Selecting Double Bond Positions with a Single Cation-Responsive Iridium Olefin Isomerization Catalyst.

The catalytic transposition of double bonds holds promise as an ideal route to alkenes of value as fragrances, commodity chemicals, and pharmaceuticals; yet, selective access to specific isomers is a challenge, normally requiring independent development of different catalysts for different products. In this work, a single cation-responsive iridium catalyst selectively produces either of two different internal alkene isomers. In the absence of salts, a single positional isomerization of 1-butene derivatives furnishes 2-alkenes with exceptional regioselectivity and stereoselectivity. The same catalyst, in the presence of Na+, mediates two positional isomerizations to produce 3-alkenes. The synthesis of new iridium pincer-crown ether catalysts based on an aza-18-crown-6 ether proved instrumental in achieving cation-controlled selectivity. Experimental and computational studies guided the development of a mechanistic model that explains the observed selectivity for various functionalized 1-butenes, providing insight into strategies for catalyst development based on noncovalent modifications.

International Collaboration in the Time of COVID-19: The World Hospice and Palliative Care Social Work Network.

In the context of widespread loss, isolation, and grief due to COVID-19, palliative social workers came together in the fall of 2020 to form an international group named the World Hospice and Palliative Care Social Work Network (WHPCSW). This emerging global network is committed to amplifying the innovative work, nuanced skills, research, and education and training provided by palliative social workers across different settings around the world. This article highlights some of the novel interventions developed by social workers in response to the pandemic and describes this coalescing WHPCSW network along with information about its mission and membership.

Reporting radiographers within the European Federation of Radiographer Society (EFRS) member countries - motivation for becoming a reporting radiographer.

INTRODUCTION: Radiographer-led reporting originated in the United Kingdom as a strategy to reduce reporting backlog and time taken to report images. The effectiveness of reporting radiographers has been demonstrated, but their motivational factors have not been thoroughly explored. This survey aims to understand the incentives for radiographers to pursue postgraduate education in reporting radiography across Europe. METHODS: An online survey was conducted, collecting data across a range of topics such as demographic information, professional role, and job satisfaction. Questions assessing the influence of motivational factors on the decision to become a reporting radiographer are presented in this study. Descriptive statistics characterized the respondents' demographics. The motivational aspects were analysed quantitatively by regression analyses. Thematic analyses were performed for the free text responses on motivational aspects. RESULTS: 239 respondents from the UK, Denmark, Norway, Sweden, The Netherlands, Ireland, and Malta completed the survey's motivation section. Increased knowledge and new challenges were the most motivating factors for becoming a reporting radiographer, while less exposure to radiation and less patient contact were the least motivating factors. Job satisfaction was a significant motivator. Gender significantly correlated with the importance of social connections for female reporting radiographers. A cross-country comparison showed that title and position and job security were more important for reporting radiographers from the UK. CONCLUSION: Taking in consideration that a sample of 239 is not generalisable for the role, this survey does provides insights into the motivation behind being a reporting radiographer in Europe. Factors such as increased knowledge, new challenges, and job satisfaction play significant roles. Hindrances experienced by reporting radiographers included lack of time, support, and standards, while aspirations for further professional development were expressed. IMPLICATIONS FOR PRACTICE: A thorough understanding of the motivation behind pursuing postgraduate studies in reporting radiography is a valuable tool for managers, aiding in fostering a positive work environment and attracting/keeping qualified personnel. The findings of this study can be employed in the development of strategies to support and enhance the practice of reporting radiographers.

Experimental realization of Josephson junctions for an atom SQUID.

We report the creation of a pair of Josephson junctions on a toroidal dilute gas Bose-Einstein condensate (BEC), a configuration that is the cold atom analog of the well-known dc superconducting quantum interference device (SQUID). We observe Josephson effects, measure the critical current of the junctions, and find dynamic behavior that is in good agreement with the simple Josephson equations for a tunnel junction with the ideal sinusoidal current-phase relation expected for the parameters of the experiment. The junctions and toroidal trap are created with the painted potential, a time-averaged optical dipole potential technique which will allow scaling to more complex BEC circuit geometries than the single atom-SQUID case reported here. Since rotation plays the same role in the atom SQUID as magnetic field does in the dc SQUID magnetometer, the device has potential as a compact rotation sensor.

Accessing three oxidation states of cobalt in M6L3 nanoprisms with cobalt-porphyrin walls.

Nanocages with porphyrin walls are common, but studies of such structures hosting redox-active metals are rare. Pt2+-linked M6L3 nanoprisms with cobalt-porphyrin walls were prepared and their redox properties were evaluated electrochemically and chemically, leading to the first time that cobalt-porphyrin nanocages have been characterized in CoI, CoII, and CoIII states.

