Covalent surface functionalization of nonwoven fabrics with controlled hydrophobicity,water absorption,and pH regulation properties

A modular method for functionalization of nonwoven fabrics was developed using a two-step process. In the first step, the fabrics were grafted with a linker molecule, 10-undecenoyl chloride, via esterification, followed by attachment of a functional material under UV irradiation. Perfluorodecanethiol and 3-mercaptopropionic acid (MPA) were connected to the linker-modified fabrics using thiol-ene click chemistry. Perfluorodecanethiol modified fabrics exhibited hydrophobicity with water contact angle of about 140° while MPA-modified fabrics were able to lower the pH of a solution by about 1.6. We additionally demonstrated the possibility to connect functional polymers to the linker-modified fabrics by radical graft polymerization of acrylic acid; this produced a thin layer of the polymer on the surface of the fabric. Fabrics modified with poly(acrylic acid) exhibited increased hydrophilicity with water contact angle of 0° for both cotton and viscose-polyester fabrics, while the water absorption capability for polypropylene fabrics increased from about 50 to 1200%.     

Effect of Initial Particle and Agglomerate Size on the Elastic Moduli of Porous Yttria (Y2O3)

The present study shows the effect of porosity on the dynamic elastic moduli of partially dense yttria (Y₂O₃). This article reveals that the sound velocities and the elastic moduli of the porous samples depend not only on density, but also upon the reciprocal of the initial particle and agglomerate size. These findings explain some of the variation in the elastic moduli found especially, but not only, for highly porous yttria.     

Total anomalous pulmonary venous connection in neonates and young infants: repair in the current era

Total anomalous pulmonary venous connection has been one of the more challenging congenital heart defects in newborns and young infants despite improvements in surgical technique, cardiac anesthesia, neonatal myocardial preservation, and postoperative care. Since 1981, 30 patients with total anomalous pulmonary venous connection have undergone primary total correction. Mean age at operation was 28 +/- 6 days and mean weight, 3.3 +/- 0.7 kg. Essential features of the surgical approach in these small patients included early surgical intervention, profound hypothermia with total circulatory arrest, cardioplegic myocardial preservation, and a wide posterior anastomosis. Operative mortality was 13% +/- 6%. All four deaths were in patients having emergency operation within 24 hours of the surgical consult and requiring ventilator support preoperatively. The mean follow-up is 47 +/- 7 months. There have been two late deaths, and the 7-year survival rate is 79% +/- 8%. There have been two reoperations, and 91% +/- 6% of the patients are reoperation free at 7 years. Only 1 of the 24 surviving patients is symptomatic. Growth in survivors is closely monitored. The height growth percentile is less than 5% in 15% +/- 8% of survivors and the weight growth percentile, less than 5% in 17 +/- 8%. During the past decade, with a consistent surgical approach to neonates and infants with total anomalous pulmonary venous connection, it has been possible to achieve low early mortality, low attrition, and excellent late results.     

Synthesis of Some Polymer Models of Potentially Biologically Active Compounds

2-(p-Styryl)-4-carboxyquinoline (vinyl cincophen), its 6-methyl and 6,7-benzo derivatives, p-formylstyryl thiosemicarbazone, and p-vinyl-DL-threo-β-phenylserine were synthesized and polymerized.     

Lupus anticoagulant. Significance in habitual first-trimester abortion

Therapy with steroids and aspirin has been reported to benefit pregnancies in patients with lupus anticoagulant (LA). In this study, habitual first-trimester aborters with LA using steroids and aspirin were compared to a control group of untreated habitual aborters without LA. In habitual aborters with LA, 12 of 24 (50%) pregnancies reached the second trimester as compared to 8 of 22 pregnancies (36%) in the control group. Since the treated group did no better than the control group, LA probably is not a cause of first-trimester abortion. However, once the second trimester is reached, a 50% incidence of growth retardation was found, and 42% of fetuses died in the second or third trimester in treated LA patients. Treatment with steroids and anti-platelet aggregating agents may be necessary despite the attendant risks to prevent those sequelae in the second and third trimesters. There was a 29% live birth rate in treated LA patients; the rate was 36% in control patients. However, this rate was produced only by early intervention, which was unnecessary in the control patients.     

