almost quantitatively be accumulated in that zone. The possibility of complete, almost quantitative protein transport in a µPAD opens up new opportunities to significantly improve the signal-to-noise (S/N) ratio of paper-based lateral flow assays. [ABSTRACT FROM AUTHOR]

Suaeda maritima is a halophyte that has been evolutionary adapted to cope with saline and heavy metal conditions. The aim of the present study was to examine the biochemical response of Suaeda maritima against phytoextracting heavy metals and salts from paper mill effluent. Suaeda maritima seedlings have been grown for 120 days with an irrigation solution of 250 ml of 75% raw paper mill effluent after four drenching. Analysis of biochemical parameters revealed that maximum synthesis of chlorophyll, protein, phenol, proline and glycinebetaine may be involved in their ability to cope with heavy metal and salt stress. The present study confirms that the accumulation and increase of biochemical constituents can be considered as an efficient ROS scavenger and also maintain cellular homeostasis and metabolic functions in photosynthetically active leaves in Suaeda maritima, during phytoextraction studies. [ABSTRACT FROM AUTHOR]

Type 1 diabetes (T1D) is increasing in incidence and predictable with measurement of serum islet autoantibodies (iAb) years prior to clinical disease onset. Identifying iAb positive individuals reduces diabetic ketoacidosis and identifies individuals for T1D prevention trials. However, large scale screening for iAb remains challenging as assays have varying sensitivities and specificities, insulin autoantibodies remain difficult to measure and venipuncture is generally required to obtain serum. We developed an approach to reliably measure all four major iAb, including insulin autoantibodies, from dried blood spots (DBS) on filter-paper. By spiking iAb positive serum into iAb negative whole blood in a dose titration, we optimized the conditions for autoantibody elution from filter paper as measured by fluid phase radioimmunoassays. After assessing stability of measuring iAb from DBS over time, we then screened iAb from DBS and the corresponding serum in new-onset T1D (n = 52), and controls (n = 72) which included first-degree relatives of T1D patients. iAb measured from eluted DBS in new-onset T1D strongly correlated with serum measurements (R2 = 0.96 for mIAA, GADA = 0.94, IA-2A = 0.85, ZnT8A = 0.82, p<0.01 for each autoantibody). There were no false positives in control subjects, and 5/6 with previously unknown iAb positivity in sera were detected using DBS. With further validation, measuring iAb from DBS can be a reliable method to screen for T1D risk. [ABSTRACT FROM AUTHOR]

We studied the aging behaviour of gelatin used to size paper. Thus far, research on the aging of paper has largely ignored the sizing agent. Degradation of the protein was characterised and the impact of paper components, such as cellulose, and aluminium potassium sulphate was evaluated. Whatman No. 1 filter papers sized with two types of gelatins (A and B) were prepared as model samples. Commercially sized modern papers (Arches) were also studied in order to compare laboratory samples with real artist papers. Both types of papers were artificially aged (80 °C, 50% relative humidity for 35 and 94 days). Historic papers were included in the study in order to compare artificially aged with naturally aged gelatin. The aqueous extracts from the papers were characterised by aqueous size-exclusion chromatography (SEC) using four PL-Aquagel-OH columns and UV photodiode array detection at 220, 254 and 280 nm. Results showed that gelatin undergoes hydrolysis upon aging, type A gelatin showing a faster degradation rate than type B. The result was an increase in the lower-molar-mass fractions, under 50 000 g mol−1, and especially in a characteristic fraction with a peak molecular mass (Mp) of 14 000 g mol−1. A significant decrease in the extraction yields of α-, β- and γ-chains occurred after aging. This was attributed to crosslinking, leading to the formation of less-soluble polypeptides with very high molar mass (>800 000 g mol−1). Less than 10% alum had no impact on the degradation rate; higher alum contents accelerated hydrolysis reactions. [Copyright &y& Elsevier]

