1,457 research outputs found

    Metal-organic framework composites with luminescent gold(III) complexes. Strongly emissive and long-lived excited states in open air and photo-catalysis

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    The encapsulation of luminescent gold(III) complexes by metal–organic frameworks (MOFs) lays the groundwork for new phosphorescent materials with activities that are not readily achieved by the host MOF materials or gold(III) complexes alone. In this work, strong phosphorescence with lifetimes of up to ∼50 μs in open air at room temperature has been achieved by incorporation of cationic cyclometalated gold(III) complexes into MOFs with anionic frameworks to form AuIII@MOFs. The AuIII@MOFs display solid state two-photon-induced phosphorescence. Photo-reduction of methyl viologen to the reduced radical was achieved inside AuIII@MOFs and in the presence of Et3N upon excitation at λ > 370 nm under ambient conditions. These AuIII@MOFs comprise a class of reusable and size-selective heterogeneous photo-catalysts for the aerobic oxidation of secondary amines to imines as well as five other reactions, including oxidative C–H functionalization under aerobic conditions.published_or_final_versio

    Sweet's syndrome in a patient with Crohn's disease: a case report

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    <p>Abstract</p> <p>Background</p> <p>Sweet's syndrome, also known as acute febrile neutrophilic dermatosis, has been associated with malignancy, autoimmune disease and collagen vascular disease. The association of Crohn's disease and Sweet's syndrome is rare. We report a case of Sweet's syndrome in a patient with Crohn's disease.</p> <p>Case presentation</p> <p>A 63-year-old man with a history of Crohn's disease presented with one-week duration of abdominal pain, diarrhea and hematochezia. He also noticed eruption of painful skin rashes all over his body at the same time. Colonoscopy and esophagogastroduodenoscopy (EGD) showed inflammation involving different parts of the gastrointestinal tract consistent with Crohn's disease. Punch biopsy of the skin lesion was consistent with Sweet's syndrome, which has a rare association with Crohn's disease.</p> <p>Conclusion</p> <p>Crohn's disease should be excluded in patients presenting with Sweet's syndrome and diarrhea. Alternatively, Sweet's syndrome should be considered as a diagnosis when a patient with Crohn's disease develops skin lesions.</p

    Topological orbital ladders

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    We unveil a topological phase of interacting fermions on a two-leg ladder of unequal parity orbitals, derived from the experimentally realized double-well lattices by dimension reduction. Z2Z_2 topological invariant originates simply from the staggered phases of spsp-orbital quantum tunneling, requiring none of the previously known mechanisms such as spin-orbit coupling or artificial gauge field. Another unique feature is that upon crossing over to two dimensions with coupled ladders, the edge modes from each ladder form a parity-protected flat band at zero energy, opening the route to strongly correlated states controlled by interactions. Experimental signatures are found in density correlations and phase transitions to trivial band and Mott insulators.Comment: 12 pages, 5 figures, Revised title, abstract, and the discussion on Majorana numbe

    Anyons in a weakly interacting system

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    We describe a theoretical proposal for a system whose excitations are anyons with the exchange phase pi/4 and charge -e/2, but, remarkably, can be built by filling a set of single-particle states of essentially noninteracting electrons. The system consists of an artificially structured type-II superconducting film adjacent to a 2D electron gas in the integer quantum Hall regime with unit filling fraction. The proposal rests on the observation that a vacancy in an otherwise periodic vortex lattice in the superconductor creates a bound state in the 2DEG with total charge -e/2. A composite of this fractionally charged hole and the missing flux due to the vacancy behaves as an anyon. The proposed setup allows for manipulation of these anyons and could prove useful in various schemes for fault-tolerant topological quantum computation.Comment: 7 pages with 3 figures. For related work and info visit http://www.physics.ubc.ca/~fran

    Pyoderma gangrenosum after totally implanted central venous access device insertion

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    <p>Abstract</p> <p>Background</p> <p>Pyoderma gangrenosum is an aseptic skin disease. The ulcerative form of pyoderma gangrenosum is characterized by a rapidly progressing painful irregular and undermined bordered necrotic ulcer. The aetiology of pyoderma gangrenosum remains unclear. In about 70% of cases, it is associated with a systemic disorder, most often inflammatory bowel disease, haematological disease or arthritis. In 25–50% of cases, a triggering factor such as recent surgery or trauma is identified. Treatment consists of local and systemic approaches. Systemic steroids are generally used first. If the lesions are refractory, steroids are combined with other immunosuppressive therapy or to antimicrobial agents.</p> <p>Case presentation</p> <p>A 90 years old patient with myelodysplastic syndrome, seeking regular transfusions required totally implanted central venous access device (Port-a-Cath<sup>®</sup>) insertion. Fever and inflammatory skin reaction at the site of insertion developed on the seventh post-operative day, requiring the device's explanation. A rapid progression of the skin lesions evolved into a circular skin necrosis. Intravenous steroid treatment stopped the necrosis' progression.</p> <p>Conclusion</p> <p>Early diagnosis remains the most important step to the successful treatment of pyoderma gangrenosum.</p

    Transurethral resection of the prostate in Northern Nigeria, problems and prospects

