[Application of transbronchial cryobiopsy in the diagnosis of postoperative complications after lung transplantation: a report of 6 cases]

Objective: To investigate the efficacy and safety of transbronchial cryobiopsy (TBCB) after lung transplantation. Methods: The clinical characteristics, TBCB procedure, diagnosis and treatment, and outcomes of lung transplant recipients of 6 patients (all male, aged 33-67 years) with TBCB in China-Japan Friendship Hospital from May to November 2021 were retrospectively analyzed. Results: Among the 6 patients diagnosed by TBCB, there were 2 cases of organizing pneumonia, 1 acute cellular rejection, 1 antibody-mediated rejection, and 1 bronchiolitis obliterans, and 1 diffuse alveolar damage. After the clinical diagnosis was confirmed, the condition improved after adjustment of the treatments followed. There were no serious complications related to the TBCB procedure. Conclusion: TBCB is valuable and relatively safe in the diagnosis of complications after lung transplantation, but the indications need to be strictly controlled.

ACR Appropriateness Criteria® Radiologic Management of Mesenteric Ischemia: 2022 Update

Mesenteric ischemia is a serious medical condition characterized by insufficient vascular supply to the small bowel. In the acute setting, endovascular interventions, including embolectomy, transcatheter thrombolysis, and angioplasty with or without stent placement, are recommended as initial therapeutic options. For nonocclusive mesenteric ischemia, transarterial infusion of vasodilators, such as papaverine or prostaglandin E1, is the recommended initial treatment. In the chronic setting, endovascular means of revascularization, including angioplasty and stent placement, are generally recommend, with surgical options, such as bypass or endarterectomy, considered alternative options. Although the diagnosis of median arcuate ligament syndrome remains controversial, diagnostic angiography can be helpful in rendering a diagnosis, with the preferred treatment option being a surgical release. Systemic anticoagulation is recommended as initial therapy for venous mesenteric ischemia with acceptable rates of recanalization. If anticoagulation fails, transcatheter thrombolytic infusion can be considered with possible adjunctive placement of a transjugular intrahepatic portosystemic shunt to augment antegrade flow. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Circadian nuclear receptor Rev-erbalpha is expressed by platelets and potentiates platelet activation and thrombus formation

Background

Adverse cardiovascular events have day/night patterns with peaks in the morning, potentially related to endogenous circadian clock control of platelet activation. Circadian nuclear receptor Rev-erbα is an essential and negative component of the circadian clock.

Purpose

We aim to investigate the expression profile and biological function of Rev-erbα in platelets.

Methods and results

Here we report the presence and functions of circadian nuclear receptor Rev-erbα in human and mouse platelets. Both human and mouse platelet Rev-erbα showed a circadian rhythm that positively correlated with platelet aggregation. Global Rev-erbα knockout and platelet-specific Rev-erbα knockout mice exhibited defective in hemostasis as assessed by prolonged tail-bleeding times. Rev-erbα deletion also reduced ferric chloride-induced carotid arterial occlusive thrombosis, prevented collagen/epinephrine-induced pulmonary thromboembolism, and protected against microvascular microthrombi obstruction and infarct expansion in an acute myocardial infarction model. In vitro thrombus formation assessed by CD41-labeled platelet fluorescence intensity was significantly reduced in Rev-erbα knockout mouse blood. Platelets from Rev-erbα knockout mice exhibited impaired agonist-induced aggregation responses, integrin αIIbβ3 activation and α-granule release. Consistently, pharmacological inhibition of Rev-erbα by specific antagonists decreased platelet activation markers in both mouse and human platelets. Mechanistically, mass spectrometry and co-immunoprecipitation analyses revealed that Rev-erbα potentiated platelet activation via oligophrenin-1-mediated RhoA/ERM (ezrin/radixin/moesin) pathway.

Conclusion

We provide the first evidence that circadian protein Rev-erbα is functionally expressed in platelets and potentiates platelet activation and thrombus formation. Rev-erbα may serve as a novel therapeutic target for managing thrombosis-based cardiovascular disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by grants from the National Science Fund for Distinguished Young Scholars (81625002), the National Natural Science Foundation of China (81930007).