Abstract In this study, levels of inflammatory protein biomarkers in venous plasma, plasma derived from capillary blood from the earlobe, and capillary plasma stored as dried plasma spots (DPS) were compared. Samples from 12 male individuals were assessed with a panel of 92 inflammation-related proteins using multiplex proximity extension assay. Correlations between sample types varied greatly between analytes. A high correlation of ρ > 0.8 was observed between capillary plasma and DPS for 32 analytes. At this level of correlation, 13 analytes correlated between venous and capillary plasma and 5 analytes in the comparison of venous blood with DPS. Highlights • Measurement of an inflammation protein panel in three sample sources. • Earlobe plasma as a less invasive alternative sample source than venous plasma. • Protein measurement in capillary plasma stored as dried plasma spots (DPS). • Correlation value of ρ > 0.8 between capillary earlobe plasma and DPS for 32 analytes. • Correlation value of ρ > 0.8 between venous and capillary earlobe plasma for 13 analytes. [ABSTRACT FROM AUTHOR]

Abstract: Dried blood spot samples (DBSS) on filter paper offer several advantages compared to conventional serum/plasma samples: they do not require any phlebotomy or separation of blood by centrifugation; they are less invasive; they allow sample stability and shipment at room temperature; and they pose a negligible risk of infection with blood-borne viruses, such as HIV, HBV and HCV, to those who handle them. Therefore dried blood spot samples (DBSS) on filter paper can be a quick, convenient and inexpensive means of obtaining blood samples for biomarker discovery, disease screening, diagnosis and treatment monitoring in non-hospitalized, public health settings. In this study, we investigated for the first time the potential application of dried blood spot samples (DBSS) in protein expression profiling using antibody array technology. First, optimal conditions for array assay performance using dried blood spot samples (DBSS) was established, including sample elution buffer, elution time, elution temperature and assay blocking buffer. Second, we analyzed dried blood spot samples (DBSS) using three distinct antibody array platforms, including sandwich-based antibody arrays, quantitative antibody arrays and biotin-label-based antibody arrays. In comparison with paired serum samples, detection of circulating proteins in dried blood spot samples (DBSS) correlated well for both low- and high-abundance proteins on all three antibody array platforms. In conclusion, our study strongly indicates the novel application of multiplex antibody array platforms to analyze dried blood spot samples (DBSS) on filter paper represents a viable, cost-effective method for protein profiling, biomarker discovery and disease screening in a large, population-based survey. [Copyright &y& Elsevier]

The ratio of protein to creatinine (PCR) in urine is a measure of kidney health of a human body. We report the development of a point-of-care (POC) kidney function test (KFT) kit, which is composed of a paper-based PCR sensor, an opto-electrochemical measurement unit, a display, and a facility to transfer data to a smartphone. For the total protein sensor, the pieces of filter papers were coated with a mixture of alcoholic bromophenol blue and citric buffer leading to a chrome-yellow coloration. While for the creatinine sensor the papers were coated with alkaline picrate solution leading to a lemon-yellow coloration of the surface. Dispensing protein (creatinine) solution of known concentration on the respective sensors led to the conversion of chrome-yellow to bluish-green coloration (lemon-yellow to orange coloration) for the total protein (creatinine) sensor. The intensity of such colorations varied with the concentration of the analytes in the solutions. The variations in the intensities of colors with analyte concentration were quantified by integrating a light emitting diode (LED) at one side of each sensor and a light intensity sensor (LIS) on the other side. The intensity of the transmitted rays, passing through the sensors, was found to vary the electrical output of the LIS monotonically with the loading of the total protein or creatinine in the analyte. This helped in obtaining the calibration plots for the PCR sensors. Further, the sensors were employed for the on-spot detection of the unknown PCR in the real human urine samples. [ABSTRACT FROM AUTHOR]

Sensitivity is an important factor determining successful mass spectrometry (MS) analysis of metabolome, protein, drugs, and environmental samples. Currently, nanoelectrospray ionization (ESI) is widely used as a sensitive ionization method. However, application of nano-ESI is limited to polar molecules and there is no atmospheric pressure ionization technique developed that can be used for MS analysis of low- and nonpolar compounds with sensitivity that can match with nano-ESI. Herein, we propose paper spray chemical ionization (PSCI) as an ionization technique that can be used to analyze low- and nonpolar aromatic compounds with high sensitivity. PSCI is based on paper spray ionization utilizing corona discharge phenomenon. PSCI can sensitively and quantitatively detect down to picogram (or femtomole) levels of low- and nonpolar aromatic compounds. [ABSTRACT FROM AUTHOR]