Trypanothione: a novel bis(glutathionyl)spermidine cofactor for glutathione reductase in trypanosomatids.

Glutathione reductase from trypanosomes and leishmanias, unlike glutathione reductase from other organisms, requires an unusual low molecular weight cofactor for activity. The cofactor was purified from the insect trypanosomatid Crithidia fasciculata and identified as a novel glutathione-spermidine conjugate, N1,N8-bis(L-gamma-glutamyl-L-hemicystinyl-glycyl)spermidine, for which the trivial name trypanothione is proposed. This discovery may open a new chemotherapeutic approach to trypanosomiasis and leishmaniasis.

Apolipoprotein E and lipoprotein lipase gene polymorphisms interaction on the atherogenic combined expression of hypertriglyceridemia and hyperapobetalipoproteinemia phenotypes.

The combination of hypertriglyceridemia (hyperTG) and hyperapobetalipoproteinemia (hyperapoB) is associated with an increased coronary artery disease (CAD) risk. Apolipoprotein (apo) E and lipoprotein lipase (LPL) genes are involved in the catabolism of triglycerides (TG)-rich apoB-containing lipoproteins (VLDL). Several apoE and LPL gene variants affecting CAD risk, plasma TG or apoB concentrations have an allelic frequency of >5% in the general population. This study examined the combined effect of frequent apoE and LPL gene polymorphisms on the expression of hyperTG and hyperapoB. ApoE (E2, E3, and E4) and LPL (D9N, N291S, G188E, and P207L) were genotyped and fasting lipid profiles were assessed among 1,441 French-Canadian subjects. Multivariate analyses were performed to estimate the relationship between apoE and LPL gene variants and the risk of hyperTG (TG>1.7 mmol/l) and hyperapoB (apoB>0.9 g/l). Compared to apoE3 carriers, the apoE4 allele significantly increased the risk of expressing the "hyperTG/hyperapoB" phenotype [odds ratio (OR)=1.95; p=0.014]. This risk was significantly exacerbated (OR=4.69; p=0.017) by the presence of frequent deleterious LPL gene variants in this population. The apoE2 allele was negatively associated with hyperTG/hyperapoB (OR=0.49; p=0.002) in the absence of a deleterious LPL gene variant. These results suggest that epistasis is a phenomenon to consider while assessing the CAD risk associated with gene variants or the effect of frequent alleles on high-risk lipid profiles.

Comparison of antitumor activities of pancreatic ribonuclease and its cross-linked dimer.

The cross-linked dimer of bovine pancreatic RNase (M.W. 28,000) is significantly more effective than the monomer in inhibiting tumor development in mice when administered i.p. 1 day after inoculation with sarcoma 180J ascites cells. Animals bearing solid tumors were not affected. In AKR/J mice with advanced leukemia, a single i.p. injection of 100 mug of the dimer led to about 50% reduction in the enlarged lymph nodes and the spleen at 24 hr. The half-life of the dimer in the bloodstream has been determined to be 10 min in rats and 6 min in mice, compared to values of 5 and 3.5 min, respectively, for the monomer. Analyses of the tissues of untreated leukemic mice for RNase and RNase inhibitors show that the tumor tissues are not deficient in RNase activity. Considerations of possible mechanisms of action of the dimer indicate that other basic proteins in this size range may merit examination as cytostatic agents toward transformed cells.

Effects of chronic infection with Trichostrongylus vitrinus and immune suppression with corticosteroid on parasitological, immune and performance variables in crossbred meat lambs.

The effects of, and interactions between chronic Trichostrongylus vitrinus infection and immune suppression with methylprednisolone were investigated for a period of 112 days in a grazed flock of 176 crossbred meat lambs. Worm egg count of non-immune-suppressed lambs increased rapidly from days 21 to 42 post-initial infection, and then steadily declined. Infection was associated with significantly decreased fat depth, eye muscle area and cold carcase weight, and increased circulating anti-T. vitrinus IgG and IgA. Immune suppression led to sustained increases in WEC, and significantly greater worm count, liver weight, fat depth and carcase dressing percentage, and significantly reduced IgG and IgA anti-T. vitrinus titres, lymphocyte counts, adrenal weight, eye muscle area and cold carcase weight. Both infection and immune suppression were associated with significant body weight reductions. Only 39% of reduced growth rate due to infection was attributable to the host immune response to T. vitrinus.

Use of developmental temperature and gastrointestinal tract location to isolate pure Trichostrongylus vitrinus from mixed, naturally acquired trichostrongylid infections in sheep.

