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A novel surface modification technique was developed to provide a copper nickel alloy (M) surface with bactericidal and anticorrosion properties for inhibiting biocorrosion. 4-(chloromethyl)-phenyl tricholorosilane (CTS) was first coupled to the hydroxylated alloy surface to form a compact silane layer, as well as to confer the surface with chloromethyl functional groups. The latter allowed the coupling of 4-vinylpyridine (4VP) to generate the M-CTS-4VP surface with biocidal functionality. Subsequent surface graft polymerization of 4VP, in the presence of benzoyl peroxide (BPO) initiator, from the M-CTS-4VP surface produced the poly(4-vinylpyridine) (P(4VP)) grafted surface, or the M-CTS-P(4VP) surface. The pyridine nitrogen moieties on the M-CTS-P(4VP) surface were quaternized with hexylbromide to produce a high concentration of quaternary ammonium groups. Each surface functionalization step was ascertained by X-ray photoelectron spectroscopy (XPS) and static water contact angle measurements. The alloy with surface-quaternized pyridinium cation groups (N+) exhibited good bactericidal efficiency in a Desulfovibrio desulfuricans-inoculated seawater-based modified Barr's medium, as indicated by viable cell counts and fluorescence microscopy (FM) images of the surface. The anticorrosion capability of the organic layers was verified by the polarization curve and electrochemical impedance spectroscopy (EIS) measurements. In comparison, the pristine (surface hydroxylated) Cu-Ni alloy was found to be readily susceptible to biocorrosion under the same environment.

Stimuli-responsive polymers are of crucial importance in the design of smart biomaterials. The thermo-responsive triblock copolymers of polycaprolactone (PCL) and poly( N-isopropylacrylamide) (P(NIPAAm)), or P(NIPAAm)- b-PCL- b- P(NIPAAm) copolymers, were synthesized in this work via atom transfer radical polymerization (ATRP). The P(NIPAAm)- b-PCL- b-P(NIPAAm) copolymers were cast by phase inversion in water into porous membranes with well-defined and uniformly distributed pores. The P(NIPAAm) content in the P(NIPAAm)- b-PCL- b- P(NIPAAm) copolymers and the temperature of the aqueous medium for phase inversion could be used to control the pore size and porosity of the membranes. The thermo-responsive characteristics of the membranes were illustrated in the controlled water uptake and temperature-dependent glucose transport through the membranes. These temperature-sensitive membranes with controllable morphology have potential applications in biomedical engineering, drug delivery, and tissue engineering.

Microbiologically influenced corrosion (MIC) of stainless steel 304 by a marine aerobic Pseudomonas bacterium in a seawater-based medium was investigated by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM was used to observe in situ the proliferation of a sessile Pseudomonas cell by binary fission. The development of a biofilm on the coupon surface and the extent of corrosion damage beneath the biofilm after various exposure times were also characterized by AFM. Results showed that the biofilm formed on the coupon surface increased in thickness and heterogeneity with time, and thus resulting in the occurrence of extensive micro-pitting corrosion; whilst the depth of pits increased linearly with time. The XPS results confirmed that the colonization of Pseudomonas bacteria on the coupon surface induced subtle changes in the alloy elemental composition in the outermost layer of surface films. The most significant feature resulting from microbial colonization on the coupon surface was the depletion of iron (Fe) and the enrichment of chromium (Cr) content as compared to a control coupon exposed to the sterile medium, and the enrichment of Cr increased with time. These compositional changes in the main alloying elements may be correlated with the occurrence of extensive micropitting corrosion on the surface.

