Collective cell guidance by cooperative intercellular forces

Cells comprising a tissue migrate as part of a collective. How collective processes are coordinated over large multi-cellular assemblies has remained unclear, however, because mechanical stresses exerted at cell-cell junctions have not been accessible experimentally. We report here maps of these stresses within and between cells comprising a monolayer. Within the cell sheet there arise unanticipated fluctuations of mechanical stress that are severe, emerge spontaneously, and ripple across the monolayer. Within that stress landscape, local cellular migrations follow local orientations of maximal principal stress. Migrations of both endothelial and epithelial monolayers conform to this behaviour, as do breast cancer cell lines before but not after the epithelial-mesenchymal transition. Collective migration in these diverse systems is seen to be governed by a simple but unifying physiological principle: neighbouring cells join forces to transmit appreciable normal stress across the cell-cell junction, but migrate along orientations of minimal intercellular shear stress.     

Single-domain antibody bioconjugated near-IR quantum dots for targeted cellular imaging of pancreatic cancer

Successful targeted imaging of BxPC3 human pancreatic cancer cells is feasible with near-IR CdTeSe/CdS quantum dots (QDs) functionalized with single-domain antibody (sdAb) 2A3. For specific targeting, sdAbs are superior to conventional antibodies, especially in terms of stability, aggregation, and production cost. The bright CdTeSe/CdS QDs were synthesized to emit in the diagnostic window of 650-900 nm with a narrow emission band. 2A3 was derived from llama and is small in size of 13 kDa, but with fully-functional recognition to the target carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6), a possible biomarker as a therapeutic target of pancreatic cancer. For compelling imaging, optical may be the most sensible among the various imaging modalities, regarding the sensitivity and cost. This first report on sdAb-conjugated near-IR QDs with high signal to background sensitivity for targeted cellular imaging brings insights into the development of optical molecular imaging for early stage cancer diagnosis.     

Effect of heat treatments on the phytic acid content of maize products

Processing of maize (Zea mays L fresh and dry) for the production of various traditional products results in the loss of phytic acid. Fresh mature corn contains less phytic acid (1·71 g kg^?1) than dry corn (7·15–7.60 g kg^?1). The loss of phytic acid varies from 18·1 to 46·7% for fresh maize and from 11·5 to 52·6% for dry maize respectively among the heat treatments given. From a nutritional viewpoint, consumption of maize as chapati and after roasting in a sand bath or on charcoal will improve the availability of minerals.     

Influence of corn processing and frequency of feeding on cow performance

Twenty cows, including five fitted with rumen cannulae, were used to study the influence of corn processing and frequency of feeding on milk yield and ruminal fermentation characteristics. Cows were assigned to five treatments in a 5 x 5 Latin square experiment. Each period was 3 wk. Cows were fed 45% forage and 55% grain in a total mixed ration. Diets contained 35% corn either coarsely ground and fed once a day (1x), finely ground (FGC) fed 1x, steam-flaked (SFC) fed lx, FGC fed four times a day (4x), or SFC fed 4x. Processing of corn and frequency of feeding had no influence on dry matter intake. Digestibility of starch was increased 6 and 3 percentage units by feeding SFC corn compared with coarsely and finely ground corn, respectively. Cows fed SFC or FGC produced 4% more milk with lower fat content compared with coarsely ground corn. Increasing the feeding frequency did not improve milk fat content. The fat-corrected milk yield was not different among treatments. Feeding SFC resulted in a low acetate-to-propionate ratio in the rumen fluid than FGC. Cows fed SFC produced 45 and 115 g more milk protein per cow/d than cows fed FGC or coarse, respectively. With the value of increased milk protein observed in this study, it would be more economical to feed SFC or finely ground corn to dairy cows compared with coarse ground. The breakeven price of flaking corn in this study was $32 and $12/metric tonne compared with coarse and FGC, respectively. Based on a survey conducted by the authors, the price of flaking corn in the United States ranged between $7 to $22/metric tonne during year 2000.     

Comparison of mechanical and degradation properties of EG and EGDMA grafted gelatin films

Thin films of gelatin were prepared from gelatin granules in aqueous medium by casting and its mechanical properties like tensile strength (TS), tensile modulus (TM), and elongation at break (Eb %) were studied. Gelatin films were procured with two types of monomers such as 5% ethylene glycol (EG) and 5% ethylene glycol dimethacrylate (EGDMA) to increase the mechanical properties. Five percent of monomer solutions were prepared in MeOH along with 2% photoinitiator; Irgacure-651. Soaking time and UV radiation intensities were optimized with the extent of polymer loading (PL) and the mechanical properties of the cured films. Comparing the properties of EG and EGDMA treated gelatin film, EG showed the best performance. The EG-cured gelatin film with 5?min soaking time showed the highest tensile strength (58.6?MPa) and elongation at break (11.2%). The water uptake was determined for raw film (500.1%), EG grafted gelatin film (375.3%), and EGDMA grafted film (412.9%). The degradation properties in water and soil were determined for the raw and cured gelatin films. It was observed that the raw film degrades more than that of the treated films.     