OBJECTIVE: To isolate Trichostrongylus vitrinus from naturally-acquired mixed trichostrongylid infections (predominantly Trichostrongylus spp. and Teladorsagia circumcincta) in sheep using differential larval development temperatures and the anatomical location of adults. METHODS: Faeces were collected from ewes with mixed, naturally acquired trichostrongylid infection, and incubated at low temperatures (4°C or 8°C) for 20-68 days depending on temperature. Harvested infective larvae were passaged through worm-free lambs, from which the first 5 m of small intestine was collected and adult worms recovered. Purity of infection with T. vitrinus was assessed by examination of spicules on 100 adult male worms. Eggs of recovered adult female worms were cultured at 25°C and harvested larvae were re-passaged through worm-free lambs. RESULTS: Low temperature incubation (≤8°C) successfully exploited variation in the developmental temperature required by pre-parasitic stages of small intestinal nematodes, allowing T. vitrinus to develop while others did not. Differential organ harvest from infected sheep allowed isolation of T. vitrinus from other gastrointestinal nematodes, with amplification of pure T. vitrinus achieved by passage through a further generation of lambs. CONCLUSION: A successful method for the isolation of pure T. vitrinus from mixed infections is described. The resulting pure strain of T. vitrinus has been amplified and is held by two institutions for use in research (CSIRO reference SARDI 2011 strain).

Do intact viral particles survive excimer laser ablation?

OBJECTIVE: To determine if intact and potentially infectious viral particles can withstand excimer laser ablation and possibly pose a health hazard to medical personnel. METHODS: Excimer laser ablation of fibroblasts infected with attenuated varicella-zoster virus was performed. The laser plume was collected for polymerase chain reaction analysis and viral culture. RESULTS: While viral DNA was detected in the material trapped from the laser plume, live virus could not be demonstrated to have survived ablation. CONCLUSIONS: Attenuated varicella-zoster virus does not seem to survive excimer laser ablation. However, we recommend the use of safety precautions such as wearing a mask during the procedure. Further research is necessary to determine if other viruses could possibly remain infectious despite exposure to excimer laser radiation.

In vitro activity of recombinant lysostaphin-antibiotic combinations toward methicillin-resistant Staphylococcus aureus.

In vitro bactericidal experiments were performed with combinations of recombinant lysostaphin and various antibiotics against five strains of Staphylococcus aureus, including clinical isolates of methicillin-resistant S. aureus (MRSA). Sublethal concentrations of lysostaphin combined with beta-lactam antibiotics (including benzylpenicillin, methicillin, and cephalosporin B), bacitracin, or polymyxin B, exhibited rapid synergistic bactericidal activity against all S. aureus strains tested. Lysostaphin activity was additive when combined with either vancomycin, gentamicin, tetracycline, or erythromycin. Synergistic combinations of recombinant lysostaphin and antibiotics might be applicable to controlling cutaneous staphylococcal infections and MRSA carriage.

Optic disk edema as a presentation of Propionibacterium acnes endophthalmitis.

PURPOSE: To report a patient with an initial presentation of optic disk edema secondary to Propionibacterium acnes endophthalmitis. METHODS: Interventional case report. The patient had surgery and treatment related to endophthalmitis. Nine months after cataract surgery with posterior chamber lens implant, a 79-year-old man receiving topical corticosteroids in the same eye presented with best-corrected visual acuity of 20/60, a superior visual field defect, and optic nerve edema without intraocular inflammation. One year postoperatively, the eye presented a further decrease in best-corrected visual acuity, and a dense white plaque was noted on the posterior capsule. RESULTS: One year postoperatively, a partial capsulectomy with vitrectomy and injection of intravitreal antibiotics was performed. Hematoxylin and eosin stain of the posterior capsule plaque revealed gram-positive coccobacilli characteristic of P. acnes. CONCLUSION: Propionibacterium acnes endophthalmitis may present after cataract surgery with intraocular lens implant with decreased vision, optic disk edema, and a visual field defect.

Urinary amino acid excretion by patients with beta-thalassemia.

Twenty-four hour urinary amino acid excretion has been studied in patients with beta-thalassemia (four adult major, two adult intermedia, and three children major). beta-Aminoisobutyric acid was found to be increased (14-fold on the average) in patients with beta-thalassemia without evidence for increase in the excretion of most other amino acids. No correlation of beta-aminoisobutyric acid excretion with the hematological status of the patient was found. Elevated taurine excretion (2-fold) was also noted in the adult patients with beta-thalassemia. Greatly increased excretion of beta-aminoisobutyric acid appears to correlate with a poor prognosis and may reflect generalized tissue catabolism rather than being a specific indicator of ineffective erythropoiesis.