Integration and storage of bioactive reagents is an important and challenging task in microfluidic paper-based analytical devices (μPADs). Here, we developed a convenient and universal method to store proteins and preserve their activities in μPADs by using aqueous two-phase systems (ATPs) evolved film. A polyethylene glycol (PEG)–dextran (DEX) double-layer film was formed through dehydration of ATPs. Functional biomolecules were stored in the bottom DEX layer on the basis of the biased partitioning and rehydrated conveniently by simple addition of buffer solution at usage. As a demonstration, enzyme immunoassay (EIA) of carcinoembryonic antigen was performed successfully on μPAD integrated with antibodies. Even after 104 days of storage at 4 °C and ambient conditions, the EIA signal just lost less than 10% and 30%, which meet the storage requirements of invitro diagnosis reagents. The ATPs evolved double-layer film has double functions of stabilization and insulation, and provide a high efficiency of biomolecule preservation, thereby promoting the applications of μPADs in POC diagnostic assay. We present a universal and high efficient biomolecules preservation technique using the PEG-DEX ATPs evolved double-layer film for paper based microdevice. [Display omitted] • Antibodies and enzyme were integrated on the paper based microdevice using the ATPs evolved double-layer film. • Signals of μPADs with integrated immuno-reagents were maintained more than 90% after 104 days of storage at 4 °C conditions. • This protein storing method possessed simple operation, high compatibility, and high efficiency in preserving biomolecules. [ABSTRACT FROM AUTHOR]

Many results have been obtained when studying scientific papers citations databases in a network perspective. Articles can be ranked according to their current in-degree and their future popularity or citation counts can even be predicted. The dynamical properties of such networks and the observation of the time evolution of their nodes started more recently. This work adopts an evolutionary perspective and proposes an original algorithm for the construction of genealogical trees of scientific papers on the basis of their citation count evolution in time. The fitness of a paper now amounts to its in-degree growing trend and a “dying” paper will suddenly see this trend declining in time. It will give birth and be taken over by some of its most prevalent citing “offspring”. Practically, this might be used to trace the successive published milestones of a research field. [ABSTRACT FROM AUTHOR]

Presents a study on the finding of abnormal protein components in a case of virus hepatitis and Laennec's cirrhosis. Importance of paper electrophoresis to the diagnosis of the disease; Role of paper electrophoresis and chemical fractionation in determining serum protein patterns; Discussion of the abnormal paper electrophoretic components.

Given their simplicity and functionality, paper-based microfluidic systems are considered to be ideal and promising bioassay platforms for use in less developed countries or in point-of-care services. Although a series of innovative techniques have recently been demonstrated for the fabrication of such platforms, development of simple, inexpensive and versatile new strategies are still needed in order to reach their full potential. In this communication, we describe a simple yet facile approach to fabricate paper-based sensor platforms with a desired design through a vapor-phase polymer deposition technique. We also show that the fabricated platforms could be readily employed for the detection of various biological target molecules including glucose, protein, ALP, ALT, and uric acid. The limit of detection for each target molecule was calculated to be 25 mg dL−1 for glucose, 1.04 g L−1 for protein, 7.81 unit per L for ALP, 1.6 nmol L−1 for ALT, and 0.13 mmol L−1 for uric acid. [ABSTRACT FROM AUTHOR]

Potato protein wastewater is produced by potato starch production. The wastewater has a large discharge, and is rich in organic matter such as protein and sugar. Most starch production enterprises directly discharge the wastewater to the sewage treatment plant, which not only increases the economic burden of enterprises, but also wastes resources in the wastewater. Therefore, the resource utilization of potato protein wastewater has practical significance to protect the environment, save resources and increase economic benefits of enterprises. The paper reviews the current situation of potato protein wastewater resource recycling and its application in animal production, in order to provide a reference for future research directions of potato protein wastewater. [ABSTRACT FROM AUTHOR]

We describe a sensitive immunological procedure for the detection of specific proteins in total cell extracts and for the comparison of antigenically related polypeptides. Proteins are fractionated in polyacrylamide gels and transferred electrophoretically to diazophenylthioether paper, to which they bind covalently. Specific proteins are identified by incubation with specific antibody and ⊃125 -labeled protein A from Staphylococcus aureus, followed by autoradiography. High-resolution separation of proteins prior to transfer is achieved by polyacrylamide gradient gel electrophoresis in the presence of sodium dodecyl sulfate or by nonequilibrium pH gradient electrophoresis, followed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Further information can be obtained by limited enzymatic proteolysis of the proteins in the gel following polyacryllamide gel electrophoresis in the presence of sodium dodecyl sulfate and analysis of the cleavage products by gel electrophoresis at right angles to the first gel. We show the application of this technique to the detection and comparison in extracts from infected cells of proteins related immunologically to the simian virus 40 capsid proteins VP1 and VP3. [ABSTRACT FROM AUTHOR]

