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The fatigue crack growth behavior of a submicron-grained WC–Co hardmetal is investigated by artificially introducing small flaws by means of sharp indentation. Similar fatigue testing is also conducted on notched specimens with long through-thickness cracks for comparison purposes. The use of controlled small indentations flaws is shown to be a valid and successful approach for studying and describing crack growth behavior under cyclic loading for the material under consideration. This statement is based on the similitude found in fatigue mechanics and mechanisms between both crack types. Regarding the former, accounting of the indentation-induced residual stresses is key to rationalize the experimental findings. Concerning the latter, inspection of crack-microstructure interaction as well as fracture surfaces permit to discern similar features and scenarios, at both meso- and micrometric length scales. Results from this research yield an immediate practical implication, as indentation techniques may then be proposed as an alternative testing route for investigating fatigue crack growth behavior of hardmetal grades where sharp indentation is capable to induce well-developed radial crack systems. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of an Enhanced Recovery After Surgery (ERAS) program on complications and length of stay (LOS) after radical cystectomy (RC) and to assess if the number and type of components of ERAS play a key role on the decrease of surgical morbidity. Materials and methods: We analyzed the data of 277 patients prospectively recruited in 11 hospitals undergoing RC initially managed according to local practice (Group I) and later within an ERAS program (Group II). Two main outcomes were defined: 90-day complications rate and LOS. As secondary variables we studied 90-day mortality, 30-day readmission and transfusion rate. Results: Patients in Group II had a higher use of ERAS measures (98.6%) than those in Group I (78.2%) (p < 0.05). Patients in Groups I and II experienced similar complications (70.5% vs. 66%, p = 0.42). LOS was not different between Groups I and II (12.5 and 14 days, respectively, p = 0.59). The risk of having any complication decreases for patients having more than 15 ERAS measures adopted [RR = 0.815; 95% confidence interval (CI) 0.667–0.996; p = 0.045]. Avoidance of transfusion and nasogastric tube, prevention of ileus, early ambulation and a fast uptake of a regular diet are independently associated with the absence of complications. Conclusions: Complications and LOS after RC were not modified by the introduction of an ERAS program. We hypothesize that at least 15 measures should be applied to maximize the benefit of ERAS [ABSTRACT FROM AUTHOR]

This work examines mechanical properties of 50–300 nm gold thin films deposited onto micrometer-thick flexible polymer substrates by means of tensile testing of the film–substrate system and modeling. The film properties are extracted from mechanical testing of the film–substrate system and modeling of the bimaterial. Unlike materials in bulk geometry, the film elastic modulus and yield strength present an important dependence with film thickness, with modulus and yield strength of about 520 and 30 GPa, respectively, for the thinner films and decreasing toward the bulk value as the film thickness increases. The relation between grain size, film thickness, and yield strength is examined. Finite element analysis provides further insight into the stress distribution in the film–substrate system. [ABSTRACT FROM AUTHOR]

Cyclic deformation of a superduplex stainless steel at temperatures ranging from room temperature to 475 °C was evaluated for two different strain amplitudes. Cyclic hardening-softening response and the corresponding substructural features within each constituent phase of the alloy were characterized. Experimental evidence, such as abnormal cyclic hardening, inverse strain rate sensitivity (SRS), and serrated flow, reveals the existence of dynamic strain aging (DSA) in the studied temperature range. Substructural evolution suggests that DSA induces changes in the distribution of plastic strain between austenite and ferrite. In the case of tests performed at 475 °C, there exists a significant influence of thermal embrittlement too. [ABSTRACT FROM AUTHOR]

