3,108 research outputs found
A preliminary assessment of the radiological impact of the Chernobyl reactor accident on the population of the European Community
Access to Medical Dermatologic Care In the United States
Dermatological complaints account for approximately 6% of all outpatient visits. Many dermatologic conditions necessitate timely and quality care to avert morbidity and mortality. Examples of conditions needing early and comprehensive dermatological treatment include melanoma, the 6th leading cause of cancer in the United States, and psoriasis, a significant cause of disability. Dermatologists provide special expertise in the care of patients with skin disorders. Unfortunately, despite projections of an oversupply of specialists, market demands suggest an undersupply as well as a geographic maldistribution of dermatologists in the United States. Access to efficient dermatological care of high quality is an increasingly important and challenging problem. In examining issues of access, it is important to establish some general definitions. According to the American Heritage Dictionary, 4th edition, accessibility is "the quality of being at hand when needed" or "the attribute of being easy to meet or deal with." For the purposes of this paper, access is defined as the ease with which one needing care can utilize existing, appropriate services. In this regard, good access to care means that appropriate services are readily available to the people who need them. Measures of access to care provide an important means for evaluating the quality of existing health care delivery systems and informing sound policy decisions. To date, most research regarding access to dermatologic care has focused on workforce characteristics. Unfortunately, limitations in access to care extend beyond issues like a shortage of health care providers or facilities, as many factors affect access to health care services. These include, but are not limited to, the balance between supply (i.e. the amount of available and appropriate services) and demand (i.e. the number of needed services), as well as the proximity of the supply relative to the demand (e.g. geographic distribution) and the resources required in utilizing the supply (e.g. insurance, money, time, transportation, etc.). Consequently, this paper will analyze the existing data regarding access to medical dermatologic care in the United States; the current measures used for quantifying and projecting supply and demand; and the feasibility of suggested policies for improving access to dermatological services.Master of Public Healt
Two Physical Methods for the Quantitative Determination of One Component of a Mixture of Gases
Chemotherapy versus supportive care in advanced non-small cell lung cancer: improved survival without detriment to quality of life
BACKGROUND: In 1995 a meta-analysis of randomised trials investigating the value of adding chemotherapy to primary treatment for non-small cell lung cancer (NSCLC) suggested a small survival benefit for cisplatin-based chemotherapy in each of the primary treatment settings. However, the metaanalysis included many small trials and trials with differing eligibility criteria and chemotherapy regimens. METHODS: The aim of the Big Lung Trial was to confirm the survival benefits seen in the meta-analysis and to assess quality of life and cost in the supportive care setting. A total of 725 patients were randomised to receive supportive care alone (n = 361) or supportive care plus cisplatin-based chemotherapy (n = 364). RESULTS: 65% of patients allocated chemotherapy (C) received all three cycles of treatment and a further 27% received one or two cycles. 74% of patients allocated no chemotherapy (NoC) received thoracic radiotherapy compared with 47% of the C group. Patients allocated C had a significantly better survival than those allocated NoC: HR 0.77 (95% CI 0.66 to 0.89, p = 0.0006), median survival 8.0 months for the C group v 5.7 months for the NoC group, a difference of 9 weeks. There were 19 (5%) treatment related deaths in the C group. There was no evidence that any subgroup benefited more or less fromchemotherapy. No significant differences were observed between the two groups in terms of the pre-defined primary and secondary quality of life end points, although large negative effects of chemotherapy were ruled out. The regimens used proved to be cost effective, the extra cost of chemotherapy being offset by longer survival. CONCLUSIONS: The survival benefit seen in this trial was entirely consistent with the NSCLC meta-analysis and subsequent similarly designed large trials. The information on quality of life and cost should enablepatients and their clinicians to make more informed treatment choices
The ferroelectric nematic phase: on the role of lateral alkyloxy chains.