ERBB2 gene expression silencing involved in ovarian cancer cell migration and invasion through mediating MAPK1/MAPK3 signaling pathway

OBJECTIVE

To explore possible mechanism of ERBB2 gene expression silencing mediating mitogen-activated protein kinase 1/mitogen-activated protein kinase 3 (MAPK1/MAPK3) signaling pathway on proliferation, migration, and invasion of ovarian cancer cells.

PATIENTS AND METHODS

A total of 240 cancer specimens were collected in patients with epithelial ovarian cancer intraoperatively in our hospital from January 2015 to January 2018. Expressions of ERBB2, MAPK1, and MAPK3 in tissues were detected by immunohistochemistry. Following the culture of ovarian cancer cell lines, target cell line with high expression of ERBB2 was screened by qRT-PCR. Cell grouping was performed with four groups after transfection, including Blank group, negative control (NC) group, ERBB2 shRNA group, and ERBB2 overexpression group (shorted as ERBB2 group). The expression levels of ERBB2, MAPK1, MAPK3, vascular endothelial growth factor (VEGF), metalloproteases-2 (MMP-2), and tissue inhibitor of metalloproteases-2 (TIMP-2) were detected by qRT-PCR in different transfection groups, followed by the detection of protein expressions with Western blot. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to test the proliferation activity of each group after transfection, while transwell assay and scratch test explored cell invasion and migration in each group, respectively.

RESULTS

Immunohistochemistry showed that the positive rates of ERBB2, MAPK1, and MAPK3 in ovarian cancer tissues were significantly increased than those in adjacent normal epithelial tissues. In the cell experiment, ERBB2 gene was highly expressed in SKOV3 ovarian cancer cell line. There was no significant difference in each index between Blank group and NC group (p > 0.05). Compared with Blank group and NC group, the expression levels of ERBB2, MAPK1, MAPK3, VEGF, and MMP-2 in ERBB2 shRNA group decreased significantly, TIMP-2 increased markedly, and proliferation, invasion, and migration abilities of cells decreased markedly after transfection, showing statistically significant differences (All p < 0.05). By contrast, the expression levels of ERBB2, MAPK1, MAPK3, VEGF, and MMP-2 increased remarkably in ERBB2 group, while TIMP-2 decreased significantly, and cell proliferation, invasion, and migration ability increased evidently after transfection, with statistically significant differences (All p < 0.05).

CONCLUSIONS

Silencing ERBB2 gene expression may inhibit the activation of MAPK1/MAPK3 signaling pathway and thus suppress the proliferation, invasion, and migration of ovarian cancer cells. Overexpression of ERBB2 gene can reverse those trends, which in turn support the role of ERBB2 gene expression silencing in molecular targeted therapy of ovarian cancer.

Professional and interprofessional identities: a scoping review

Identity development within the interprofessional field is an emerging area of research. This scoping review aims to establish how professional and interprofessional identities are defined, conceptualized, theorized and measured within the interprofessional literature. Six databases were systematically searched for papers focusing on professional and/or interprofessional identities in interprofessional healthcare and education using a scoping review methodology. A total of 84 papers were included. Most papers discussed professional identity only; the minority discussed both identities. There were three key findings. First, no universal definition of interprofessional identity exists. Second, there is no shared understanding of interprofessional identity and its relationship with professional identity. Third, poor alignment between definitions, conceptualizations, theories and measures of interprofessional identity exists. The absence of a psychometrically robust instrument that specifically measures interprofessional identity and the short-term focus of current interprofessional identity research further limits understanding. Research that critically examines professional and interprofessional identity development should be underpinned by clear definitions, concepts, theories and measures of both identities. High-quality research will allow greater understanding of interprofessional identity development and its impact on interprofessional practice.