A population-based prospective evaluation of risk of sudden cardiac death after operation for common congenital heart defects

1. Ischaemic cardiac preconditioning represents an important cardioprotective mechanism which limits myocardial ischaemic damage. The aim of this investigation was to assess the impact of dichloroacetate (DCA), a pyruvate dehydrogenase complex activator, on preconditioning. 2. Rat isolated hearts were perfused by use of the Langendorff technique, and were subjected to either preconditioning (3 x 4 or 3 x 6 min ischaemia) or continuous perfusion, followed by 30 min global ischaemia and 60 min reperfusion. DCA (3 mM) was either given throughout the protocol (pretreatment), during reperfusion only (post-treatment), or not at all. Throughout reperfusion mechanical performance was assessed as the rate-pressure product (RPP: left ventricular developed pressure x heart rate). 3. In non-preconditioned control hearts, mechanical performance was substantially (P < 0.001) depressed on reperfusion (the RPP after 60 min of reperfusion (RPP(t=60)) was 4,246+/-974 mmHg beats min(-1) compared to baseline value of 21,297+/-1,728 mmHg beats min(-1)). Preconditioning with either 3 x 4 min or 3 x 6 min cycles caused significant protection, as shown by enhanced recovery (RPP(t=60) = 7,818+/-1,138, P < 0.05, and 11,123+/-587 mmHg beats min(-1), P < 0.001, respectively). 4. Addition of DCA (3 mM) to hearts under baseline conditions significantly (P < 0.001) enhanced systolic function with an increased left ventricular developed pressure of 108+/-5 mmHg compared to 88.3+/-3.0 mmHg in the controls. 5. Pretreatment with 3 mM DCA had no effect on recovery of mechanical performance in the non-preconditioned hearts (RPP(t=60) = 3,640+/-1,235 mmHg beats min(-1)) while the beneficial effects of preconditioning were reduced in the preconditioned hearts (3 x 4 min: RPP(t=60) = 2,919+/-1,060 mmHg beats min(-1); 3 x 6 min: RPP(t=60) = 8,032+/-1,367 mmHg beats min(-1)). Therefore, DCA had increased the threshold for preconditioning. 6. By contrast, post-treatment of hearts with 3 mM DCA substantially improved recovery on reperfusion in all groups (RPP(t=60) = 5,827+/-1,328 (non-preconditioned), 14,022+/-3,743 (3 x 4 min; P < 0.01) and 23,219+/-1,374 (3 x 6 min; P < 0.001) mmHg beats min(-1)). 7. The results of the present investigation clearly show that pretreatment with DCA enhances baseline cardiac mechanical performance but increases the threshold for cardiac preconditioning. However, post-treatment with DCA substantially augments the beneficial effects of preconditioning.     

Interferometric technique for measuring dispersion of high ordermodes in optical fibres

An interferometric technique for chromatic dispersion measurement of higher modes in short lengths of high order mode fibres is presented. The dispersion is measured using the wavelength dependence of the interference signal between the basic mode and the high order mode. Neither mode transformers nor RF circuitry are required     

Percutaneous cardiac catheterization and atrial balloon septostomy in pediatrics

Between November, 1971, and July, 1975, 688 patients ranging in age from six hours to 21 years have undergone percutaneous transfemoral venous and/or arterial catheterization at the University of Oregon Health Sciences Center. This represents 93% of all venous catheterizations of the right side of the heart and 97% of all arterial catheterizations of the left side of the heart in the pediatric age range. One hundred and ninety-five patients (29% of the group) weighed 5 kg or less and 133 (20% of the group) were neonates. There were virtually no complications following the venous studies. The complication rate following percutaneous arterial studies is lower than is the reported experience with cut-down arteriotomies. Long-term survival following percutaneous atrial balloon septostomy in D-transposition of the great arteries was comparable to that following cut-down balloon septostomy. The ease of accomplishment, significantly lower complication rate, and successful accomplishment of atrial balloon septostomy prompt us to advocate that the percutaneous technique of cardiac catheterization be extended to include the neonate and young infant who weighsless than 5 kg.     

Geometry-Directed Generation and Synthetic Application of α-Lithio Oxime Ethers

Several mono- and di-O-alkyloximes have been regioselectively transformed to the syn α-lithio derivatives by treatment with n-butyllithium. The control of oxime ether geometry served to control regioselectivity in α-lithiation and subsequent carbon-carbon (alkylation, oxidative coupling) and carbon-halogen bond formation reactions. The geometry-directed α-lithiation-dimerization sequence was used for the synthesis of large ring compounds.