Electrical discharge machining (EDM) is an alternative-shaping route for manufacturing complex component shapes of hard and brittle materials such as hardmetals (WC-Co cemented carbides). It is well established that in these materials EDM typically induces a heat affected surface layer with poor integrity. This degradation effect may be compensated through specific post-EDM surface treatments either by thermomechanical means or material surface deposition. In the latter case, a key property for optimal performance is the level of coating to substrate adhesion and how this is affected by the EDM-induced surface. The main objective of this investigation was to evaluate the adhesion strength of TiN coatings on EDMed hardmetals. A series of hardmetal samples that had been subjected to different multi-pass sequential EDM levels were coated with TiN. Adhesion behavior was assessed using the indentation adhesion test and comparing the critical load for crack extension ( P c) and the interfacial fracture toughness ( K Ic,interface) to those exhibited by the TiN coating deposited on a ground and polished substrate (used as baseline control). Experimental results indicated that indentation adhesion increased with finer-executed EDM, almost reaching baseline level values. The results are discussed on the basis of the compromising EDM influence on both surface integrity of the substrate and tortuousness at the interface, the latter resulting in mechanical anchoring of the TiN coating to the hardmetal substrate. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical utility of using the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify prostate-specific antigen (PSA) mRNA in peripheral blood samples from patients with prostate cancer as a predictor of extraprostatic extension of the disease and to assess any correlations with known predictive markers of this condition.Methods: Immediately before radical prostatectomy, peripheral blood samples were taken from 42 men with clinically localized prostate cancer and analysed for PSA and 18S ribosomal (endogenous control) genes using real-time RT-PCR (with gene expression assays and the comparative CT–cycle threshold—method for quantifing). A total of 30 healthy male blood donors aged <50 y was taken as a control group.The relationships between PSA mRNA values, pathological and clinical features were analysed. PSA mRNA value, PSA level and biopsy Gleason score were then compared as predictors of extraprostatic extension.Results: PSA gene expresion was 3.73 times significantly higher in patients with clinically localized prostate cancer than in healthy men (P<0.05). There was no relationship between PSA real-time RT-PCR values and pathological stage pT2 or pT3 (P=0.5), and no association between PSA mRNA value and serum PSA level (P=0.9) or the Gleason score of the preoperative biopsy (P=0.9).Conclusion: There was no significant advantage in using the real-time RT-PCR assay of PSA mRNA before surgery to stage prostate cancer and to discriminate between organ-confined and extraprostatic extension.Prostate Cancer and Prostatic Diseases (2005) 8, 248–252. doi:10.1038/sj.pcan.4500801; published online 17 May 2005 [ABSTRACT FROM AUTHOR]

The objective of this paper is to validate prostate specific antigen (PSA) density (PSAD) routine use to enhance PSA specificity in men with normal digital rectal examination and intermediate PSA values. It is a retrospective study of 235 men from a prostate cancer (PCa) screening program. All of them presented PSA values between 4 and 10 ng/ml, normal digital rectal examination, and a transrectal ultrasound (TRUS) guided biopsy available (PSA≥4 ng/ml as the sole criterion for biopsy). Multivariate analysis failed to demonstrate higher PSAD values in men with PCa. PSAD cutoff points higher than 0.07 ng/ml per cc were considered as unacceptable, with less than 95% sensitivity. When a cutoff point of 0.15 was considered, as many as 30.6% of the cancers were missed. In conclusion we cannot recommend the use of this parameter for the above mentioned purpose.Prostate Cancer and Prostatic Diseases (2001) 4, 146–149. [ABSTRACT FROM AUTHOR]

An assessment of fracture origins is conducted in yttria-stabilized zirconia ceramics containing different grain sizes. As the microstructure coarsens due to the application of heat treatments, fracture origins change from single pores to transformed regions at the free surface which are induced by the applied stress. The observation of an increasing size of failure origins with microstructural coarsening lies as the underlying reason for the finding that specimens containing coarser microstructures and a more pronounced R-curve behavior do not fail at larger stresses. A fracture model is used to link the strength variability of a fully tetragonal zirconia containing a small grain size to its pore size distribution. The increased transformability of zirconia ceramics with coarser tetragonal grains is evaluated by means of quantitative phase analysis, characterizations of fracture surface morphology, and R-curve assessments. It is confirmed that tetragonal grains of up to 4 μm may not necessarily undergo a spontaneous t–m transformation upon cooling from sintering. [ABSTRACT FROM AUTHOR]