[Diagnostic value of endobronchial ultrasonography with a guide sheath for peripheral pulmonary ground glass opacity]

Objective: To explore the diagnostic value of endobronchial ultrasonography with a guide sheath (EBUS-GS) for peripheral pulmonary ground glass opacity (GGO). Methods: The clinical data of 27 consecutive patients with 27 GGOs diagnosed by EBUS-GS between November 2014 to December 2015 in our Cancer Hospital were retrospectively analyzed. The average age of these 27 patients, including 9 males and 18 females, was 59±11 years. The median lesion size of the 27 GGOs was 2.9±1.2 cm, including 24 mixed GGOs and 3 pure GGOs. EBUS images of all 27 GGOs were evaluated, cytological, histological and combination diagnosis analyzed, and complications observed. Results: Under thin bronchoscope, 2 out of 27 cases showed bronchial stenosis, 1 showed bronchial stenosis with mucosal swelling, and the other 24 did not show abnormalities. Twenty-five out of 27 GGOs were found by EBUS, including 22 cases of mGGO and 3 of pGGO. In these ultrasonic images of 22 mGGOs, 18 showed mixed blizzard sign, 3 showed diffusely heterogeneous acoustic shadow and 1showed blizzard sign. Ultrasonic images of 3 pGGOs all appeared as blizzard sign. Twenty-six cytological specimens were obtained, and 16 were diagnosed clearly. All 27 histological specimens were collected, and 18 were diagnosed clearly. Nineteen of 27 cases were diagnosed by combination of cytological and histological specimens. One complication of EBUS-GS with mild bleeding was observed, and hemorrhage was terminated by conservative treatment. Conclusions: EBUS-GS is valuable for GGO diagnosis with less complications and higher safety. GGO ultrasonic image manifested as mixed blizzard sign, blizzard sign or diffusely heterogeneous acoustic shadow.

A two-component pre-seeded dermal-epidermal scaffold

We have developed a bilayered dermal-epidermal scaffold for application in the treatment of full-thickness skin defects. The dermal component gels in situ and adapts to the lesion shape, delivering human dermal fibroblasts in a matrix of fibrin and cross-linked hyaluronic acid modified with a cell adhesion-promoting peptide. Fibroblasts were able to form a tridimensional matrix due to material features such as tailored mechanical properties, presence of protease-degradable elements and cell-binding ligands. The epidermal component is a robust membrane containing cross-linked hyaluronic acid and poly-l-lysine, on which keratinocytes were able to attach and to form a monolayer. Amine-aldehyde bonding at the interface between the two components allows the formation of a tightly bound composite scaffold. Both parts of the scaffold were designed to provide cell-type-specific cues to allow for cell proliferation and form a construct that mimics the skin environment.

A transgenic tri-modality reporter mouse

Transgenic mouse with a stably integrated reporter gene(s) can be a valuable resource for obtaining uniformly labeled stem cells, tissues, and organs for various applications. We have generated a transgenic mouse model that ubiquitously expresses a tri-fusion reporter gene (fluc2-tdTomato-ttk) driven by a constitutive chicken β-actin promoter. This “Tri-Modality Reporter Mouse” system allows one to isolate most cells from this donor mouse and image them for bioluminescent (fluc2), fluorescent (tdTomato), and positron emission tomography (PET) (ttk) modalities. Transgenic colonies with different levels of tri-fusion reporter gene expression showed a linear correlation between all three-reporter proteins (R²=0.89 for TdTomato vs Fluc, R²=0.94 for Fluc vs TTK, R²=0.89 for TdTomato vs TTK) in vitro from tissue lysates and in vivo by optical and PET imaging. Mesenchymal stem cells (MSCs) isolated from this transgenics showed high level of reporter gene expression, which linearly correlated with the cell numbers (R²=0.99 for bioluminescence imaging (BLI)). Both BLI (R²=0.93) and micro-PET (R²=0.94) imaging of the subcutaneous implants of Tri-Modality Reporter Mouse derived MSCs in nude mice showed linear correlation with the cell numbers and across different imaging modalities (R²=0.97). Serial imaging of MSCs transplanted to mice with acute myocardial infarction (MI) by intramyocardial injection exhibited significantly higher signals in MI heart at days 2, 3, 4, and 7 (p<0.01). MSCs transplanted to the ischemic hindlimb of nude mice showed significantly higher BLI and PET signals in the first 2 weeks that dropped by 4^th week due to poor cell survival. However, laser Doppler perfusion imaging revealed that blood circulation in the ischemic limb was significantly improved in the MSCs transplantation group compared with the control group. In summary, this mouse can be used as a source of donor cells and organs in various research areas such as stem cell research, tissue engineering research, and organ transplantation.

