Rubber friction and the effect of shape

Contrary to the classic laws of friction, rubber friction is not independent of shape. The friction of three shapes of the same rubber compound sliding over a dry-rough surface was measured. The three shapes had the same nominal contact area but different sliding direction-lengths and widths. Frictional differences were found between all three shapes at sliding speeds of 10 mm/s and 0.5 mm/s. The effect of frictional heating and other friction mechanisms that cause these differences are evaluated and discussed

Concurrent chemoradiotherapy with low dose weekly gemcitabine in stage III non-small cell lung cancer

BACKGROUND: Combined chemoradiotherapy (CRT) is the treatment of choice for stage III NSCLC. Gemcitabine (G) is a novel deoxycitidine analogue that has been proven to be a potent radiosensitizer. Twenty-two consecutive patients were treated with concurrent CRT to demonstrate the tolerability and efficacy of low dose G given weekly as radiosensitizer in stage III NSCLC. METHODS: Patients with KPS ≥70, adequate bone marrow reserve, with no prior radiotherapy (RT) and surgery were included. Eighteen patients had received prior induction chemotherapy (CT). G (75 mg/m(2)/week) was infused over 1 hour for 6 weeks. Thoracic RT was given two hours later over 6 weeks at 1.8 Gy/day fractions (total dose of 61.2 Gy). Pulmonary toxicity was evaluated with computed tomography scans in 6 weeks. RESULTS: Median age was 60 years (range, 48–75), median follow-up was 15 months (range, 2–40). Sixty-eight percent of patients were male and median KPS score was 90. Conformal 3D-RT planning was used in 64% of patients. G was given for a median of 5 weeks (range 1–9). Twelve patients (54.6%) received all planned CT. G was stopped because of intolerance in 6 and death in 2 patients. Seven patients (31.8%) had radiation pneumonitis. Twenty patients were evaluated for overall response, 1 patient (4.5%) had clinical CR, 81.8% had PR while 9.5% had SD. Median overall survival (OS) was 14 ± 5 months (95% CI 3–25). One- and 2-year OS rates were 55% and 38%. Sixteen patients died of disease-related events (6 with progression of primary tumor, 8 due to metastatic disease), 2 patients died of other causes. One- and 2-year progression-free survival and local control rates were 56%, 27% and 79%, 51%, respectively. CONCLUSION: G might be used as radiosensitizer for patients with stage III NSCLC who could not receive full doses CT with concurrent RT

Stress-induced adaptive morphogenesis in bacteria

Bacteria thrive in virtually all environments. Like all other living organisms, bacteria may encounter various types of stresses, to which cells need to adapt. In this chapter, we describe how cells cope with stressful conditions and how this may lead to dramatic morphological changes. These changes may not only allow harmless cells to withstand environmental insults but can also benefit pathogenic bacteria by enabling them to escape from the immune system and the activity of antibiotics. A better understanding of stress-induced morphogenesis will help us to develop new approaches to combat such harmful pathogens.Microbial Biotechnolog

Pre emptive analgesia for reducing pain after cholecystectomy: Oral tramadol vs. acetaminophen codeine

Background: Considering that protocols of postoperative pain management would be planned regarding the facilities of each center or region and the importance of its proper management to reduce its related complication and improve patient′s satisfaction, in this study we compared the effect of orally administrated tramadol and acetaminophen-codeine in this regard. Materials and Methods: In this prospective randomized double-blind clinical trial, 136 (68 in tramadol and 68 in acetaminophen codeine groups) ASA I and II patients scheduled for open cholecystectomy under general anaesthesia were enrolled. They randomly allocated to receive oral tramadol (50 mg capsule) or acetaminophen-codeine (325/10 mg) 1 hour before surgery. After surgery they evaluated for postoperative pain using VAS score, analgesic consumption and vomiting. Results: Mean of postoperative pain score during 24 hours after surgery was 2.1 ± 1.0 and 3.8 ± 2.0 in tramadol and acetaminophen-codeine groups, respectively (P < 0.05). Mean of analgesic consumption (morphine) during 24 hours after surgery was 6.2 ± 4.4 mg and 12.9 ± 5.7 mg in tramadol and acetaminophen-codeine groups, respectively (P < 0.05). Mean of vomiting during 24 hours after surgery was 1.2 ±0.9 and 0.4 ± 0.5 in tramadol and acetaminophen-codeine groups, respectively (P < 0.05). Conclusion: The findings of current study indicated that in lower dose of tramadol (50 mg) and acetaminophen/codeine (325 mg/10 mg) the analgesic effect of tramadol is better and its side effects are higher than acetaminophen/codeine, which limit its use for mentioned purpose. It seems that administration of each of studied agents it depends on patients′ tolerance and decision of the physician