A Versatile and Efficient Strategy to Discrete Conjugated Oligomers.

An efficient and scalable strategy to prepare libraries of discrete conjugated oligomers (D = 1.0) using the combination of controlled polymerization and automated flash chromatography is reported. From this two-step process, a series of discrete conjugated materials from dimers to tetradecamers could be isolated in high yield with excellent structural control. Facile and scalable access to monodisperse libraries of different conjugated oligomers opens pathways to designer mixtures with precise composition and monomer sequence, allowing exquisite control over their physical, optical, and electronic properties.

Direct Access to Functional (Meth)acrylate Copolymers through Transesterification with Lithium Alkoxides.

A straightforward and efficient synthetic method that transforms poly(methyl methacrylate) (PMMA) into value-added materials is presented. Specifically, PMMA is modified by transesterification to produce a variety of functional copolymers from a single starting material. Key to the reaction is the use of lithium alkoxides, prepared by treatment of primary alcohols with LDA, to displace the methyl esters. Under optimized conditions, up to 65% functionalization was achieved and copolymers containing alkyl, alkene, alkyne, benzyl, and (poly)ether side groups could be prepared. The versatility of this protocol was further demonstrated through the functionalization of both PMMA homo and block copolymers obtained through either radical polymerization (traditional and controlled) or anionic procedures. The scope of this strategy was illustrated by extension to a range of architectures and polymer backbones.

Dual-pathway chain-end modification of RAFT polymers using visible light and metal-free conditions.

We report a metal-free strategy for the chain-end modification of RAFT polymers utilizing visible light. By turning the light source on or off, the reaction pathway in one pot can be switched between either complete desulfurization (hydrogen chain-end) or simple cleavage (thiol chain-end), respectively. The versatility of this process is exemplified by application to a wide range of polymer backbones under mild, quantitative conditions using commercial reagents.

Effects of Tailored Dispersity on the Self-Assembly of Dimethylsiloxane-Methyl Methacrylate Block Co-Oligomers.

The effect of dispersity on block polymer self-assembly was studied in the monodisperse limit using a combination of synthetic chemistry, matrix-assisted laser desorption ionization spectroscopy, and small-angle X-ray scattering. Oligo(methyl methacrylate) (oligoMMA) and oligo(dimethylsiloxane) (oligoDMS) homopolymers were synthesized by conventional polymerization techniques and purified to generate an array of discrete, semidiscrete, and disperse building blocks. Coupling reactions afforded oligo(DMS-MMA) block polymers with precisely tailored molar mass distributions spanning single molecular systems (D = 1.0) to low-dispersity mixtures (D ≈ 1.05). Discrete materials exhibit a pronounced decrease in domain spacing and sharper scattering reflections relative to disperse analogues. The order-disorder transition temperature (TODT) also decreases with increasing dispersity, suggesting stabilization of the disordered phase, presumably due to the strengthening of composition fluctuations at the low molar masses investigated.

Chemoselective Radical Dehalogenation and C-C Bond Formation on Aryl Halide Substrates Using Organic Photoredox Catalysts.

Despite the number of methods available for dehalogenation and carbon-carbon bond formation using aryl halides, strategies that provide chemoselectivity for systems bearing multiple carbon-halogen bonds are still needed. Herein, we report the ability to tune the reduction potential of metal-free phenothiazine-based photoredox catalysts and demonstrate the application of these catalysts for chemoselective carbon-halogen bond activation to achieve C-C cross-coupling reactions as well as reductive dehalogenations. This procedure works both for conjugated polyhalides as well as unconjugated substrates. We further illustrate the usefulness of this protocol by intramolecular cyclization of a pyrrole substrate, an advanced building block for a family of natural products known to exhibit biological activity.

A Versatile and Scalable Strategy to Discrete Oligomers.

A versatile strategy is reported for the multigram synthesis of discrete oligomers from commercially available monomer families, e.g., acrylates, styrenics, and siloxanes. Central to this strategy is the identification of reproducible procedures for the separation of oligomer mixtures using automated flash chromatography systems with the effectiveness of this approach demonstrated through the multigram preparation of discrete oligomer libraries (D = 1.0). Synthetic availability, coupled with accurate structural control, allows these functional building blocks to be harnessed for both fundamental studies as well as targeted technological applications.

Metal-Free Removal of Polymer Chain Ends Using Light.

A light-mediated method for the facile removal of polymer end groups that are common to controlled radical polymerization techniques is presented. This metal-free strategy is general, being effective for chlorine, bromine, and thiocarbonylthio moieties as well as a number of different polymer families (styrenic, acrylic, and methacrylic). In addition to solution reactions, this process is readily translated to thin films, where light mediation allows the straightforward fabrication of hierarchically patterned polymer brushes.