High-resolution, serial intravital microscopic imaging of nanoparticle delivery and targeting in a small animal tumor model

Nanoparticles are under active investigation for the detection and treatment of cancer. Yet our understanding of nanoparticle delivery to tumors is limited by our ability to observe the uptake process on its own scale in living subjects. We chose to study single-walled carbon nanotubes (SWNTs) because they exhibit among the highest levels of tumor uptake across the wide variety of available nanoparticles. We target them using RGD (arginine-glycine-aspartic acid) peptide which directs them to integrins overexpressed on tumor vasculature and on the surface of some tumor cells (e.g., U87MG as used here). We employ intravital microscopy (IVM) to quantitatively examine the spatiotemporal framework of targeted SWNT uptake in a murine tumor model. IVM provided a dynamic microscale window into nanoparticle circulation, binding to tumor blood vessels, extravasation, binding to tumor cells, and tumor retention. RGD-SWNTs bound to tumor vasculature significantly more than controls (P<0.0001). RGD-SWNTs extravasated similarly compared to control RAD-SWNTs, but post-extravasation we observed as RGD-SWNTs eventually bound to individual tumor cells significantly more than RAD-SWNTs (p<0.0001) over time. RGD-SWNTs and RAD-SWNTs displayed similar signal in tumor for a week, but over time their curves significantly diverged (p<0.001) showing increasing RGD-SWNTs relative to untargeted SWNTs. We uncovered the complex spatiotemporal interplay between these competing uptake mechanisms. Specific uptake was delimited to early (1-6 hours) and late (1-4 weeks) time-points, while non-specific uptake dominated from 6 hours to 1 week. Our analysis revealed critical, quantitative insights into the dynamic, multifaceted mechanisms implicated in ligand-targeted SWNT accumulation in tumor using real-time observation.

External auditory canal exostoses in white water kayakers

OBJECTIVE

In this study, the presence and severity of external auditory canal exostoses (EACE) in a group of white water kayakers related to the duration and intensity of kayaking and the number of ear infections reported were identified.

DESIGN

A community-based volunteer cross-sectional study was completed with 92 kayakers (69 men, 23 women; mean (SD) age 29.3 (8.72) years) and 65 control volunteers (37 men, 28 women; mean (SD) age 36.9 (14.9) years). After exclusions, 269 individual ears were examined (154 kayakers and 115 controls). Participants completed a questionnaire and underwent otoscopic examination. Main outcome measures were the presence and severity of EACE, the duration and frequency of kayaking and self-reported ear infections. Exclusion criteria included other cold-water exposure, known ear pathology or poor visualisation of the auditory canal.

RESULTS

The findings demonstrated that 69.5% of kayaker ears and 1.7% of the control group were found to have EACE. Severity of EACE was significantly associated with the duration (p<0.01) and frequency (p<0.05) of kayaking with 90.6% of kayakers that had participated for more than 10 years having evidence of EACE. A significant relationship also existed between the number of self-reported ear infections and the severity of EACE (p<0.01).

CONCLUSION

There is a positive relationship between the duration and frequency of white water kayaking and the presence and severity of EACE and associated ear infections.

Robust 3-D modeling of vasculature imagery using superellipsoids

This paper presents methods to model complex vasculature in three-dimensional (3-D) images using cylindroidal superellipsoids, along with robust estimation and detection algorithms for automated image analysis. This model offers an explicit, low-order parameterization, enabling joint estimation of boundary, centerlines, and local pose. It provides a geometric framework for directed vessel traversal, and extraction of topological information like branch point locations and connectivity. M-estimators provide robust region-based statistics that are used to drive the superellipsoid toward a vessel boundary. A robust likelihood ratio test is used to differentiate between noise, artifacts, and other complex unmodeled structures, thereby verifying the model estimate. The proposed methodology behaves well across scale-space, shows a high degree of insensitivity to adjacent structures and implicitly handles branching. When evaluated on synthetic imagery mimicking specific structural complexities in tumor microvasculature, it consistently produces ubvoxel accuracy estimates of centerlines and widths in the presence of closely-adjacent vessels, branch points, and noise. An edit-based validation demonstrated a precision level of 96.6% at a recall level of 95.4%. Overall, it is robust enough for large-scale application.

