Tailoring electron beams with high-frequency self-assembled magnetic charged particle micro optics.

Tunable electromagnets and corresponding devices, such as magnetic lenses or stigmators, are the backbone of high-energy charged particle optical instruments, such as electron microscopes, because they provide higher optical power, stability, and lower aberrations compared to their electric counterparts. However, electromagnets are typically macroscopic (super-)conducting coils, which cannot generate swiftly changing magnetic fields, require active cooling, and are structurally bulky, making them unsuitable for fast beam manipulation, multibeam instruments, and miniaturized applications. Here, we present an on-chip microsized magnetic charged particle optics realized via a self-assembling micro-origami process. These micro-electromagnets can generate alternating magnetic fields of about ±100 mT up to a hundred MHz, supplying sufficiently large optical power for a large number of charged particle optics applications. That particular includes fast spatiotemporal electron beam modulation such as electron beam deflection, focusing, and wave front shaping as required for stroboscopic imaging.

Treatment of chronic gout. Can we determine when urate stores are depleted enough to prevent attacks of gout?

OBJECTIVE: To determine if lowering of serum uric acid (SUA) concentrations below 6 mg/dl or longer duration of lowered SUA will result in depletion of urate crystals from the knee joints and prevent further attacks of gout. METHODS: A prospective study was initiated 10 years ago at Philadelphia VA Medical Center to attempt to maintain SUA levels of patients with crystal proven gout at < 6.0 mg/dl. We recalled all 57 patients who were available during 1999. Patients were divided into 2 groups: Group A, with SUA still > 6 mg/dl, and Group B, with SUA < or = 6 mg/dl. A knee joint aspirate was requested from all asymptomatic Group B patients and many in Group A. Aspirates were examined by polarized light microscopy for identification of crystals. RESULTS: There were no differences between the groups in age, sex, duration of gout, or serum creatinine. Group A (n = 38) had a mean of 6 attacks of gout for the recent year, those with tophi having the most frequent attacks. Among the 16 patients in this group who agreed to knee aspiration, monosodium urate (MSU) crystals were found in 14, although they were asymptomatic at the time. Nineteen patients (Group B) were able to maintain serum urate levels < or = 6 mg/dl for > 12 months. Nearly half of them had no attack of gout for 2 or more years, with a mean of 1 attack in the last year for the whole group. Three patients in whom tophi were found did not have major flares of gout within the past year. Knee joint aspiration was done on 16 asymptomatic patients. Seven (44%) still had MSU crystals present in their knees. Patients in this group who were taking prophylactic colchicine did not differ with respect to the character of synovial fluid from those who had discontinued it for up to several years, although the frequency of attacks was less in those who continued colchicine. CONCLUSION: A majority of patients were able to deplete urate crystal stores in their knee joint fluids when their SUA levels were kept to < or = 6 mg/dl for several years. The mechanisms for persistence in some patients, and whether such crystals have clinical implications, are not known. Patients with chronic gout need serum urate concentrations to be kept low to prevent further attacks.

Primary care physicians' attitudes, knowledge, and practices related to cancer clinical trials.

BACKGROUND: Participation of patients in cancer clinical trials is disappointingly low and several physician-based factors are thought to be responsible. METHODS: In 1998-1999, the National Cancer Institute (NCI) conducted a probability survey of three primary care physician groups to gain a better understanding of the barriers to clinical-trial patient accrual from their perspective. RESULTS: Findings from this survey of 706 primary care physicians indicate that the vast majority (98%) refer their patients with cancer to a specialist for cancer treatment and rarely bring up the topic of cancer clinical trials. Frequently cited reasons for not mentioning clinical trials are preferring to leave that discussion to the oncologist (41%) and being unaware of any clinical trials that may be available for the patient (37%). CONCLUSION: Primary care physicians may represent an important untapped resource for introducing the concept of clinical trials as an option to newly diagnosed cancer patients.

Oral-dental radiographic examination technique.

