Publications by authors named "Leo K"

We realize p- and n-type doping of the organic semiconductor zinc-phthalocyanine using a novel strong organic donor. This allows us to demonstrate the first stable and reproducible organic p-n homojunctions. The diodes show very high built-in potentials, attractive, e.

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Nasopharyngeal carcinoma is a common malignancy in the Asian Chinese population. First-line treatment consists primarily of radiotherapy and chemotherapy, with salvage surgery if recurrence occurs. Patients with this tumours frequently present years after radiotherapy with symptomatic temporal lobe cystic lesions and a diagnostic problem arises.

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A major product recovered from the processing and recycling of construction and demolition (C&D) debris is screened soil, also referred to as fines. A proposed reuse option for C&D debris fines is fill material, typically in construction projects as a substitute for natural soil. Waste material that is reused in a manner similar to soil must first be characterized to examine potential risks to human health and the environment.

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Stimulation of isolated rat Kupffer cells by viable Leptospira interrogans, Treponema pallidum and Borrelia garinii elicited cellular responses resulting in the release of different tumor necrosis factor alpha (TNF-alpha) levels, depending on the spirochetes. L. interrogans induced TNF-alpha levels higher than those achieved with B.

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We report that intraperitoneal injection of Chlamydia pneumoniae purified elementary bodies (EBs) in the hamster causes a systemic infection allowing the isolation of viable chlamydiae from several organs for several days post-infection (p.i.).

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We have directly time resolved coherent phonon oscillations in quasi-one-dimensional organic crystals of MePTCDI ( N-N'-dimethylperylene-3,4,9,10-dicarboximide), using femtosecond pump-probe experiments. We observe both higher-energy oscillations caused by intramolecular vibrations (internal phonons) and, for the first time in a quasi-one-dimensional organic system, lower-energy modulations which are related to coherent lattice phonons (external phonons). For internal A(g) vibrations, the coherence decay time of about 2 ps is almost independent of the mode.

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We investigate the energy spectrum and the electron dynamics of a band in a semiconductor superlattice as a function of the electric field. Linear optical spectroscopy shows that, for high fields, the well-known localization of the Bloch states is followed by a field-induced delocalization, associated with Zener breakdown. Using time-resolved measurements, we observe Bloch oscillations in a regime where they are damped by Zener breakdown.

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We observe that the oscillatory motion of photoinjected electron-hole pairs in a biased semiconductor superlattice (Bloch oscillation) is accompanied by a coherent quasi-dc current that is generated by the interaction of the carriers with the self-induced oscillating field. It is shown that this novel macroscopic quantum effect, which is a coherent analog of the Shapiro effect observed in Josephson junctions, can be controlled by changing the spectral position of the exciting laser pulse, which in turn determines the amplitude and phase of the wave packet oscillations. It is thereby possible to coherently drive the electrons either downwards or upwards in the potential of the static field.

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Delivery of quality patient care and management of patient outcomes is critical to the success of academic medical centers in the ever-changing health care market. The University of Iowa Hospitals and Clinics (UIHC) promotes quality care through the provision of organizational structures and processes that are described in this article. In addition, quality of care and outcomes management are described by members in various roles within the UIHC health care system.

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Background And Purpose: Exercise programs are more likely to be successful when they are based on research that predicts the outcomes of such training. This study determined the effect of submaximal rhythmic handgrip training on rhythmic handgrip endurance or work (RHW), isometric handgrip endurance time (IHE), and maximal voluntary isometric contraction for the handgrip force (MVIC) (in newtons).

Subjects: Twenty-four male subjects (mean age=26.

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Objective: The Quality of Well Being index (QWB) and the SF-36 are questionnaires that have received widespread use in outcomes research. The relationship between the QWB index and the SF-36 was studied in patients receiving total hip or knee replacement because of primary osteoarthritis, and the health status of these individuals was contrasted to that of the general population.

Design: The QWB and SF-36 were both administered preoperatively and postoperatively and at 3 and 6 months in individuals with hip or knee replacement.

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The critical decisions of which artemisinin derivative(s) to use and by which route(s) of administration for falciparum malaria are complex scientifically and politically. Despite the need for additional pharmacokinetic, pharmacodynamic and toxicokinetic data, these drugs are too important to delay concise, rational recommendations any longer. These types of decisions must be made now, implemented on a multinational level with WHO leadership, and revised as new findings emerge.

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Penclomedine is a multi-chlorinated alpha-picoline derivative that has demonstrated activity in several murine breast cancer models and is currently in clinical testing for use against solid tumors. This study evaluates the metabolism of penclomedine in several in vitro hepatic models, including microsomes, fresh liver slices, and the isolated perfused rat liver (IPRL). Both human and mouse liver slices as well as human and mouse liver microsomes under aerobic conditions resulted in limited metabolism of penclomedine to several oxidized metabolites, including penclomic acid, 4-demethylpenclomic acid, and 4-demethylpenclomedine.

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Arteether (AE) is primarily deethylated to dihydroqinghaosu (DQHS) in rats and humans. Conversion of AE to DQHS was impaired in microsomes from rats infected with Plasmodium berghei. The Km for AE was 175.

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We investigate high-quality evaporated dye layers of N, N'-dimethylperylene-3,4:9,10-bis-discarboximide of varying thicknesses, using temperature-dependent luminescence. Layers with a nominal thickness much less than a monolayer show monomer emission similar to that of dilute solutions. With increasing layer thickness, the luminescence is dominated by excimer transitions.

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Halofantrine and mefloquine are antimalarial drugs used in the treatment of malaria, including that caused by chloroquine-resistant Plasmodium falciparum. Reports of drug-associated adverse reactions, including sudden death in one patient, have prompted concerns over the safety of halofantrine and the potential for drug-drug interactions. We used the isolated perfused rat liver (IPRL) model to investigate a possible hepatic metabolic or pharmacokinetic drug-drug interaction between halofantrine and mefloquine.

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Physical therapists may use varied treatment protocols for the acute care of patients with to hip or knee replacements. The purpose of this study was to develop, via consensus, a standardized treatment program for patients receiving total hip or knee replacement for primary osteoarthritis. Eighteen clinicians nationwide participated in a three-round consensus process.

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Clinical practice databases are frequently used to assess outcomes in various medical specialties. Formulating a computerized physical therapy medical record requires standardization of clinical assessments among the users. The purpose of this article is to describe an acute care physical therapy database system that emphasizes high-quality measures of function.

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