The cytotoxic activity of amino (3a-e), aza-1-antraquinone (4a-e) lapachol derivatives against Ehrlich carcinoma and human K562 leukemia cells was investigated. Cell viability was determined using MTT assay, after 48 (Ehrlich) or 96 h (K562) of culture, and vincristine (for K562 leukemia) and quercetin (for Ehrlich carcinoma) were used as positive controls. The results showed dose-dependent growthinhibiting activities and that the amino derivatives were active against the assayed cells, whereas the 4a-e derivatives were not. The allylamine derivative 3a was the most active against Ehrlich carcinoma, with IC 50 = 16.94 ± 1.25 µM, and against K562 leukemia, with IC 50 = 14.11 ± 1.39 µM. The analogous lawsone derivative, 5a, was also active against Ehrlich carcinoma (IC 50 = 23.89 ± 2.3 µM), although the 5d and 5e derivatives showed lower activity. The interaction between 3a-d and calf thymus DNA was investigated by fluorimetric titration and the results showed a hyperchromic effect indicating binding to DNA as presented of ethidium bromide, used as positive control. The inhibitory action on DNA-topoisomerase II-α was also evaluated by a relaxation assay of supercoiled DNA plasmid, and the etoposide (200 µM) was used as positive control. Significant inhibitory activities were observed for 3a-d at 200 µM and a partial inhibitory action was observed for lapachol and methoxylapachol.

Objective: This study evaluated various physical properties of two resin composites polymerized by either an argon laser or a conventional visible light. Materials and Methods: A hybrid composite, Herculite XRV (Kerr Corp., Orange, California), and a microfill composite, Durafill VS (Kulzer, Wehrheim, Germany), were used in this study. Three physical properties, diametral tensile strength, compressive strength, and flexural strength, were tested. Five specimens of each composite resin were made for each set of physical properties tested, for a total of 18 groups and 90 specimens. Specimens were fabricated according to the American National Standards Institute and American Dental Association Specification No. 27 for each property tested. The composite was polymerized with either an argon laser (power density of 1000 mW/cm2) for 10 or 20 seconds or a conventional visible light (power density of 354 mW/cm2) for 40 seconds. Specimens were stored in water in light‐proof containers at 37°C for 7 days before testing with a Zwick (Atlanta, Georgia) universal testing machine. Results: The physical properties of Herculite XRV were not affected by the light source or exposure time. For Durafill VS, no significant differences were observed for the diametral tensile strength whether the argon laser or conventional light was used. However, the flexural strength of the microfill was significantly lower when polymerized with the argon laser a t 10 seconds compared with the two other curing methods (20‐second laser cure, 40‐second conventional cure). Also, the compressive strength of Durafill VS polymerized with the argon laser a t 10 seconds was significantly lower than when it was cured with the conventional light for 40 seconds. Conclusions: Hybrid and microfill resin composites cured with an argon laser for 20 seconds had physical properties comparable to composites polymerized with a conventional visible light unit for 40 seconds. Therefore, with adequate exposure time, the argon laser is a potential alternative to conventional visible light‐curing.

SUMMARYThe objective of the study was to evaluate the effect of supplementation with starch or fibre-based concentrates on blood metabolites in dairy cows fed spring pasture. Twenty seven lactating Friesian cows producing 30.0 L/day were assigned to completely randomized design for 42 days. The treatments included: Grazing alone (TG), grazing plus 6 kg/d of sugar beet pulp-based concentrate (TA) and grazing plus 6 kg/d of cereal-based concentrate (TF). The cows were supplemented twice a day and managed under a strip grazing system on pasture consisting mainly of perennial ryegrass. Six coccigeal blood samples from each cow were obtained for seven consecutive days after the morning milking in vacuum tubes containing sodium heparin and sodium fluoride. Plasma was separated after centrifugation, frozen at -25ºC and analyzed for βOH-butyrate, glucose, urea and albumin. The unsupplemented group had a lower glycaemia and a higher βOH-butyrate concentrations than TA and TF (P < 0.05). It was observed a prevalence of 44% sub clinical ketosis in TP group, and no cases in TA or TF. The glycaemia were higher in TA (P < 0.05). The plasmatic urea concentrations were lower (P < 0.05) in TS and higher in TG (P < 0.05). Among the treatments not differences were found for the plasmatic albumin concentrations (P>0.05). From the results it can be concluded that supplementation with starch concentrate advantage the energetic balance in lactating dairy cows at pasture. The supplementation with concentrate based on starch or fibre decreased the risk of sub clinical ketosis, and increase the utilization of pasture nitrogen reducing plasma urea concentrations.Palabras clave: vacas, pastoreo, suplementación, metabolismo.

The advanced scheduling of patients for elective surgeries is challenging when the operating room capacity usage by these procedures is uncertain. We study the application of some revenue management concepts and techniques to operating rooms for several surgical procedures performed in a multi-tier reimbursement system. Our approach focuses on booking requests for elective procedures, under the assumption that each request uses a random amount of time. We create and use a modified version of Belobaba's well-known EMSRb algorithm (Belobaba 1989) to decide on near-optimal protection levels for various classes of patients. Under the random resource utilization assumption, we decide, for each planning horizon, how much time to reserve for satisfying the demand coming from each class of patients, based on the type of surgical procedure requested and the patient's reimbursement level.

The glycosylated collagen- and laminin-binding surface adhesin Cnm is present in approximately 20% of S. mutans clinical isolates and is associated with systemic infections and increased caries risk. Other surface-associated collagen-binding proteins of S. mutans such as P1 and WapA have been demonstrated to form an amyloid quaternary structure with functional implications within biofilms. In silico analysis predicted that the b-sheet rich N-terminal collagen-binding domain (CBD) of Cnm has propensity for amyloid aggregation, whereas the threonine-rich C-terminal domain was predicted to be disorganized. In this study, thioflavin-T fluorescence and electron microscopy were used to show that Cnm forms amyloids either in its native glycosylated or recombinant non-glycosylated forms and that the CBD of Cnm is the main amyloidogenic unit of Cnm. We then performed a series of in vitro, ex vivo and in vivo assays to characterize the amylogenic properties of Cnm.  In addition, Congo red birefringence indicated that Cnm is a major amyloidogenic protein of S. mutans biofilms. Competitive binding assays using collagen-coated microtiter plates and dental roots, a substrate rich in collagen, revealed that Cnm monomers inhibit S. mutans binding to collagenous substrates whereas Cnm amyloid aggregates lose this property. Thus, while Cnm contributes to recognition and initial binding of S. mutans to collagen-rich surfaces, Cnm amyloid aggregation appears to represent a mechanism to modulate this activity in mature biofilms.