In general practice, dental radiography is currently being performed more often as a treatment planning technique during routine dental prophylactic procedures than ever before. Medical radiography units, although still useful for the determination of bone cancer, mineral deficiencies, and fracture studies, are yielding to the use of more versatile dental radiograph machines that are being installed in the dental operatory and expose only the dental film. Currently, the technology of intraoral digital radiography, photography, and videography is available. Digital images can be enhanced, preserved on Polaroid film, or stored directly into computer data banks, without the use of dental film. This article acquaints the reader with digital technology, but deals primarily with traditional film-based oral-dental radiographic examination technique. The equipment and techniques described are affordable and well within the capabilities of the general practitioner. The importance of being able to produce dental radiographs of excellent quality is basic when providing competent dental care.

Bilateral mandibular condylectomy in a cat.

A six year old cat with a chronically luxating jaw was treated by bilateral condylectomy. The etiology of the chronic luxation was unilateral temporomandibular joint dysplasia.

Health communications to older Americans as a special population. The National Cancer Institute's consumer-based approach.

BACKGROUND: Focus groups conducted by the National Cancer Institute in 1990 revealed that a multitude of fears, anxieties, and negative perceptions underlie the attitudes and behaviors of older Americans with respect to cancer. This central finding suggested that a communications approach aimed at encouraging cancer screening and early detection behavior among older Americans would need to consider the pervasiveness of these fears and not focus on health benefits alone. METHODS: To explore consumer reactions to a new fear acknowledgment/self-empowerment communications strategy, three alternative positioning ads (or concepts) reflecting the strategy were prepared and evaluated through 29 in-depth interviews with members of the target audience. RESULTS: Results confirmed the underlying fear of cancer found in earlier focus groups, a step which was critical for assessing the general strategic approach embodied in the ads. The idea that older people operate from a base of widespread fear and need to be empowered to take charge of their health resonates with and makes sense to the intended audience. A single ad concept was developed from the original three that reflects the feedback of the interviewees. CONCLUSIONS: Using the approach of fear acknowledgment/self-empowerment with older Americans is likely to affect the target audience positively. As a whole, respondents in the study considered the ads that embodied this strategy to be empathetic, helpful, and easy to relate to.

Determination of a metabolite of the herbicide pyridate in drinking and groundwater using high-performance liquid chromatography with amperometric detection.

The main metabolite of the herbicide pyridate is 3-phenyl-4-hydroxy-6-chlorpyridazine (CL9673). A high-performance liquid chromatographic method with amperometric detection is described for determining CL9673 at residue levels in water samples. Sample preconcentration is performed by passage through a C18 extraction cartridge. A recovery study using tap water samples spiked with CL9673 at a concentration of 0.1 micrograms/l showed a recovery of 84.8% (coefficient of variation 6.2%). The method is suitable for the determination of CL9673 in drinking and groundwater.

Problems associated with veterinary dental radiography.

Veterinarians have been radiographing animal skulls for many years, but sophisticated dentistry was not widely used until the 1970s. Elevated awareness of veterinary dental techniques has led to the need for producing accurate radiographic images of the teeth and periodontal structures. Many problems arise for the clinician who treats small animals who has, before this time, radiographed the skull of dogs and cats solely for the purpose of assessing neoplastic, infectious, or traumatic disease of the mandible, maxilla, or calvarium and now desires to perform dental radiography. This chapter will describe the advantages and disadvantages of some of the more common types of radiographic equipment and supplies, discuss extraoral and intraoral radiographic positioning and technique, identify anatomic landmarks and diagnostic features of intraoral radiography, and offer suggestions concerning the art of using dental radiography in veterinary practice.

Quinidine-induced agranulocytosis.

In a 75-year-old man, agranulocytosis and septicemia developed after eight weeks of quinidine sulfate therapy. An IgG antibody requiring the presence of quinidine was shown by complement-dependent leukocytotoxicity and leukoagglutination reactions. The antibody did not cross-react with quinine and was active against WBCs obtained from normal subjects and from the patient himself.