Onset of abnormal blood and lymphatic vessel function and interstitial hypertension in early stages of carcinogenesis

Recent improvements in diagnostic methods have opened avenues for detection and treatment of (pre)malignant lesions at early stages. However, due to the lack of spontaneous tumor models that both mimic human carcinogenesis and allow direct optical imaging of the vasculature, little is known about the function of blood and lymphatic vessels during the early stages of cancer development. Here, we used a spontaneous carcinogenesis model in the skin of DNA polymerase eta-deficient mice and found that interstitial fluid pressure was already elevated in the hyperplastic/dysplastic stage. This was accompanied by angiogenic blood vasculature that exhibited altered permeability, vessel compression, and decreased alpha-smooth muscle actin-positive perivascular cell coverage. In addition, the lymphatic vessels in hyperplastic/dysplastic lesions were partly compressed and nonfunctional. These novel insights may aid early detection and treatment strategies for cancer.

Blocking platelet-derived growth factor-D/platelet-derived growth factor receptor beta signaling inhibits human renal cell carcinoma progression in an orthotopic mouse model

Renal cell carcinoma is a highly malignant and often fatal disease of the kidney. It is difficult to treat, often because metastases are common at the time of presentation. Platelet-derived growth factor-D (PDGF-D) is a newly discovered member of the PDGF family; its function in tumor progression is largely unknown. Here, we examined the expression level of PDGF-D in human renal cell carcinoma by immunohistochemical staining using tissue arrays. We showed that human renal cell carcinoma expresses high levels of PDGF-D protein. The human renal cell carcinoma cell line SN12-C was stably transfected with pdgf-d cDNA. Overexpression of PDGF-D in SN12-C cells promoted tumor growth, angiogenesis, and metastasis of human renal cell carcinoma in an orthotopic severe combined immunodeficient (SCID) mouse model. PDGF-D overproduction in SN12-C cells increased the proliferation and migration of mural cells in vitro and improved perivascular cell coverage in vivo. Overexpression of PDGF-D led to increased expression of angiopoietin-1 and matrix metalloproteinase-9 in tumor tissues. ShRNAi and Gleevec were used to block PDGF-D expression and PDGF receptor beta (PDGFRbeta) signaling. Inhibition of PDGF-D expression by short hairpin RNA interference (shRNAi) and blockage of PDGFRbeta signaling by Gleevec inhibited the growth and lung metastasis of SN12-C cells grown orthotopically in SCID mice. Thus, PDGF-D is a potential candidate for controlling the progression of metastatic renal cell carcinoma. This opens up an avenue of investigation into novel therapeutic strategies for the treatment of renal cell carcinoma, including the use of recently developed tyrosine kinase inhibitors, such as Gleevec, which inhibit PDGF activity through inhibition of its receptor tyrosine kinase.

Towards a feminist global bioethics: addressing women's health concerns worldwide

In this paper I argue that a global bioethics is possible. Specifically, I present the view that there are within feminist approaches to bioethics some conceptual and methodological tools necessary to forge a bioethics that embraces the health-related concerns of both developing and developed nations equally. To support my argument I discuss some of the challenges that have historically confronted feminists. If feminists accept the idea that women are entirely the same, then feminists present as fact the fiction of the essential "Woman." Not only does "Woman" not exist, -she" obscures important racial, ethnic, cultural, and class differences among women. However, if feminists stress women's differences too much, feminists lose the power to speak coherently and cogently about gender justice, women's rights, and sexual equality in general. Analyzing the ways in which the idea of difference as well as the idea of sameness have led feminists astray, I ask whether it is possible to avoid the Scylla of absolutism (imperialism, colonialism, hegemony) on the one hand and the Charybdis of relativism (postmodernism, fragmentation, Balkanization) on the other. Finally, after reflecting upon the work of Uma Narayan, Susan Muller Okin, and Martha Nussbaum, I conclude that there is a way out of this ethical bind. By focusing on women's, children's, and men's common human needs, it is possible to lay the foundation for a just and caring global bioethics.

