Critical evaluation of the indentation data analyses methods for the extraction of isotropic uniaxial mechanical properties using finite element models

Two different definitions of indentation strain and two different definitions of contact radius are being used in the current literature, leading to inconsistent estimates of mechanical properties (especially plastic properties). In this paper, we critically evaluate the validity of the different definitions of both the indentation strain and the contact radius by applying the protocols on datasets generated from a finite element simulation of spherical indentation. The finite element models allow assignment of a wide range of elastic–plastic properties to the sample while circumventing many of the uncertainties faced in experimental investigations, and thereby offer unique opportunities for critical validation of the different data analysis procedures. In particular, we are able to establish important connections between the indentation stress–strain curves and the conventional uniaxial stress–strain curves.     

Coherent Smith-Purcell radiation: Theories and simulations

Smith-Purcell (SP) radiation has been observed many times over the past fifty years, and several theories have been proposed to explain it. However, it is only quite recently that Andrews, Brau and collaborators made a considerable advance in understanding how coherent SP radiation may be produced from an initially continuous beam. Their work received support from 2-D simulations which were performed using the Particle-in-Cell (PIC) code “MAGIC”. Here we present a review of our 2-D simulations of coherent SP and discuss how they relate to the model of Andrews and Brau. We also describe briefly a SP experiment in the microwave domain using a sheet beam that is planned for 2008.     

Pyridylamino‐β‐cyclodextrin as a Molecular Chaperone for Lipopolysaccharide Embedded in a Multilayered Polyelectrolyte Architecture

Layer‐by‐layer self‐assembled polyelectrolyte films containing a charged cyclodextrin and lipopolysaccharide (LPS) are developed for the first time as a potential model for local endotoxin antagonist delivery. We have examined the biological activity of a lipopolysaccharide from E. coli incorporated into multilayered architectures made of poly‐(L ‐lysine) and poly‐(L ‐glutamic acid). Used in such build‐ups, a polycationic cyclodextrin, heptakis(6‐deoxy‐6‐pyridylamino)‐β‐cyclodextrin showed molecular chaperone properties by enabling restoration of the LPS biological activity whenever lost upon interaction with poly‐(L ‐lysine).     

Laparoscopic biopsy for suspected abdominal lymphoma

This study retrospectively reviewed the findings in laparoscopic biopsy specimens from 51 consecutive patients with suspected abdominal lymphoproliferative disorders. Histologic evaluation was supplemented (as necessary) by paraffin-section or frozen-section immunohistochemical analysis or by Southern blot hybridization. The laparoscopic procedure was diagnostic of a lymphoproliferative disorder in 24 patients (47%), of other neoplasms in 5 patients (10%), and of reactive tissue in 11 patients (22%); no tissue could be obtained for technical reasons (adhesions and inaccessible lesions) in 11 patients (22%). The 24 patients with lymphoproliferative disorders diagnosed by laparoscopic techniques included 14 patients with a new diagnosis of lymphoma and 10 patients with recurrent disease; pathologic findings were diagnostic of diffuse large cell lymphoma (11 patients), follicular lymphoma (11 patients), chronic lymphocytic leukemia (1 patient), and lymphocyte-predominant Hodgkin's disease (1 patient). Previous abdominal cytologic or core-needle biopsy specimens from 11 lymphoma patients did not yield an unequivocal diagnosis or subtype of lymphoma. The 11 patients (22%) in whom laparoscopic techniques did not produce a tissue sample needed laparotomy (10 patients) or femoral lymph node biopsy (1 patient) to document the diagnosis of large cell lymphoma (2 patients), follicular lymphoma (5 patients), composite lymphoma (1 patient), myeloma (1 patient), neurofibroma (1 patient), and reactive lymph nodes (1 patient). In the majority of patients with suspected abdominal lymphoma, laparoscopic techniques provide sufficient tissue for the diagnosis and classification of lymphoma and for the diagnosis of other causes of abdominal lymphadenopathy.     