Simple Benchtop Approach to Polymer Brush Nanostructures Using Visible-Light-Mediated Metal-Free Atom Transfer Radical Polymerization.

The development of an operationally simple, metal-free surface-initiated atom transfer radical polymerization (SI-ATRP) based on visible-light mediation is reported. The facile nature of this process enables the fabrication of well-defined polymer brushes from flat and curved surfaces using a "benchtop" setup that can be easily scaled to four-inch wafers. This circumvents the requirement of stringent air-free environments (i.e., glovebox), and mediation by visible light allows for spatial control on the micron scale, with complex three-dimensional patterns achieved in a single step. This robust approach leads to unprecedented access to brush architectures for nonexperts.

Metal-free atom transfer radical polymerization.

Overcoming the challenge of metal contamination in traditional ATRP systems, a metal-free ATRP process, mediated by light and catalyzed by an organic-based photoredox catalyst, is reported. Polymerization of vinyl monomers are efficiently activated and deactivated with light leading to excellent control over the molecular weight, polydispersity, and chain ends of the resulting polymers. Significantly, block copolymer formation was facile and could be combined with other controlled radical processes leading to structural and synthetic versatility. We believe that these new organic-based photoredox catalysts will enable new applications for controlled radical polymerizations and also be of further value in both small molecule and polymer chemistry.

From distress guidelines to developing models of psychosocial care: current best practices.

Psychological distress has been recognized as having a significant effect upon cognitive and emotional functioning, quality of life, and in some populations increased costs of care. Screening for distress and provision of psychosocial care in oncology treatment settings has been identified as a future accreditation standard by the American College of Surgeons Commission on Cancer (CoC). Because there are few available models of programs of distress screening and referral to inform oncology social workers and other members of the psychosocial support team with planning their own programs, this article seeks to provide exemplars of best practices that are currently in place in four different settings where psychosocial support is provided to people living with cancer and their families. Each program will provide an overview of how it was successfully established and its contribution toward evolving evidence-informed best practices.

One-pot synthesis of polyrotaxanes via acyclic diene metathesis polymerization of supramolecular monomers.

A one-pot synthesis of polyrotaxanes has been developed. The method employs a supramolecular monomer comprising a polymerizable ammonium salt and crown ether, in combination with dynamic ADMet polymerization. Ultimately, highly efficient complexation, polymerization, and end-capping were accomplished in a single operation to yield polyrotaxanes with M(w) up to 19.3 kDa and >80% of the repeat units being complexed.

Providing support at time of death from cancer: results of a 5-year post-bereavement group study.

Despite advances in the quality and availability of hospice and palliative care for people with end stage cancers, research addressing the psychosocial needs of family members and concerned others during the dying process has been limited primarily to caregivers. In addition, many of these studies focused on the recently bereaved. In this study, the authors sought to broaden that perspective by examining the psychosocial needs of secondary survivors, a term that applies to caregivers, family members, and others who felt a caring bond with a dying person. A qualitative exploration of needs expressed by secondary survivors following the conclusion of a structured 8-week psychoeducational grief group experience revealed that secondary cancer survivors experience a sense of isolation and powerlessness that is often unrecognized by physicians, nurses, oncology social workers, or other health care professionals. Furthermore, these secondary survivors needed support that extends well beyond activities that are traditionally associated with the physical and emotional care of the dying. Social work intervention strategies directed toward helping secondary survivors assert personal needs, develop greater proximity with the health care team, and prepare for the processes associated with end-of-life may be helpful later during bereavement.

Screening for psychological and physical distress in a cancer inpatient treatment setting: a pilot study.

OBJECTIVE: Although several large distress studies have been conducted in outpatient oncology treatment settings, there are few, if any, studies that describe the incidence of psychological and physical distress in the inpatient oncology treatment setting. This pilot study hypothesized that inpatients experience levels of psychological distress that are equivalent to or greater than those reported in large outpatient studies. The study also sought to contribute to physical and psychological symptom distress incidence data. METHODS: Using two measures designed to screen for psychological and physical distress, the Brief Symptom Inventory-18 and the M.D. Anderson Symptom Inventory, 52 oncology patients were screened within 24 h of admission to a hospital oncology unit. RESULTS: Nearly two-thirds of the inpatient respondents reported levels of psychological distress that were not only within the clinically significant range but also at a rate that was nearly double that found in the outpatient distress screening studies that have been conducted to date. The physical symptoms most often rated at the severe level included fatigue (34.6%), pain (27.4%), and dry mouth (25.5%). CONCLUSIONS: Failure to screen for psychological and physical symptom distress has lead to under recognition of a population that may have higher levels of distress than their outpatient counterparts and could potentially lead to uneven access to biopsychosocial support. Results support the notion that routinely screening for psychological and physical distress should become a first step in the assessment of the biopsychosocial needs of people receiving inpatient treatment for cancer.