Just caring about women's and children's health: some feminist perspectives

This article addresses the issue of women as primary caregivers to children and the concept of "maternal practice." The idea of maternal practice guides mothers as they learn (1) how to meet their child's physical, psychological, and spiritual needs, and (2) how to make their child socially acceptable. Hindrances to maternal practice include severe poverty and disabilities of the mother. The relationship between maternal practice and the quest for health care in the U.S. is discussed. Maintaining adequate health care is more difficult when parents are poorly educated and/or impoverished. Without proper health care, poor children are less likely to be able to compete with rich children in society. Dental care is also a concern, because proper dental care is fundamental in the maintenance of overall health. Dental care is not a "luxury" but medically necessary care. Solutions include increasing the awareness of such programs as CHIP and WIC, extending Medicaid benefits to more children, and compensating health care practitioners for working with Medicaid recipients. In addition, society must think more maternally and increase health and dental care accessibility, particularly to the poor in rural areas. The article concludes with the thought that if society expects mothers to care for their children, then society must care for mothers.

Evidence against oxidative stress as mechanism of endothelial dysfunction in methionine loading model

Endothelial dysfunction reflects reduced nitric oxide (NO) bioavailability due to either reduced production, inactivation of NO, or reduced smooth muscle responsiveness. Oral methionine loading causes acute endothelial dysfunction in healthy subjects and provides a model in which to study mechanisms. Endothelial function was assessed using flow-mediated dilatation (FMD) of the brachial artery in humans. Three markers of oxidative stress were measured ex vivo in venous blood. NO responsiveness was assessed in vascular smooth muscle and platelets. Oral methionine loading induced endothelial dysfunction (FMD decreased from 2.8 +/- 0.8 to 0.3 +/- 0.3% with methionine and from 2.8 +/- 0.8 to 1.3 +/- 0.3% with placebo; P < 0.05). No significant changes in measures of plasma oxidative stress or in vascular or platelet sensitivity to submaximal doses of NO donors were detected. These data suggest that oxidative stress is not the mechanism of endothelial dysfunction after oral methionine loading. Furthermore, the preservation of vascular and platelet NO sensitivity makes a signal transduction abnormality unlikely.

Unmodified supported thiol/lipid bilayers: studies of structural disorder and conducting mechanism by cyclic voltammetry and AC impedance

Supported thiol/lipid bilayer assembly, one of the most spectacular bilayer systems in recent years, has provided a good model to study biomembranes because of its high mechanical stability. In this work, the structural and conducting property of unmodified Au supported octadecanethiol/phosphatidylcholine bilayers were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The forming process of bilayer was monitored by capacitance plane plot. The normalized membrane capacitance of supported bilayer is 0.52 microF cm(-2). Kinetically controlled voltammograms determined by Butler-Volmer equation were obtained for both thiol monolayer and thiol/lipid bilayer in linear sweep voltammetry. Results of EIS experiment indicate that collapsed sites and pinhole defects exist in thiol monolayer and lipid monolayer, respectively. The difference between the values of experimental and theoretical standard electron transfer rate constant indicates that the conducting mechanism of Au supported thiol monolayer is electron tunneling at collapsed sites. The conducting mechanism of Au supported thiol/lipid bilayer is attributed as the following: the electroactive species could diffuse through pinholes in the lipid monolayer and reach collapsed sites in thiol monolayer, where electron transfer occurs via a tunneling process. The fractional coverage of the lipid monolayer measure by EIS experiments is about 0.98 or higher.

Rotation of NMR images using the 2D chirp-z transform

A quick and accurate way to rotate and shift nuclear magnetic resonance (NMR) images using the two-dimensional chirp-z transform is presented. When the desired image grid is rotated and shifted from the original grid due to patient motion, the chirp-z transform can reconstruct NMR images directly onto the ultimate grid instead of reconstructing onto the original grid and then applying interpolation to get the final real-space image in the conventional way. The rotation angle and shift distances are embedded in the parameters of the chirp-z transform. The chirp-z transform implements discrete sinc interpolation to get values at grid points that are not exactly on the original grid when applying the inverse Fourier transform. Therefore, the chirp-z transform is more accurate than methods such as linear or bicubic interpolation and is more efficient than direct implementation of sinc interpolation because the sinc interpolation is implemented at the same time as reconstruction from k-space.

