OBJECTIVETo evaluate the effect of chemical compounds extracted from Galla chinensis on enamel surface rehardening in vitro.

METHODSSixty bovine enamel blocks with early carious lesions were randomly divided into six groups: group1 treated NaF (positive control); group2 with GCE; group3 with GCE-B; group4 with GCE-B1; group5 with GCE-B2 and group6 with deionized water (negative control). The lesions were subjected to a pH-cycling regime for 12 days. Surface enamel microhardness was measured on the enamel blocks before and after demineralization. After pH-cycling, and the percentage of surface microhardness recovery (SMHR) was calculated.

RESULTSObvious increase of the surface hardness of the enamel was observed in all the treatments except GCE-B2 and deionized water (P < 0.05).

CONCLUSIONSThe present study demonstrates the potential of the three GCEs (GCE, GCE-B and GCE-B1) to effect net rehardening of artificial carious lesions under dynamic pH-cyclic conditions.

Animals ; Cattle ; Dental Caries ; drug therapy ; Dental Enamel ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Gallic Acid ; pharmacology ; In Vitro Techniques ; Tooth Remineralization

OBJECTIVETo assess the influence of mimic cardiac rate on hydrodynamics of different mechanical prosthetic cardiac valves.

METHODSUS-made CarboMedics bileaflet valve, China-made Jiuling bileaflet valve and C-L tilting disc valve were tested via a pulsatile flow simulator in the aortic position. Testing conditions were set at mimic cardiac rates of 55 bpm, 75 bpm, 100 bpm with a constant mimic cardiac output of 4 L/min. The mean pressure differences (deltaP), leakage volumes (L(E)V) and closing volumes (C(L)V) across each valve, and effective orifice areas (EOA) were analyzed.

RESULTSWithin physiological range, deltaP, L(E)V, and C(L)V decreased as mimic cardiac rate increased, with a large extent of variance. EOA increased along with an increase in mimic cardiac rate. It was a different response in terms of cardiac rate alteration for different types of mechanical prosthetic cardiac valves.

CONCLUSIONMimic cardiac rate change affects hydrodynamics of mechanical prosthetic cardiac valves. Within physiological range, the hydrodynamic of prosthetic bileaflet valve is better than that of tilting disc valve.

Biomechanical Phenomena ; Cardiac Output ; Cardiac Volume ; Heart Rate ; Heart Valve Prosthesis ; Hemodynamics ; In Vitro Techniques ; Prosthesis Design ; Pulsatile Flow

OBJECTIVETo evaluate the impacts of three different surgical approaches to urethral stricture on the erectile function of the patients.

METHODSThis study included 126 male patients with urethral stricture, 35 treated by substitution urethroplasty (group A), 52 by anastomotic urethroplasty (group B), and 39 by internal urethroplasty (group C). We evaluated the pre- and postoperative erectile function of the patients using IIEF-5 scores by telephone calls and interviews. We also monitored their nocturnal penile tumescence (NPT).

RESULTSThe IIEF-5 scores in groups A, B and C were 13.5 +/- 4.5, 11.1 +/- 4.8 and 14.5 +/- 4.41 respectively after surgery, all significantly decreased as compared with 17.1 +/- 2.6, 17.1 +/- 3.0 and 17.6 +/- 2.2 preoperatively (P < 0.05).

CONCLUSIONAll the three surgical approaches can reduce IIEF-5 scores in patients with urethral stricture, but anastomotic urethroplasty may induce a higher incidence of erectile dysfunction than the other two approaches.

Adult ; Aged ; Humans ; Intraoperative Period ; Male ; Middle Aged ; Penile Erection ; physiology ; Urethral Stricture ; surgery ; Urologic Surgical Procedures, Male ; methods ; Young Adult