Active cellulose-based packaging materials were prepared by binding lactoferrin to paper modified with anionic polyelectrolytes. About 63% of the protein added in the slurry was present in the finished paper, corresponding to about 0.28 mg protein per cm2 of the glassine paper produced. The efficacy of the activated materials was assessed by microbiological trials, employing targets bacteria considered as spoilage and/or pathogens in food products. Lactoferrin-activated paper evidenced its efficacy against growing cells of E. coli and L. innocua, with a maximum of 0.3 and 1.3 log cycles reduction of the final population, respectively. These results can be considered a promising starting point and will be the focus of further research, aimed at developing innovative cellulose-based active food packaging. [ABSTRACT FROM AUTHOR]

We present an origami paper-based electrophoretic device (oPAD-Ep) that achieves rapid (∼5 min) separation of fluorescent molecules and proteins. Due to the innovative design, the required driving voltage is just ∼10 V, which is more than 10 times lower than that used for conventional electrophoresis. The oPAD-Ep uses multiple, thin (180 μ/layer) folded paper layers as the supporting medium for electrophoresis. This approach significantly shortens the distance between the anode and cathode, and this, in turn, accounts for the high electric field (>1 kV/m) that can be achieved even with a low applied voltage. The multilayer design of the oPAD-Ep enables convenient sample introduction by use of a slip layer as well as easy product analysis and reclamation after electrophoresis by unfolding the origami paper and cutting out desired layers. We demonstrate the use of oPAD-Ep for simple separation of proteins in bovine serum, which illustrates its potential applications for point-of-care diagnostic testing. [ABSTRACT FROM AUTHOR]

Required metrological tools, such as higher order reference measurements procedures, pure substance and matrix certified reference materials, are established for small well defined molecules. Difficulties still remain in the provision of SI traceable standards in the area of larger biomolecules such as peptides/proteins. The provision of Primary Calibration Reference Services has been identified as a core technical competency for National Measurement Institutes (NMIs). A concept has been elaborated by the Focus Group I on peptide/protein purity for the strategic planning of ongoing Key Comparisons of the Protein Analysis Working Group (PAWG) within the Comité Consultatif pour la Quantité de Matière (CCQM). The assignment of the mass fraction content of high purity peptide/protein materials will be the subject of the CCQM-K115/P55.2 comparison series to directly support NMI services and certified reference materials currently being provided by NMIs. [ABSTRACT FROM AUTHOR]

The aim of this research is to use bibliometric analysis to investigate the status and patterns of the 100 most frequently cited publications regarding the cytotoxic T-lymphocyte-associated protein (CTLA-4) research for cancer. The articles published on the topic were retrieved from the core collection database of Web of Science and PubMed using the Medical Subject Heading (MeSH) of "CTLA-4" from 1986 to December 6, 2020. The selected articles were examined and the bibliometric data compiled based on the number of citations, the author's name, journal, publication year, institution, country, and co-occurrence keywords. 4,874 eligible papers were returned from the Web of Science Core Collection Database and PubMed. The citation frequency ranged from 2372 to 205, with a median of 460, and the top cited paper had 2372 citations. The journals with the most papers were Cell (n = 8, 3541 citations, Impact Factor (IF) = 41.577) and Journal of Experimental Medicine (n = 7, 2716 citations, IF = 10.790). Most of the published papers were from the United States of America (USA) (41.8%). A total of 485 institutes and 29 countries were involved in these 100 articles. There were 1192 authors and the author with the highest number of papers was the Nobel Prize winner, Professor James P. Allison (17 papers; 8700 citations). CTLA-4 blockade was the most frequent keyword (42.1%), followed by metastatic melanoma (4.26%). This work presents an important bibliographic source and can be saved as a reference for future medical health research on the function of CTLA-4 in cancer immunotherapy. [ABSTRACT FROM AUTHOR]