Electron transfer between ferrocene-modified Au/octadecanethiol/lipid BLM electrode and redox couples in solution

Bilayers incorporated with ferrocene consisting of self-assembled octadecanethiol and lipid monolayer on gold substrates were fabricated. Its electrochemical behaviors in solutions containing different redox couples were investigated by cyclic voltammetry and ac impedance. The transmembrane electron transfer reaction across octadecanethiol self-assembled film and an adsorbed phospholipid layer mediated by ferrocene have been observed in the solution of Fe(CN)6(3-/4-). The formal potential difference between mediator in bilayer lipid membrane (BLM) and redox couple in solution has a great impact on the transmembrane electron transfer behavior. The ferrocene-modified BLM electrodes might be useful for constructing a bilayer-based electrochemical current rectifying device.

Two- and three-dimensional image rotation using the FFT

Techniques for rotating two- and three-dimensional (2-D and 3-D) images using fast Fourier transforms (FFT's) are presented. The methods are applications of the multidimensional chirp algorithm. In the 2-D case, one chirp transformation is sufficient, requiring four 2-D FFT's, In the 3-D case, two successive chirp transformations are required, needing six 3-D FFT's.

The ethics of care: a feminist virtue ethics of care for healthcare practitioners

In this paper I seek to distinguish a feminist virtue ethics of care from (1) justice ethics, (2) narrative ethics, (3) care ethics and (4) virtue ethics. I also connect this contemporary discussion of what makes a virtue ethics of care feminist to eighteenth and nineteenth century debates about male, female, and human virtue. In conclude that by focusing on issues related to gender--primarily those related to the systems, structures, and ideologies that create and sustain patterns of male domination and female subordination--we can begin to appreciate that true care and bona-fide virtue can flourish only in societies that treat all persons with equal respect and consideration.

Towards a just, courageous, and honest resolution of the futility debate

This essay discusses the history of the "futility debate" and the motives that sometimes prompt health care professionals, health care providers, patients, and surrogates to take different sides in it. Changes in the health care system, financial responsibility shifts, technical medical advances, and medical care rationing are analyzed as contributors to the futility debate. So too are variations in the definition of futility examined as part of the current controversy. The respective attitudes of professionals, providers, patients, and surrogates in accepting the goals, capabilities, and limits of medicine are also explored. In particular, the lack of honest communication between health care professionals/health care providers on the one hand and patients/surrogates on the other is acknowledged as a major roadblock in the building of care-focused futility policies. Finally, various initial attempts of hospitals to create futility guidelines are evaluated in order to detect problem areas and to suggest lines of improvement.

Blessed are the peacemakers: commentary on making peace in gestational conflicts

The purpose of this commentary on James Nelson's article [1] is to advocate introducing the ethics of care into the arena of gestational conflict. Too often the debate gets stalled in a maternal versus fetal rights headlock. Interventionists stress fetal over maternal rights: they believe education, post-birth prosecution or pre-birth seizure of pregnant women may be permissible. In contrast to interventionists, other philosophers stress that favoring fetal rights treats women like 'fetal containers'. I question whether we should really consider issues of moral/parental obligations to children in terms of rights. Rather, the language of care should guide moral conduct vis-a-vis children/fetuses. The particularity of each woman's story--the particulars of her human relationships--inform her story. An individual's ability to care is largely a function of whether community cares for her. We must care for others to enable them to care for themselves and their loved ones--born or unborn.

The epistemology and ethics of consensus: uses and misuses of 'ethical' expertise

In this paper I examine the epistemology and ethics of consensus, focusing on the ways in which decision makers use/misuse ethical expertise. The major questions I raise and tentative answers I give are the following: First, are the 'experts' really experts? My tentative answer is that they are bona fide experts who often represent specific interest groups. Second, is the experts' authority merely epistemological or is it also ethical? My tentative answer is that the experts' authority consists not only in their command over specific matters of fact and/or value, but also in their ability to achieve 'consensus' about what is 'true'/'false', or 'right'/'wrong'. Third, should the authority of expertise be limited? My tentative answer is that it should be limited in the area of facts but especially in the area of values. Persons who are ethics 'experts' must be particularly careful to practice an ethics of persuasion rather than an ethics of compulsion. Their role is not to force their group consensus upon decision makers' individual moral perceptions and deliberations; rather it is to help decision makers come to their own conclusions about what they ought to do.