Role of microporosity and surface functionality of activated carbon in methylene blue dye removal from water

Activated carbons have been prepared from jute stick by both chemical and physical activation methods using zinc chloride and steam, respectively. They were characterized by evaluating surface area, iodine number, pore size distribution, and concentration of surface functional groups. The chemically activated carbon largely featured micropore structure, while the physically activated carbon mainly featured macropore structure. The specific surface area of chemically and physically activated carbons was 2,325 and 723 m ² /g, while the iodine number was 2,105 and 815mg/g, respectively. The concentration of surface functional groups was determined by Boehm titration method, which suggested that different types of surface functional groups are randomly distributed on chemical activated carbons, while it is limited for physical activated carbon. The microporosity along with surface functional groups provided a unique property to chemically activated carbon to adsorb Methylene Blue dye to a large extent. The adsorption of dye was also affected by the adsorption parameters such as adsorption time, temperature and pH. Comparatively, higher temperature and pH significantly facilitated dye adsorption on chemically activated carbon.     

Physico-mechanical and degradation properties of biodegradable photografted coir fiber with acrylic monomers

Coir fibers were modified with 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA) and 2-hydroxyethyl acrylate (2-HEA) solutions under UV radiation. Monomer concentration and radiation dose were optimized in terms of grafting and tensile properties. It was found that 20 % HEMA at 20th UV pass, 30 % MMA at 15th UV pass and 25 % 2-HEA at 20th UV pass of radiation produced higher tensile properties over untreated sample. Urea of different concentrations (0.5–2 %) were incorporated into optimized solutions and 1 % urea showed the best properties of the fiber. Water uptake behavior and simulating weathering degradation properties were also performed.     

Systematics study through scanning electron microscopy; a tool for the authentication of herbal drug Mentha suaveolens Ehrh

In all over the world, herbal drugs are usually adulterated with similar species or varieties due to incorrect identification. Most of herbal products devoid purity and quality, therefore an attempt was carried out to identify plant species and authenticate its herbal drug products from Mentha suaveolens. Microscopy tools provide an excellent platform to identify plants at species level. In this study, microscopic and pharmacokinetic parameters of M. suaveolens were observed. Plant species were collected from high diverse areas of Northern Pakistan. Macro and micro‐morphology including palynology and anatomical features were analyzed to study M. suaveolens. Species characteristics were studied, while implementing microscopic techniques for the delimitation and identification of the species. Traditionally Mentha species are used to cure several diseases that is, digestive disorders, respiratory disorders. Micromorphology (stem, leaves, flowers structure, length etc.), palynology (shape, size of pollen etc.), and anatomical characters (types of stomata, epidermal cell shape, and trichomes) were studied. Micromorphology and anatomical characters were of great interest and significance to discuss the taxonomy of the species. Taxonomic characters were studied to characterize and authenticate the species. The aim of the present study is to observe in detail the taxonomic identification of the species in term of morphology, palynology, and foliar epidermal anatomy for the correct identification along with their medicinal uses in the area.     

Seed micromorphology and its taxonomic evidence in subfamily Alsinoideae (Caryophyllaceae)

Seed micromorphology of 13 species, belonging to four genera of subfamily Alsinoideae (Caryophyllaceae) were investigated with scanning electron microscopy (SEM), in order to assess their diagnostic significance at generic level and provide additional evidence on species delimitation, as well as correct identification and phylogenetic position. Genera and species of subfamily Alsinoideae exhibit great variation in ultrastructure and a high diversity of novel micromorphological characters were observed. Variation in seed shape, color, hilum, anticlinal wall, epidermal cell, cell surface, margins, and quantitative characters as length and width were studied in detail, compared, illustrated, and their taxonomic significant were discussed. Seed shapes of the species were classified as reniform, round, angular, subcircular, subreniform, and elliptical pyriform, with sub‐central, central, basal, and nearly basal hilum. Wavy, irregular, tetragonal, and elongated epidermal cells structure has been observed as an exomorphological character. The present findings show that the micromorphology of subfamily Alsinoideae provides taxonomic information and is helpful to distinguish different species. The results also explained that SEM morphology of seeds provide important data about affinity among taxa and give potential characters in delimitation of members of subfamily Alsinoideae at generic and species level. A principal component analysis allowed to highlight the most outsiders among seed micromorphology with a possible explanation. Taxonomic keys were developed based on micromorphological characters to delimit the species and useful for their quick identification within subfamily Alsinoideae.