ELECTROLESS PLATING OF COPPER ON POLYTETRAFLUOROETHYLENE FILMS MODIFIED BY SURFACE-INITIATED FREE RADICAL POLYMERIZATION OF 4-VINYLPYRIDINE

Surface modification of polytetrafluoroethylene (PTFE) films is done by exposing the films to a sodium naphthalenide (Na/naphtha) etchant, and esterification of 4,4'-azobis(4-cyanopentanoic acid) (ACP) with the hydroxyl groups covalently linked to the surface, followed by the surface-initiated free radical polymerization of 4-vinylpyridine (4 VP). The surface elemental composition and topography of the poly(4-vinylpyridine) (PVP) graft-functionalized PTFE surfaces (PTFE-g-PVP surfaces) were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance (ATR) FTIR spectroscopy, and atomic force microscopy (AFM). Water contact angles on the pristine PTFE surface and PTFE-g-PVP surfaces were measured. The PVP brushes on the PTFE surface with well-preserved pyridine groups were used not only as the chemisorption sites for the palladium complexes (without the need for prior sensitization by SnCl2) during the electroless plating of copper, but also as an adhesion promotion layer to enhance the adhesion of the electrolessly deposited copper to the PTFE surfaces. The T-peel adhesion strength of the electrolessly deposited copper to the PVP grafted PTFE (PTFE-g-PVP) surface could reach about 7.2 N/cm. This adhesion strength was much higher than that of the electrolessly deposited copper to the pristine or Na/naphtha-treated PTFE surface. Effects of the graft polymerization time and the activation time in the PdCl2 solution on the T-peel adhesion strength of the electrolessly deposited copper (from the Sn-free process) to the PTFE-g-PVP surface were determined.Polyterafluoroethylene, 4-vinylpyridine, adhesion, electroless plating

Interpretation of stripping at the bitumen–aggregate interface based on fluorescence tracing method

Asphalt pavement field performance largely depends on the stripping resistance at the bitumen–aggregate interface. However, the conventional stripping resistance evaluation method is unsuitable for direct and precise quantification of the retained bitumen film area on the aggregate surface that designates the stripping resistance between bitumen and aggregate phases under the action of vehicle wheels or moisture damage. This study proposed a novel fluorescence tracing method to quantify the exact area of aggregate coating loss in accordance with the bituminous-coated aggregate image processing technique. The fluorescence tracing image acquisition and analysis system for precisely calculating the bitumen stripping ratio of the bituminous-coated aggregate were established after the bitumen stripping test. The thresholding manner of the two-mode threshold algorithm was devised to segment the fluorescence-traced bituminous-coated aggregate image with high quality. The results demonstrated that the appropriate threshold value for segmenting the fluorescence-traced image mainly falls in the range of 60–70 for limestone, 90–110 for basalt, and 100–110 for both granites; the ability of aggregates based on their chemisorption capacity with bitumen is in the order of limestone, basalt, and granite; the fluorescence tracing method eliminated nearly 92.3% of the undesirable reflection on bitumen phase; the detected bitumen stripping ratio, raised by 65.87% on average and by 37.82% in the median value in contrast to the conventional visual detection manner. This research introduces a practical framework from an engineering perspective for visually quantifying the interpretation of the adhesive bond at the bitumen-aggregate interface with reasonable accuracy and confidence

Intravaginal lactic Acid bacteria modulated local and systemic immune responses and lowered the incidence of uterine infections in periparturient dairy cows.

The objective of this investigation was to evaluate whether intravaginal infusion of a lactic acid bacteria (LAB) cocktail around parturition could influence the immune response, incidence rate of uterine infections, and the overall health status of periparturient dairy cows. One hundred pregnant Holstein dairy cows were assigned to 1 of the 3 experimental groups as follows: 1) one dose of LAB on wk -2 and -1, and one dose of carrier (sterile skim milk) on wk +1 relative to the expected day of parturition (TRT1); 2) one dose of LAB on wk -2, -1, and +1 (TRT2), and 3) one dose of carrier on wk -2, -1, and +1 (CTR). The LAB were a lyophilized culture mixture composed of Lactobacillus sakei FUA3089, Pediococcus acidilactici FUA3138, and Pediococcus acidilactici FUA3140 with a cell count of 108-109 cfu/dose. Blood samples and vaginal mucus were collected once a week from wk -2 to +3 and analyzed for content of serum total immunoglobulin G (IgG), lipopolysaccharide-binding protein (LBP), serum amyloid A (SAA), haptoglobin (Hp), tumor necrosis factor (TNF), interleukin (IL)-1, IL-6, and vaginal mucus secretory IgA (sIgA). Clinical observations including rectal temperature, vaginal discharges, retained placenta, displaced abomasum, and laminitis were monitored from wk -2 to +8 relative to calving. Results showed that intravaginal LAB lowered the incidence of metritis and total uterine infections. Intravaginal LAB also were associated with lower concentrations of systemic LBP, an overall tendency for lower SAA, and greater vaginal mucus sIgA. No differences were observed for serum concentrations of Hp, TNF, IL-1, IL-6 and total IgG among the treatment groups. Administration with LAB had no effect on the incidence rates of other transition cow diseases. Overall intravaginal LAB lowered uterine infections and improved local and systemic immune responses in the treated transition dairy cows

GRAFTING POLY(N-ISOPROPYL ACRYLAMIDE) FROM POLY(VINYLIDENE FLUORIDE) MIROFILTRATION, MEMBRANES VIA DIRECT SURFACE-INITIATED, ATOM TRANSFER RADICAL POLYMERIZATION, AND TEMPERATURE SENSITIVITY