The synthesis and characterisation of the 4-({[4â-nitro-(1,1'-biphenyl)â4-yl]oxy}carbonyl)phenyl 2-alkoxy-4-methoxybenzoates are reported: the 1O(m-On)PEPEBNO2 series. These materials include an additional phenyl ring compared to the extensively studied ferroelectric nematogen RM734, added to increase the liquid crystal transition temperatures. All members of the series exhibited both conventional nematic (N) phase and ferroelectric nematic (NF) phases; TNI and TNFN both decrease on increasing n, the length of the lateral alkoxy chain. The properties of this four-ring series are compared with analogous three-ring laterally substituted variants of RM734; the addition of the extra phenyl ring has a significantly more pronounced effect on the value of TNI than on TNFN. The increase in TNI may be attributed to the enhanced structural anisotropy and more favourable intermolecular interactions arising from the insertion of the phenyl ring, whereas the much weaker effect on TNFN may reflect a change in the shape of the molecule. We also report two materials with three-ring structures, the 4'-nitro-(1,1'-biphenyl)-4-yl 2-alkoxy-4-methoxybenzoates: 1O(m-On)PEBNO2 (n=1 and 2). The removal of the ester linkage between RM734 and 1O(m-O1)PEPNO2 extinguishes the NF phase and this appears to be consistent with a model in which the molecules are described in terms of a longitudinal surface charge density wave
Modelling the effects of the anode work function in PPV LED
Transparent conducting oxides are widely used as the transparent electrode in polymer light emitting diodes (PLEDs). The physical properties of these materials and consequently device performance strongly depend on their processing and surface treatment. The injection of charge from the transparent electrode into the polymer layer occurs by tunnelling through a potential barrier from the electrode to molecules close to it. This barrier is influenced by the difference in the relevant energy levels of electrode material and polymer molecules, the external applied potential, the Coulomb potential of the charges present in the polymer layer and the potential of their image charges on the electrodes, and may also be altered by electrode degradation effects. A better understanding of the effect of varying this potential barrier on the functioning of PLED is necessary to achieve further improvements in these applications. Here we present a theoretical study of the influence of changes in the potential barrier at the transparent electrode, on bipolar charge evolution through thin polymer layers, in the absence of defects and impurity states, while the other electrode functions as an ohmic contact. Results of a mesoscopic model provide insight into bipolar charge injection, charge and recombination distribution throughout the polymer layer, and may suggest new materials and processing methods to optimize these optoelectronic devices.FEDER.Fundação para a CiĂȘncia e a Tecnologia (FCT) â Programa Operacional âCiĂȘncia , Tecnologia, Inovaçãoâ â POCTI/CTM/41574/2001, CONC-REEQ/443/EEI/2005; SFRH/BD/22143/2005
High-Tc via electron polar coupling: relation to low-Tc superconductivity and to chiral symmetry in particle physics
Directional coupling of Thornber-Feynman polarization with the high-Tc ARPES
distribution specifies the optimum flatband pseudogap \Delta and mobile
localized quasiparticle. This coupling peaks by tuning the statistics and
interaction energy to produce stable short-ranged directional pairing that
reflects the lattice asymmetry. Analogous energy gap and BCS ratio parameters
are identified for low-Tc long-range acoustical phonons and for
quark-anti-quark tightly bound chiral pions in particle physics.Comment: 25 pages, 4 figures, accepted for publication in Physica
AN ASSESSMENT OF KNOWLEDGE AND ATTITUDES OF GENETIC COUNSELING SERVICES IN U.S. HTCs
Hemophilia is a hereditary bleeding disorder which requires lifelong specialized care. A network of Hemophilia Treatment Centers (HTCs) exists to meet the medical needs of patients affected by hemophilia. Genetic counseling services are an integral part of the HTC model of care; however, many HTCs do not have genetic counselors on staff. As a result, the duty to provide these services must fall to other healthcare providers within the HTC. To assess the knowledge and attitudes of these providers we developed a 49 question survey that was distributed electronically to hematologists and nurses at U.S. HTCs. The survey consisted of a three sections: demographic information, knowledge of hemophilia genetics, and attitudes towards genetic services. A total of 111 complete responses were received and analyzed. The average knowledge score among all participants was 74.8% with a total of 81 participants receiving a passing score of 70% or above. Thirty participants scored below 70% in the knowledge section. In general, attitude scores were high indicating that the majority of hematologists and nurses in HTCs feel confident in their ability to provide genetic counseling services. Over 90% of participants reported that they have some form of access to genetic counseling services at their center.
Hematologists and nurses practicing in U.S. HTCs demonstrate sufficient knowledge of the genetics of hemophilia, and they generally feel confident in their ability to provide genetic counseling services to their patients. While their knowledge is sufficient, the average knowledge score was lower than 75%. Certain questions covering new genetic technologies and testing practices were more commonly missed than questions asking about more basic aspects of hemophilia genetics, such as inheritance and carrier testing. Finally, many clinics report having access to a counselor, but it is oftentimes a hematologist or nurse who is providing genetic counseling services to patients. Given the inconsistency in knowledge among providers coupled with the high confidence in oneâs ability to counsel patients, it leaves room to question whether information about the genetics of hemophilia is being communicated to patients in the most appropriate and accurate manner
Finite gravitational action for higher derivative and stringy gravities
We generalize the local surface counterterm prescription suggested in
Einstein gravity for higher derivative (HD) and Weyl gravities. Explicitly, the
surface counterterm is found for three- and five-dimensional HD gravities. As a
result, the gravitational action for asymptotically AdS spaces is finite and
gravitational energy-momentum tensor is well-defined. The holographic trace
anomaly for d2 and d4 boundary (gauge) QFT dual to above HD gravity is
calculated from gravitational energy-momentum tensor. The calculation of AdS
black hole mass in HD gravity is presented within above prescrition. The
comparison with the standard prescription (using reference spacetime) is done.Comment: LaTeX file, 21 page
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