Strength of a 'no-bottle' adhesive system bonded to enamel and dentine

Existing bonding systems permit effective bonding to enamel or dentine. Bonding to dentine is mainly achieved through the hybridization of dentine with resin. However, despite their success, the 'three-bottle' systems do have drawbacks--the large number of steps involved may be confusing and prone to errors of application, as well as being time consuming. Recently developed systems have significantly reduced the number of steps and the total treatment time, but deliver a reliable outcome.     

A study of the thermal degradation of poly(mono-n-alkyl itaconates)

The thermal degradation of the first six members of poly(mono-n-alkyl itaconates) by thermogravimetry (TG), differential scanning calorimetry (DSC), Fourier Transform infrared (FTIR) and FTIR evolved gas analysis (FTIR-EGA) was studied. The degradation mechanism involves cyclic anhydride formation followed by crosslinking due to the linear anhydride formation. In both processes water and/or alcohol evolution was detected. Also, decarboxylation processes take place on all polymers at high temperatures ( > 180°C). A mechanism of the degradation process is proposed.     

Epididymal sparing bilateral simple orchiectomy with epididymoplasty: preservation of esthetics and body image

PURPOSE: We report the surgical technique and results of epididymal sparing bilateral simple orchiectomy as an esthetic alternative to standard bilateral simple orchiectomy and luteinizing hormone releasing hormone (LH-RH) agonist injection therapy in patients with prostate cancer. MATERIALS AND METHODS: The study included 91 consecutive epididymal sparing bilateral simple orchiectomy (BSO) procedures that were performed at the Atlanta Veterans Affairs Medical Center during a 25-month period. All patients had pathologically confirmed prostate cancer. A total of 52 patients (57.1%) were receiving LH-RH agonist therapy prior to the procedure and the remaining 39 (42.9%) were not. All procedures were performed in an outpatient clinic setting using spermatic cord anesthesia block as the only method of anesthesia. In the 52 patients who were on LH-RH agonist therapy prior to the procedure the overall impression/satisfaction with the procedure was evaluated using a questionnaire. RESULTS: All 91 procedures were performed at the urology outpatient clinic using local anesthesia. Mean patient age was 74.2 years (range 44 to 86). Mean serum prostate specific antigen was 58.9 ng/ml. The mean time required to perform the spermatic cord anesthesia block was 3.9 minutes (range 2 to 6) and the volume of anesthetic solution was 18.9 ml per case (range 10 to 32). Despite significant difference in testicular size between patients receiving and not receiving LH/RH agonists there were no differences in anesthesia time or anesthetic volume (3.9 and 3.9 minutes, p = 0.97, and 18.6 and 19.4 ml, respectively, p = 0.47). Mean operative time for BSO excluding anesthesia time was 36.9 minutes (range 18 to 70). Mean operative time was similar in patients receiving and not receiving LH-RH agonists (36.2 and 37.8 minutes, respectively, p = 0.39). The procedure was well tolerated, as judged by the mean intraoperative pain score during BSO of 0.2 (range 0 to 3). The majority of patients (76 or 83.5%) were pain-free during the procedure. Pain scores were similar in patients who were and were not receiving LH-RH agonists during BSO (p = 0.97). There were no adverse events. Followup data were available on 26 of the 52 patients who were receiving LH-RH agonist therapy prior to the procedure. Of them 96.2% were satisfied with the results and 84.6% preferred the procedure over medical castration therapy with LH-RH agonist therapy. CONCLUSIONS: Epididymal sparing bilateral simple orchiectomy is a simple and safe procedure that can be conveniently performed in an outpatient clinic setting using pure local anesthesia. Preservation of the epididymis and subsequent epididymoplasty is effective for maintaining the esthetic appearance of the scrotum and patient satisfaction. The procedure offers patients the convenience of 1-time surgical therapy over lifelong medical injection therapy at a significantly lower cost and without significantly compromising the esthetic appearance of the scrotum.     

Observed environmental features and the physical activity of adolescent males

BACKGROUND: It has recently been reported that adult physical activity was associated with environmental features. The aim of this study was to determine whether environmental features were associated with physical activity among male adolescents. METHODS: Physical activity levels of 210 Boy Scouts were assessed for 3 days by accelerometry during 2003 and 2004. Mean minutes of sedentary, light, and moderate-to-vigorous intensity activity were calculated. Environmental features within a 400-meter radius of each participant's home address were assessed by direct observation using the Systematic Pedestrian and Cycling Environmental Scan (SPACES) instrument. Principal component factor analysis reduced the 35 SPACES items to four factors. Hierarchical and spatial regressions were conducted with physical activity as the dependent variable and environmental factors, age, body mass index, and ethnicity as independent variables. RESULTS: Four factors were obtained: walking/cycling ease, tidiness, sidewalk characteristics, and street access and condition. Sidewalk characteristics were negatively associated with minutes of sedentary behavior while age was positively associated. Sidewalk characteristics were positively associated with minutes of light-intensity physical activity and age negatively associated. No environmental factor correlated with moderate-to-vigorous physical activity. CONCLUSIONS: A sidewalk characteristics factor, composed of sidewalk location, sidewalk material, presence of streetlights, and number and height of trees, was positively associated with light-intensity physical activity among male adolescents.