Respirable particles in the excimer laser plume.

PURPOSE: To determine whether respirable-size particles are present in the excimer laser plume following ablation of the corneal stroma. SETTING: Outpatient laser vision correction facility. METHODS: In this experimental study, an excimer laser was used to ablate 2 eye-bank corneas. Material from the plume was collected with filter paper that was coupled to a smoke evacuator. The filter paper was examined and photographed with an electron microscope. The particle size was measured with a computer program using digitized images of the photographs. As a control, room air was sampled using a smoke evacuator connected to a holder containing filter paper prior to the tissue ablation. RESULTS: Ninety-eight particles were measured. The mean diameter was 0.22 microm +/- 0.056 (SD). No particles were seen on the control filter paper. CONCLUSIONS: The plume created during excimer laser ablation of the cornea contained respirable-size particles. It is not known whether inhalation of these particles poses a significant health hazard. However, we recommend that a mask be worn by the surgeon and technical personnel assisting in excimer laser surgery. The plume should also be evacuated.

Reducing the endoscopic workload: does serological testing for Helicobacter pylori help?

OBJECTIVE: Serological screening for Helicobacter pylori (H. pylori) in young (< or = 45 years) dyspeptic patients has been used to avoid oesophago-gastro-duodenoscopy (OGD). We used serology to identify seronegative and seropositive patients without sinister symptoms and combined approaches of avoiding OGD in both groups. We aimed to determine the reduction of OGD in this group. DESIGN: Prospective study on the treatment of 232 patients with dyspepsia. SETTING: Six hundred and fifty bed district general hospital serving rural Northamptonshire, UK. INTERVENTIONS: Two hundred and thirty-two patients referred by local general practitioners for OGD were offered serology. Symptom severity was scored using a questionnaire. One hundred and eleven seronegative patients received symptomatic treatment, 105 seropositive patients received triple therapy for 1 week. Sixteen patients with equivocal results were offered OGD. Patients were followed up after 6 months. MAIN OUTCOME MEASURES: Severity of dyspepsia symptoms and proportion of patients returning for OGD. RESULTS: Fifteen equivocal patients underwent OGD, one refused. Forty-six patients (33 seronegative, 13 seropositive) had persisting symptoms and underwent OGD. Mean symptom severity was reduced significantly in equivocal (P<0.01), seronegative (P<0.001) and seropositive (P<0.001) patients. Fewer seronegative patients were symptom-free at follow up compared to seropositive patients (n = 15 (16%) vs n = 48 (51%); P<0.001), 171 patients avoided OGD, a 74% reduction. CONCLUSIONS: Use of H. pylori serology in the management of young dyspeptic patients without sinister symptoms can reduce the OGD workload by 74%, decreasing the length of time that older patients, who are at greater risk of malignant disease, may have to wait for OGD.

Longitudinal study of behaviour disorders in low birthweight infants.

AIM: To compare the prevalence of childhood and adolescent behavioural problems in low birthweight infants with matched controls. METHODS: A cohort study of a geographically defined population of survivors of

Effect of changes in graduate medical education funding on emergency medicine residency programs.

OBJECTIVE: To determine whether changes in graduate medical education (GME) funding have had an impact on emergency medicine (EM) residency training programs. METHODS: A 34-question survey was mailed to the program directors (PDs) of all 115 Accreditation Council for Graduate Medical Education (ACGME)-accredited EM residency programs in the United States in the fall of 1998, requesting information concerning the impact of changes in GME funding on various aspects of the EM training. The results were then compared with a similar unpublished survey conducted in the fall of 1996. RESULTS: One hundred one completed surveys were returned (88% response rate). Seventy-one (70%) of the responding EM residency programs were PGY-I through PGY-III, compared with 55 (61%) of the responding programs in 1996. The number of PGY-II through PGY-IV programs decreased from 25 (28%) of responding programs in 1996 to 17 (16%). The number of PGY-I through PGY-IV programs increased slightly (13 vs 10); the number of EM residency positions remained relatively stable. Fifteen programs projected an increase in their number of training positions in the next two years, while only three predicted a decrease. Of the respondents, 56 programs reported reductions in non-EM residency positions and 35 programs reported elimination of fellowship positions at their institutions. Only four of these were EM fellowships. Forty-six respondents reported a reduction in the number of non-EM residents rotating through their EDs, and of these, 11 programs reported this had a moderate to significant effect on their ability to adequately staff the ED with resident physicians. Sixteen programs limited resident recruitment to only those eligible for the full three years of GME funding. Eighty-seven EM programs reported no change in faculty size due to funding issues. Sixty-two programs reported no change in the total number of hours of faculty coverage in the ED, while 34 programs reported an increase. Three EM programs reported recommendations being made to close their residency programs in the near future. CONCLUSIONS: Changes in GME funding have not caused a decrease in the number of existing EM residency and fellowship training positions, but may have had an impact in other areas, including: an increase in the number of EM programs structured in a PGY-I through PGY-III format (with a corresponding decrease in the number of PGY-II through PGY-IV programs); a decrease in the number of non-EM residents rotating through the ED; restriction of resident applicants who are ineligible for full GME funding from consideration by some EM training programs; and an increase in the total number of faculty clinical hours without an increase in faculty size.