Objective: To investigate the difference of apoptosis and expression of apoptotic related genes p53 bcl-2 C-myc in the development of oral lichen planus(OLP)., Methods: Apoptotic cells were detected by TUNEL and immunohistochemical method was used to study P53 bcl-2 C-myc expression in 45 samples with OLP(23 cases of erosive OLP group and 22 cases of non erosive OLP group)., Results: Apoptosis occurred in 100% of the cases and apoptotic index(AI) was 24.3%+/-12.0% (1.9%-50.5%). AI of erosive OLP group was 19.0%+/-10.4% (1.9%-50.5%), and AI of non erosive OLP was 29.4%+/-11.2% (10.4%-49.3%). The obvious differences existed between erosive group and non erosive group (P<0.05). The expression of p53 bcl-2 C-myc positive rates were 31.1% 35.5% 33.3% respectively. The p53 bcl-2 C-myc positive rates in erosive OLP group were 39.1% 52.2% 43.2%and that with non-erosive OLP group were 22.7% 18.2% 22.7% respectively. There was only statistically significance between erosive group and non-erosive group (P<0.05) in expression of bcl-2., Conclusion: Apoptosis and apoptotic related genes p53 bcl-2 C-myc participate in clinical development of OLP. The changes of AI are related to the chronic inflammation of lesion with OLP. We should attach importance to over expression of bcl-2 in erosive OLP.

Aim: To optimize the design of antisense drug targeting protein kinase C-alpha (PKC-alpha) mRNA and obtain better antisense drugs than ISIS3521 that is undergoing clinical trials., Methods: RNAstructure (version 3.21, 1999) was utilized to predict the optimal and suboptimal secondary structures of human PKC alpha mRNA (GenBank, X52479), and 29 antisense phosphorothioate oligodeoxynucleotides (S-ODN) targeting the secondary structural elements, 3 partly matched S-ODN and 1 scrambled 3521 were designed. ISIS3521 was set as positive control. Mean (n = 3-5) 50% inhibitory effects on proliferation of A549 cells (IC50) of S-ODN were evaluated. Free energies (delta G degree 37) relating to the target secondary structural elements were calculated according to the nearest neighbor model. The quantitative structure-activity relationship (QSAR) analysis through multiple regression was obtained by SPSS., Results: Three S-ODN; (5'-AGCCCA-GCCGCTTGGCTGGG-3', 5'-AGGAGTGCAGCTGC-GTCAAG-3', 5'-TCAGAGGG-ACTGATGACTTT-3') had lower IC50[(48 +/- 7), (50 +/- 4), (64 +/- 2.7) nmol.L-1, respectively] than that of ISIS3521 [(81 +/- 25) nmol.L-1]. The number of bases comprising the target secondary structural element bulge loop, internal loop, and knot, the free energy of S-ODN (delta G degree 37S), and reaction (delta G degree 37R) were important parameters in QSAR equation. In the multiple regression, R was 0.68, P = 0.0193. Not tally with the equation, two S-ODN (5'-TCAAATGGAGG-CTGCCCGGC-3', 5'-AAAACGTCAGCCATGGTCCC-3') with favorable target structures and delta G degree 37 did not behave good activities., Conclusion: Computer aided design was helpful to obtain S-ODN with better in vitro effect than current positive drug. The degree of instability of secondary structural elements and delta G degree 37 were important factors for drug activity. Other important factors needed for further investigation.

Ninety-five patients with perforation, hemorrhage or stenosis due to duodenal ulcer were treated by extended parietal cell vagotomy. Postoperative follow-up ranged from 3.5 to 10 years (mean 6 years) in 88 patients (92%) with acute perforation (60), hemorrhage (8) and stenosis (20). There was no operative mortality. Ulcer recurrence was 2.3%. Only one patient (5%) had restenosis and required reoperation. There was no recurrent hemorrhage and there were few long-term complications. According to the Visick classification, 67 patients (76%) belonged to grade I, 13 (14.7%) grade II, 4 (4.5%) grade III, and 4 (4.5%) grade IV. Extended parietal cell vagotomy proved to be safe with excellent results, low ulcer recurrence and few complications. Moreover, recurrent ulcers healed rapidly following medical therapy. The authors believe that extended parietal cell vagotomy should be the treatment of choice for acute perforation, hemorrhage or stenosis due to duodenal ulcer.