Predictive parameters of biologic behavior of early stage nonseminomatous testicular germ cell tumors

BACKGROUND: Thirty percent of patients presenting with clinical stage A nonseminomatous testicular germ cell tumors in fact have pathologic stage B disease. This pilot study was performed to determine whether DNA content and cell cycle analysis by flow cytometry and single-cell cytophotometry can improve clinical staging in these patients. METHODS: The orchiectomy specimens of 102 patients with clinical stage A disease were analyzed retrospectively using histopathologic classification, flow cytometry, and single-cell cytophotometry. All patients had undergone retroperitoneal lymph node dissection. RESULTS: The multivariate analysis in this group of patients resulted in the following model: If the primary tumor consisted of 100% embryonal carcinoma, the patient was classified as high risk for retroperitoneal metastasis. If the patient was found to have less than 100% embryonal carcinoma in the primary tumor, the percent of aneuploid tumor cells in S-phase as identified by flow cytometry was most predictive for pathologic stage. Using this approach, 91% of all patients with pathologic stage B, and 77% of the patients with pathologic stage A were correctly classified; test efficiency was 82%. CONCLUSIONS: These results demonstrate an improvement in clinical staging in this group of patients. This paradigm, developed from retrospective analysis, will be tested prospectively in consecutive patients to determine if it is clinically useful.     

Lower limb amputation 2: once the decision to amputate has been made

This is the second of four articles on lower limb amputation. The first article (Vol 6(17): 970-7) discussed the indications for amputation and briefly outlined the treatment options that may be tried before the amputation stage is reached. This second article examines the factors that need to be addressed once the decision to amputate has been made. It stresses the importance of preparing the patient and his/her family both psychologically and physiologically for the operation. The techniques and rationale for selecting the optimum level of amputation are then discussed. Finally, the specific levels of lower limb amputation are outlined. The next article in this series will explore the nurse's role in preparing the patient for an amputation, and the final article will address the issues raised when a patient decides that death is preferable to living as an amputee.     

Residual masses after chemotherapy for metastatic testicular cancer: the clinical implications of the association between retroperitoneal and pulmonary histology. Re-analysis of Histology in Testicular Cancer (ReHiT) Study Group

PURPOSE: We determined the need and sequence of retroperitoneal lymph node dissection and thoracotomy in patients with nonseminomatous testicular cancer, and with residual retroperitoneal and pulmonary masses after chemotherapy. MATERIALS AND METHODS: We studied 159 patients undergoing retroperitoneal lymph node dissection and a thoracotomy following cisplatin based induction chemotherapy for metastatic testicular nonseminomatous germ cell tumor. Several well-known predictors for residual histology (necrosis, mature teratoma and cancer) were evaluated. RESULTS: As expected, necrosis was found more often at retroperitoneal lymph node dissection if the primary tumor was negative for teratoma, the residual mass was small or the decrease in size was great. Contrary, neither residual mass size nor the decrease in size was predictive of the histological status of the residual lung lesion. Histological findings in the retroperitoneum and lung were strongly correlated, such that necrosis at retroperitoneal lymph node dissection was associated with an 89% probability of necrosis in the lung. CONCLUSIONS: Retroperitoneal lymph node dissection should be performed before thoracotomy is considered, since the histological status at dissection is a strong predictor of that at thoracotomy.     

Toward a “grand unifying theory” of leadership: Implications for consulting psychology.

A succinct overview of some of the major research approaches to the study of leadership is provided as a foundation for the introduction of a multicomponent model of leadership that draws on those findings, complexity theory, and the concept of emergence. The major aspects of the model include: the personal characteristics and capacities, thoughts, feelings, behaviors, and human working relationships of leaders, followers, and other stake holders, the organization's systems, including structures, processes, contents, and internal situations, the organization's performance and outcomes, and the external environment(s), ecological niches, and external situations in which an enterprise functions. The relationship between this model and other approaches in the literature as well as directions in research on leadership and implications for consulting practice are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Intoxication level and emotional response.

We used affective modulation of the eye-blink component of the startle reflex to examine effects of three levels of alcohol intoxication and a no-intoxication control on emotional responses to pleasant, neutral, and unpleasant pictures. Non-problematic student drinkers (n = 101; 48 female) were randomly assigned to intoxication groups. Normal inhibition of startle during exposure to pleasant pictures was intact across groups. In contrast, potentiation of startle during viewing of unpleasant pictures was evident in the no- and low-intoxication groups, compared to the intermediate- and high-intoxication groups, in which it was significantly reduced. This pattern suggests that a direct and selective anxiolytic effect of alcohol can occur at higher levels of intoxication without an analogous impact on response to emotionally positive stimuli at similar levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved)