The sequential treatment of dewaxed sugarcane bagasse with H(2)O and 1 and 3% NaOH at a solid to liquid ratio of 1:25 (g mL(-1)) at 50 degrees C for 3 h yielded 74.9% of the original hemicelluloses. Each of the hemicellulosic fractions was successively subfractionated by graded precipitation at ethanol concentrations of 15, 30, and 60% (v/v). Chemical composition, physicochemical properties, and structures of eight precipitated hemicellulosic fractions were elucidated by a combination of sugar analysis, nitrobenzene oxidation of bound lignin, molecular determination, Fourier transform infrared (FT-IR), (1)H and (13)C nuclear magnetic spectroscopies, and thermal analysis. The results showed that the sequential treatments and graded precipitations were very effective on the fractionation of hemicelluloses from bagasse. Comparison of these hemicelluloses indicated that the smaller sized and more branched hemicelluloses were extracted by the hot water treatment; they are rich in glucose, probably originating from alpha-glucan and pectic polysaccharides. The larger molecular size and more linear hemicelluloses were dissolved by the alkali treatment; they are rich in xylose, principally resulting from l-arabino-(4-O-methylglucurono)-d-xylans. In addition, noticeable differences in the chemical composition and molecular weights were observed among the graded hemicellulosic subfractions from the water-soluble and alkali-soluble hemicelluloses. The Ara/Xyl ratio increased with the increment of ethanol concentration from 15 to 60%, and the arabinoxylans with higher Ara/Xyl ratios had higher molecular weights. There were no significant differences in the structural features of the precipitated hemicellulosic subfractions, which are mainly constituted of l-arabino-(4-O-methyl-d-glucurono)xylan, whereas the difference may occur in the distribution of branches along the xylan backbone.

Assembling multifunctional thin devices onto arbitrary curvilinear surfaces allows widespread and innovative applications in artificial intelligence and advanced healthcare industries.

MS. Speckletracking echocardiography correctly identifies segmental left ventricular dysfunction induced by scarring in a rat model of myocardial infarction. Am J Physiol Heart Circ Physiol 292: H2809 -H2816, 2007. First published February 2, 2007; doi:10.1152/ajpheart.01176.2006.-Speckle-tracking echocardiography (STE) uses a two-dimensional echocardiographic image to estimate two orthogonal strain components. The aim of this study was to assess sensitivity of circumferential (Scirc) and radial (Srad) strains to infarct-induced left ventricular (LV) remodeling and scarring of the LV in a rat. To assess the relationship among Scirc, Srad, and scar size, two-dimensional echocardiographic LV short-axis images (12 MHz transducer, Vivid 7 echo machine) were collected in 34 Lewis rats 4 to 10 wk after ligation of the left anterior descending artery. Percent segmental fibrosis was assessed from histological LV cross sections stained by Masson trichrome. Ten normal rats served as echocardiographic controls. Scirc and Srad were assessed by STE. Histological data showed consistent scarring of anterior and lateral segments with variable extension to posterior and inferior segments. Both Scirc and Srad significantly decreased after myocardial infarction (P Ͻ 0.0001 for both). As anticipated, Scirc and Srad were lowest in the infarcted segments. Multiple linear regression showed that segmental S circ were similarly dependent on segmental fibrosis and end-systolic diameter (P Ͻ 0.0001 for both), whereas segmental S rad measurements were more dependent on end-systolic diameter (P Ͻ 0.0001) than on percent fibrosis (P Ͻ 0.002). STE correctly identifies segmental LV dysfunction induced by scarring that follows myocardial infarction in rats.infarction; collagen; contractility RECENT ADVANCES in noninvasive imaging of the left ventricle (LV) have enabled the quantification of regional function with an accuracy and simplicity that were not available previously. One of these newer methods is speckle-tracking echocardiography (STE). STE uses a standard two-dimensional echocardiographic image to estimate two orthogonal strain components (25). This method has a potential to revolutionize noninvasive assessment of regional ventricular (and possibly atrial) function (25). Although similar data can be extracted by Doppler tissue echocardiography (2), the value of this method is the freedom of the insonation angle and an ability to adopt a local coordinate system for strain measurement.Although STE was recently validated in a variety of settings (1,5,10,17, 22), the relationship of strain to underlying muscle histology is uncertain. It is unknown as to what measure a decreased strain represents muscle loss, presence of ischemia, or a simple contractility decrease. Finally, the applicability of this method to small-animal echocardiography is unknown.The aim of this study was to assess sensitivity of circumferential (S circ ) and radial (S rad ) midwall strain components to LV remodeling and scarring induced by the myocardial infarction (MI...

Hyper-stretchable self-powered sensors with high sensitivity and excellent stability using low-cost, printable, organic nanomaterials are attractive for immense applications. Here we present self-similar piezoelectric nano/ microfibers for a hyper-stretchable self-powered sensor that demonstrates high stretchability (> 300%), low detection limit (0.2 mg), and excellent durability (> 1400 times at strain 150%). A proposed helix electrohydrodynamic printing technique (HE-Printing) in combination with in-surface self-organized buckling is used to fabricate aligned self-similar poly[vinylidene fluoride] (PVDF) nano/microfibers with in situ mechanical stretch and electrical poling to produce excellent piezoelectric properties. The hyper-stretchable self-powered sensors have shown repeatable and consistent electrical outputs with detection limit an order of magnitude smaller than the other stretchable sensors. Additionally, such sensors can simultaneously measure the own status and the extra multiply physical quantities, such as lateral pressure, impulse rate and applied strain. The high sensitivity can be further utilized to remotely detect human motion in addition to sensing a piece of paper with 1 mm × 1 mm. Further the fiber-based sensors can avoid the catastrophic collapse or wrinkling of serpentine film-based structure during stretching.

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