Well-defined poly(N-isopropyl acrylamide) (PNIPAAm) brushes on commercial hydrophobic poly(vinylidene fluoride) (PVDF) microfiltration membrane surfaces were prepared, via direct atom transfer radical polymerization (ATRP) with the secondary fluorinated site of PVDF as initiator and water as solvent at 80°C. The effect of solvents on the ATRP was studied in detail. The water as reaction solvent was in favor of surface-initiated ATRP of N-isopropyl acrylamide (NIPAAm) from secondary fluoride of PVDF membranes. The chemical composition and structure of the modified PVDF membrane surfaces were determined by attenuated total reflectance (ATR) Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The surface and cross-section morphology of membranes were studied by scanning electron microscopy (SEM). The pore sizes of the pristine PVDF membrane and the PNIPAAm-grafted PVDF membranes were measured using micro-image analysis and process software. The introduction of the well-defined PNIPAAm on the PVDF membrane gave rise to hydrophilicity. Water contact angles of PVDF membranes reduced after the surface grafting of PNIPAAm. Water fluxes and protein solution permeation experiments revealed that the PNIPAAm-grafted PVDF membranes exhibited temperature-responsive permeability. The unique microstructure of PNIPAAm brushes facilitated hydrophilicity below the lower critical solution temperature.Poly(vinylidene fluoride), membrane, ATRP, temperature sensitivity

Alterations of Innate Immunity Reactants in Transition Dairy Cows before Clinical Signs of Lameness

The objectives of this study were to evaluate metabolic and innate immunity alterations in the blood of transition dairy cows before, during, and after diagnosis of lameness during periparturient period. Blood samples were collected from the coccygeal vain once per week before morning feeding from 100 multiparous Holstein dairy cows during −8, −4, disease diagnosis, and +4 weeks (wks) relative to parturition. Six healthy cows (CON) and six cows that showed clinical signs of lameness were selected for intensive serum analyses. Concentrations of interleukin-1 (IL-1), interleukin-6 (IL-6), tumor necrosis factor (TNF), haptoglobin (Hp), serum amyloid A (SAA), lipopolysaccharide binding protein (LBP), lactate, non-esterified fatty acids (NEFA), and β-hydroxybutyrate (BHBA) were measured in serum by ELISA or colorimetric methods. Health status, DMI, rectal temperature, milk yield, and milk composition also were monitored for each cow during the whole experimental period. Results showed that cows affected by lameness had greater concentrations of lactate, IL-6, and SAA in the serum vs. CON cows. Concentrations of TNF tended to be greater in cows with lameness compared with CON. In addition, there was a health status (Hs) by time (week) interaction for IL-1, TNF, and Hp in lameness cows vs. CON ones. Enhanced serum concentrations of lactate, IL-6, and SAA at −8 and −4 wks before parturition were different in cows with lameness as compared with those of the CON group. The disease was also associated with lowered overall milk production and DMI as well as milk fat and fat-to-protein ratio. In conclusion, cows affected postpartum by lameness had alterations in several serum variables related to innate immunity and carbohydrate metabolism that give insights into the etiopathogenesis of the disease and might serve to monitor health status of transition dairy cows in the near future

DI/LC-MS/MS-Based Metabolic Profiling for Identification of Early Predictive Serum Biomarkers of Metritis in Transition Dairy Cows

The objectives of this study were to evaluate alterations of metabolites in the blood of dairy cows before, during, and after diagnosis of metritis and identify predictive serum metabolite biomarkers for metritis. DI/LC-MS/MS was used to analyze serum samples collected from both healthy and metritic cows during −8, −4, disease diagnosis, +4, and +8 wks relative to parturition. Results indicated that cows with metritis experienced altered concentrations of serum amino acids, glycerophospholipids, sphingolipids, acylcarnitines, and biogenic amines during the entire experimental period. Moreover, two sets of predictive biomarker models and one set of diagnostic biomarker models for metritis were developed, and all of them showed high sensitivity and specificity (e.g., high AUC values by the ROC curve evaluation), which indicate that serum metabolites identified have pretty accurate predictive, diagnostic, and prognostic abilities for metritis in transition dairy cows

Effect of treatment on the concentration of TNF in the serum.

<p>TNF: tumor necrosis factor-α; TRT = effect of treatment; Week = effect of week; TRT * Week = effect of the interaction between treatment and week. TRT1: □, two prepartum doses of LAB; TRT2: ○, two prepartum doses plus one postpartum dose of LAB; CTR: ♦, carrier only. LSM ± SEM, n = 10 in each group.</p

Effect of LAB on periparturient diseases of transition dairy cows.

<p>¹ TRT1: two prepartum doses of LAB.</p><p>² TRT2: two prepartum doses plus one postpartum dose of LAB.</p><p>³ CTR: carrier only.</p><p>⁴ Total uterine infections comprised metritis, clinical endometritis and pyometra.</p><p>⁵ Subclinical mastitis was declared when somatic cell count in milk was greater than 200,000/mL within five weeks after parturition.</p><p>^a-bNumbers within a row with different superscript letters are different at <i>P</i> < 0.05.</p><p>Effect of LAB on periparturient diseases of transition dairy cows.</p

Effect of treatment on the concentration of Hp in the serum.

<p>Hp: haptoglobin; TRT = effect of treatment; Week = effect of week; TRT * Week = effect of the interaction between treatment and week. TRT1: □, two prepartum doses of LAB; TRT2: ○, two prepartum doses plus one postpartum dose of LAB; CTR: ♦, carrier only. LSM ± SEM, n = 10 in each group.</p