Decreasing psychological distress in cancer inpatients using FLEX Care®: a pilot study.

While the incidence of psychological distress among people receiving treatment for cancer in outpatient treatment settings has received attention by researchers, few studies have investigated the incidence of psychological distress in inpatient settings. Similarly, efficacy or effectiveness studies describing psychosocial interventions with cancer patients in inpatient settings are all but absent from the research literature. The purpose of this study was to screen for psychological distress among persons receiving inpatient treatment for cancer and to then test the efficacy of a communications model known as FLEX Care®, used to enhance routine psychosocial care, in an effort to reduce measurable levels of psychological distress. Following the vetting of more than 400 potential participants, 35 met rigorous screening criteria and also consented to participate in this randomized pre-post control group study. The intervention group received the FLEX Care®-enhanced routine psychosocial intervention, while the control group received the routine psychosocial intervention alone. Mean scores for psychological distress were found to be nearly twice as high in the study sample as those levels reported in outpatient studies. Additionally, participants who received the FLEX Care®-enhanced psychosocial intervention experienced a significant reduction in psychological distress in contrast to participants in the control setting. The findings from this study underscore the need to screen for symptoms of psychological distress in inpatient settings and lend preliminary support to the use of personalized psychosocial intervention strategies that can be used as adjuvant to routine psychosocial care in the inpatient setting to reduce psychological distress.

Synthesis of a molecular charm bracelet via click cyclization and olefin metathesis clipping.

We describe the synthesis of a polycatenated cyclic polymer, a structure that resembles a molecular charm bracelet. Ruthenium-catalyzed ring-opening metathesis polymerization of an amino-containing cyclic olefin monomer in the presence of a chain transfer agent generated an alpha,omega-diazide functionalized polyamine. Cyclization of the resulting linear polyamine using pseudo-high-dilution copper-catalyzed click cyclization produced a cyclic polymer in 19% yield. The click reaction was then further employed to remove linear contaminants from the cyclic polymer using azide- and alkyne-functionalized scavenging resins, and the purified cyclic polymer product was characterized by gel permeation chromatography, (1)H NMR spectroscopy, and IR spectroscopy. Polymer hydrogenation and conversion to the corresponding polyammonium species enabled coordination and interlocking of diolefin polyether fragments around the cyclic polymer backbone using ruthenium-catalyzed ring-closing olefin metathesis to afford a molecular charm bracelet structure. This charm bracelet complex was characterized by (1)H NMR spectroscopy, and the catenated nature of the small rings was confirmed using two-dimensional diffusion-ordered NMR spectroscopy.

The new adult orphan: issues and considerations for health care professionals.

The death of the last parent has a profound effect on survivors. Health care workers are often the first source of anticipatory guidance for newly orphaned adults as they cope with grief, loss, and awareness that their lives are forever changed. It is estimated that more than 80 million Americans were born between 1946 and 1964. As this Baby Boomer generation, often defined as seeing themselves as culturally special, becomes "orphaned," they may be less aware, less prepared, and less supported than any previous group of Americans regarding this life event. For a number of adults, the loss creates many unexpected results that can destabilize life in profound ways. This article describes the unique new realities of helping adult orphans as they relate to health care providers and discusses the problems associated with prolonged and complicated grief. Implications for geriatric caregivers, mental health providers, health educators, and others are proposed.

Switching and extension of a [c2]daisy-chain dimer polymer.

We report the synthesis of a [c2]daisy-chain dimer via ruthenium-catalyzed ring-closing olefin metathesis. Confirmation of the interlocked nature of the structure was achieved through single-crystal X-ray diffraction analysis. The dimer could be readily switched from the bound to the unbound conformation by treatment with 3.0 equiv of KOH and subsequently reprotonated by treatment with 3.0 equiv of HPF(6). Azide functionalization of the dimer enabled incorporation in linear step-growth polymer chains using the alkyne-azide "click" reaction. Gel permeation chromatography coupled with multiangle laser light scattering analysis showed the polymers contained 22 dimers and had a radius of gyration of 14.8 nm. Acylation of the amines of the dimers sterically forced elongation of the interlocked units, and MALLS analysis of the polymer showed a 48% increase in the R(g) (21.4 nm).