The effect of dietary protein on cystine excretion in patients with cystinuria.

Seven patients with homozygous cystinuria were studied on a metabolic ward to determine the effect of dietary manipulation on urinary cystine excretion. Isocaloric diets were calculated based on body weight and activity. Balance studies were performed for 5 days on a low protein diet (9.4 +/- 1.0% total calories) with equal amounts of animal and plant protein sources and an additional 5 days on a high protein (27 +/- 3.0% of total calories) with 70% animal protein. A significant (p less than 0.01) decrease in the excretion of 1/2-cystine, histidine, 3-methylhistidine, 1-methylhistidine, lysine, and ornithine plus arginine occurred on the low protein diet. The mean excretion of 1/2-cystine on the high protein diet was 6.13 +/- 1.48 mMoles per 24 hours which decreased to 4.89 +/- 1.06 mMoles per 24 hours on the low protein diet (p less than 0.001). Thirty seven percent of urine collections during the study were less than 2 liters/24 hours despite the fact that patients were encouraged to drink enough fluid to make 3 liters of urine/24 hours. For patients whose customary diet is high in animal protein, a more vegetarian diet may significantly reduce urinary cystine excretion. Cystine excretion in patients with cystinuria may be significantly different from day to day if animal protein consumption is variable.

Visual diagnosis of hematologic and oncologic diseases.

Cancer-related problems are seen frequently by the emergency physician. More difficult presentations are seen with premonitory symptoms, paraneoplastic syndromes, and nonspecific lesions. Dermatologic paraneoplastic syndromes are numerous, nonspecific, and consist of hamartomatous growths, texture changes, new hair growth, or changes in skin color. Alteration of skin color may be of practically any color, localized or diffuse, and of sudden or indolent onset. Hormone production by tumors may lead to acne, hirsutism, gynecomastia, or a cushingoid appearance. Pruritus may herald the onset of leukemia or lymphoma and be intolerable, as with erythroderma. All suspicious presentations require thorough investigation for underlying disease. Metastasis to skin is not common and implies a poor prognosis if seen. Most metastases are seen on the head and neck, anterior chest wall, and abdomen. Basal cell and squamous cell carcinomas commonly occur in sun-exposed areas. Basal cell is locally destructive, whereas squamous cell occasionally metastasizes to local lymph nodes. Malignant melanoma is the leading fatal illness originating in skin, with a dramatic rise in incidence. It is classically described as asymmetric with irregular borders, is elevated, and shows color variegation; however, melanoma may present atypically, particularly in non-whites. Kaposi's sarcoma lesions are well-demarcated, symmetric, smooth nodules that appear purplish-brown, particularly if below the knee (owing to venous stasis). The closely interrelated structures of the eye and orbit are easily disturbed, leading to the presenting symptoms of visual disturbances, exophthalmos, pain, and ocular motility disorders. Primary tumors are not unusual and may include retinoblastoma, rhabdomyosarcoma, and melanoma. Equally common are metastatic lesions, most commonly lung and breast carcinoma. An estimation of the malignancy of bony lesions can be made by assessing the zone of transition, periosteal reaction, and bone destruction. A malignant lesion will more likely have a broad zone of transition, irregular periosteal reaction, and moth-eaten or permeative destruction of trabeculae. Metastatic bone lesions primarily occur in sites of persistent red marrow: skull, ribs, vertebrae, pelvis, and proximal humerus and femur. Bony lesions can be blastic or lytic in nature. Solitary pulmonary nodules that have not grown for 2 years can be assumed to be benign. Calcification seen on plain films are a strong (but not absolute) indication of benignancy. Lesions that are greater than 3 to 4 cm in diameter, have irregular contours, are cavitated with thick walls, have multiple peripheral nodules, and have lack of calcification are more likely malignant.