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    <p>Abstract</p> <p>Background</p> <p>Benign prostatic hyperplasia (BPH) is the commonest disease of the urinary tract afflicting the ageing male and is the commonest neoplastic disease in men aged 50 years and above.</p> <p>Transurethral prostatectomy (TURP) is the ultimate treatment of choice for benign prostatic hyperplasia (BPH) due mainly to the preference of minimally invasive surgery, long term relief of symptoms and cost effectiveness. It is however not available to the majority of Nigerians in need of prostatic surgery in Public Health Institutions.</p> <p>Methods</p> <p>The records of patients who underwent prostatectomy in Aminu Kano Teaching Hospital, over the period June 2001 to July 2007 were examined. The bio data of patients and laboratory investigations performed were retrieved.</p> <p>Results</p> <p>Five Hundred and forty two patients were operated upon, out of which 40 were excluded due to open prostatectomy (22 patients), bladder neck stenosis (16 patients) or bladder tumour around the trigon (2 patients). The age range of the patients was 47–110 years with a mean of 67.2 years. 289 patients (80.1%) had urethral catheter in situ at presentation and 11 (3%) patients had suprapubic cystostomy of which only 3 (0.85%) had combined urethral stricture and BPH.</p> <p>Only 131 (26%) had their PSA measured which ranged from 2–100 ng/ml out of which 39(29.8% n = 131) patients had more than 4 ng/ml and cancer of the prostate and 1(0.8%, n = 131) patient had a PSA level of 4 ng/ml and malignant prostate.</p> <p>Hospital stay was 1–32 days (mean 7.9) and the mean follow up period was 5.6 months (range 0–60) and there were 17.5% complications comprising of urinary tract infection (UTI) 7.2%, Orchitis 2.2%, urinary incontinence 0.6%, atonic bladder 1%, erectile dysfunction 0.6%, cerebrovascular accident 0.4%, myocardial infarction 0.4%, deep vein thrombosis 0.4% and disseminated intravascular coagulopathy (DIC) 0.6% and 1.2% mortality. The cost of treatment inclusive of pre-admission investigations was US615.00(rangeUS 615.00 (range US 300–1,300)</p> <p>Conclusion</p> <p>Despite advances in minimally invasive therapy for LUTH/BPH, TURP is the optimum treatment of choice for the ageing male of sub-Saharan Africa. It is however not available to the majority of patients in this region due to poor health allocation and inadequate facilities and training.</p

    Regulation of neutrophil senescence by microRNAs

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    Neutrophils are rapidly recruited to sites of tissue injury or infection, where they protect against invading pathogens. Neutrophil functions are limited by a process of neutrophil senescence, which renders the cells unable to respond to chemoattractants, carry out respiratory burst, or degranulate. In parallel, aged neutrophils also undergo spontaneous apoptosis, which can be delayed by factors such as GMCSF. This is then followed by their subsequent removal by phagocytic cells such as macrophages, thereby preventing unwanted inflammation and tissue damage. Neutrophils translate mRNA to make new proteins that are important in maintaining functional longevity. We therefore hypothesised that neutrophil functions and lifespan might be regulated by microRNAs expressed within human neutrophils. Total RNA from highly purified neutrophils was prepared and subjected to microarray analysis using the Agilent human miRNA microarray V3. We found human neutrophils expressed a selected repertoire of 148 microRNAs and that 6 of these were significantly upregulated after a period of 4 hours in culture, at a time when the contribution of apoptosis is negligible. A list of predicted targets for these 6 microRNAs was generated from http://mirecords.biolead.org and compared to mRNA species downregulated over time, revealing 83 genes targeted by at least 2 out of the 6 regulated microRNAs. Pathway analysis of genes containing binding sites for these microRNAs identified the following pathways: chemokine and cytokine signalling, Ras pathway, and regulation of the actin cytoskeleton. Our data suggest that microRNAs may play a role in the regulation of neutrophil senescence and further suggest that manipulation of microRNAs might represent an area of future therapeutic interest for the treatment of inflammatory disease

    Evaluating the use of the Child and Adolescent Intellectual Disability Screening Questionnaire (CAIDS-Q) to estimate IQ in children with low intellectual ability

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    In situations where completing a full intellectual assessment is not possible or desirable the clinician or researcher may require an alternative means of accurately estimating intellectual functioning. There has been limited research in the use of proxy IQ measures in children with an intellectual disability or low IQ. The present study aimed to provide a means of converting total scores from a screening tool (the Child and Adolescent Intellectual Disability Screening Questionnaire: CAIDS-Q) to an estimated IQ. A series of linear regression analyses were conducted on data from 428 children and young people referred to clinical services, where FSIQ was predicted from CAIDS-Q total scores. Analyses were conducted for three age groups between ages 6 and 18 years. The study presents a conversion table for converting CAIDS-Q total scores to estimates of FSIQ, with corresponding 95% prediction intervals to allow the clinician or researcher to estimate FSIQ scores from CAIDS-Q total scores. It is emphasised that, while this conversion may offer a quick means of estimating intellectual functioning in children with a below average IQ, it should be used with caution, especially in children aged between 6 and 8 years old
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