Magnetic field enhanced nano-tip fabrication for four-probe STM studies

We present an improved method for fabricating tungsten STM tips for measuring nanoscale objects using a multiprobe STM. The tips were prepared by a 'drop-off' technique combined with a magnetic field. For magnetic field strengths above 150?Oe the electrolyte was seen to rotate about the tungsten anode. This rotation reduced the adhesion of bubbles and led to a reduction in the cone angle of the tips produced. This property is advantageous for multiprobe measurements as it allows one to bring multiple tips into close proximity.     

Reexpansion pulmonary edema occurring after thoracoscopic drainage of a pleural effusion

Video assisted thoracoscopic drainage and tale pleurodesis was used to treat a recurrent pleural effusion in a 60 year-old woman undergoing major gynecologic surgery. She developed reexpansion pulmonary edema immediately following surgery. Several important risk factors that were present in this patient are discussed. In addition to almost, complete collapse of the underlying lung for several weeks, thoracoscopy resulted in manipulations and rapid re-inflation of the underlying lung, which further increased the risk to the patient.     

Current concepts in milieu treatment of seriously disturbed children and adolescents.

In a variety of treatment settings, a therapeutic milieu provides intensive psychotherapeutic and psychoeducational experiences for disturbed children and young adolescents. It is generally agreed that effective psychosocial treatment requires a developmentally based treatment approach, collaborative parental involvement, and provision for ongoing staff support and training. In such settings, the treatment plan for each child reflects developmental, psychosocial, biological, cognitive, and neurointegrative aspects of the child's problems and identifies specific roles for psychotherapists, caseworkers, educators, occupational and recreational therapists, and parents (Alt, 1961; Pfeffer, 1979; Redl, 1959; Trieschman, 1969). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perfluoroalkylene-linked aromatic polymers

Polymers of the type (m-C₆H₄·(CF₂)_m·m-C₆H₄-X))n have been synthesised and their properties are reported. They include polyesters and polycarbonates, polysiloxanes, polyimides and poly-(1,3-phenylenehexafluoro-trimethylene. Preparation of the precursors was facilitated by the discovery of a direct fluoroalkylation process involving fluoroalkylcopper intermediates. In various instances, the effects of introducing m-phenylene-perfluoroalkylene units on the properties of these polymers, particularly their glass transition temperatures, are compared with the corresponding effects from m-phenylene ether units.     

One‐Step Preparation of Biocompatible Gold Nanoplates with Controlled Thickness and Adjustable Optical Properties for Plasmon‐Based Applications

The ability to synthesize plasmonic nanomaterials with well‐defined structures and tailorable size is crucial for exploring their potential applications. Gold nanoplates (AuNPLs) exhibit appealing structural and optical properties, yet their applications are limited by difficulties in thickness control. Other challenges include a narrow range of tunability in size and surface plasmon resonance, combined with a synthesis conventionally involving cytotoxic cetyltrimethylammonium (CTA) halide surfactant. Here, a one‐step, high‐yield synthesis of single‐crystalline AuNPLs is developed, based on the combined use of two structure‐directing agents, methyl orange and FeBr₃, which undergo preferential adsorption onto different crystalline facets of gold. The obtained AuNPLs feature high shape homogeneity that enables mesoscopic self‐assembly, broad‐range tunability of dimensions (controlled thickness from ≈7 to ≈20 nm, accompanied by modulation of the edge length from ≈150 nm to ≈2 µm) and plasmonic properties. These merits, coupled with a preparation free of CTA‐halide surfactants, have facilitated the exploration of various uses, especially in bio‐related areas. For example, they are demonstrated as biocompatible photothermal agents for cell ablation in NIR I and NIR II windows. This work paves the way to the innovative fabrication of anisotropic plasmonic nanomaterials with desired attributes for wide‐ranging practical applications.     

Cytokine control in human endometrium

Cytokines within endometrium participate in both menstruation and implantation but also contribute to the defence mechanisms of the mucosal epithelium. Endometrium is under the control of steroid hormones, particularly progesterone and, thus, control of cytokines by this steroid is important. Although appreciable numbers of progesterone receptors are not found in endometrial leucocytes, progesterone can modulate cytokines by acting on uterine cells expressing the receptor. The NFkappaB pathway is important in the control of cytokine synthesis and can modulate production of chemokines, matrix metalloproteinases and the inducible prostaglandin synthesis enzyme COX-2. NFkappaB activity can be inhibited by progesterone by either stimulating synthesis of IkappaB, the molecule that restrains NFkappaB in the cytosol, or after binding to the nuclear receptor, competing with NFkappaB for recognition sites on the relevant gene. In this way, progesterone can limit pro-inflammatory pathways. The major palliatives for endometrial dysfunctions such as menorrhagia and dysmenorrhoea have been the non-steroidal anti-inflammatory drugs that inhibit prostaglandin synthesis. Prostaglandins have major effects on cytokine production but the direct action of prostaglandin E on leucocytes is not a pro-inflammatory response but is to stimulate interleukin 10 and inhibit interleukin 12 synthesis. The likely effect of the non-steroidal anti-inflammatory drugs is on the cells surrounding the small blood vessels, where a synergistic action between prostaglandin and chemokine will induce leucocyte entry and activation leading to lysis of connective tissue and menstruation. At the time of implantation, tight control of cytokine synthesis is required. Although leukaemia inhibitory factor is essential to implantation, the mouse knockout models show that the prostaglandin system is also essential but that there are mutually supportive pathways that compensate for the knockout of many cytokines.     

A cell-free system to study regulation of focal adhesions and of the connected actin cytoskeleton

Assembly and modulation of focal adhesions during dynamic adhesive processes are poorly understood. We describe here the use of ventral plasma membranes from adherent fibroblasts to explore mechanisms regulating integrin distribution and function in a system that preserves the integration of these receptors into the plasma membrane. We find that partial disruption of the cellular organization responsible for the maintenance of organized adhesive sites allows modulation of integrin distribution by divalent cations. High Ca2+ concentrations induce quasi-reversible diffusion of beta1 integrins out of focal adhesions, whereas low Ca2+ concentrations induce irreversible recruitment of beta1 receptors along extracellular matrix fibrils, as shown by immunofluorescence and electron microscopy. Both effects are independent from the presence of actin stress fibers in this system. Experiments with cells expressing truncated beta1 receptors show that the cytoplasmic portion of beta1 is required for low Ca2+-induced recruitment of the receptors to matrix fibrils. Analysis with function-modulating antibodies indicates that divalent cation-mediated receptor distribution within the membrane correlates with changes in the functional state of the receptors. Moreover, reconstitution experiments show that purified alpha-actinin colocalizes and redistributes with beta1 receptors on ventral plasma membranes depleted of actin, implicating binding of alpha-actinin to the receptors. Finally, we found that recruitment of exogenous actin is specifically restricted to focal adhesions under conditions in which new actin polymerization is inhibited. Our data show that the described system can be exploited to investigate the mechanisms of integrin function in an experimental setup that permits receptor redistribution. The possibility to uncouple, under cell-free conditions, events involved in focal adhesion and actin cytoskeleton assembly should facilitate the comprehension of the underlying molecular mechanisms.