High-power beam transport through a hollow-core photonic bandgap fiber.

We investigate the use of a seven-cell hollow-core photonic bandgap fiber for transport of CW laser radiation from a single-mode, narrow-linewidth, high-power fiber laser amplifier. Over 90% of the amplifier output was coupled successfully and transmitted through the fiber in a near-Gaussian mode, with negligible backreflection into the source. 100 W of power was successfully transmitted continuously without damage and 160 W of power was transmitted briefly before the onset of thermal lensing in the coupling optics.

Phase locking and supermode selection in multicore photonic crystal fiber lasers with a large doped area.

We report on the laser properties of multicore photonic crystal fiber lasers. A stable phase locking of six- and seven-core structures through evanescent coupling is observed. Effective supermode selection is obtained by using both diffraction losses and the Talbot effect. A pure in-phase supermode is obtained (1.1 times diffraction limited). The laser operating in this mode has a slope efficiency of 70% with up to 44 W of output power. The modal area of the in-phase supermode multicore fiber is 1150 microm2, which makes it, to our knowledge, the single-mode fiber laser with the largest mode field area. In-phase laser action is stable when the fiber is bent.

Orbital angular momentum exchange in the interaction of twisted light with molecules.

In the interaction of molecules with light endowed with orbital angular momentum, an exchange of orbital angular momentum in an electric dipole transition occurs only between the light and the center of mass motion; i.e., internal "electronic-type" motion does not participate in any exchange of orbital angular momentum in a dipole transition. A quadrupole transition is the lowest electric multipolar process in which an exchange of orbital angular momentum can occur between the light, the internal motion, and the center of mass motion. This rules out experiments seeking to observe exchange of orbital angular momentum between light beams and the internal motion in electric dipole transitions.

Quantum theory of spontaneous emission by real moving atoms.

We outline the solution of a fundamental problem in quantum theory which has hitherto lacked a proper solution, namely, finding the requisite quantum theoretical framework guaranteeing that the calculated inverse spontaneous emission rate of a moving atom, as a composite system of charged particles interacting with the Maxwell field, is slowed down exactly as in time dilation.

Observer reliability in ankle radiographic measurements.

We analyzed 50 sets of ankle radiographs to determine the interobserver and intraobserver reliability when obtaining common linear and angular measurements. The radiographs were divided into two groups: one group included 25 normal ankles, and the second group included 25 fractured ankles. Each set of radiographs was evaluated independently by four different observers on two separate occasions under controlled conditions. Six radiographic parameters were measured on all 50 sets of films: syndesmosis A, syndesmosis B, syndesmosis C, the medial clear space, and the talocrural and bimalleolar angles. On the 25 sets of fracture films, four additional measurements of fracture displacement were included: displacement of the medial malleolus (mortise), displacement of the lateral malleolus (AP and lateral), and displacement of the posterior malleolus. Reliability was evaluated with an analysis of variance intraclass correlation coefficient. Among the examiners, 9 of the 10 parameters could be measured reliably. Intraobserver reliability was found to increase with the experience of the examiner.

Identifying true lidocaine allergy.

Allergies to local anesthetics are rare. More often, the allergic response is caused by a metabolite, preservative or unrelated substance. At times, an apparent allergic reaction can be brought on by anxiety. An idiopathic reaction to lidocaine is described, and allergy testing is discussed.

The oral hygiene performance test: development and validation of dental dexterity scale for the elderly.

This paper describes a test which was developed for use in assessing the functional oral hygiene status of an elderly population. The instrument was tested among 80 community-dwelling elderly subjects 65 or more years old. The instrument, the Oral Hygiene Performance Test [OHPT], is a direct-observation measure which objectively quantifies the individual's ability to perform oral hygiene and thus reduces subjective evaluation. The test utilized several items from other already-validated instruments currently in use in geriatric medicine to assess functional abilities in a geriatric population. Additional items were developed by the research team and were included in this 17-item test. The OHPT was validated with common measures of physical function and direct-observation measures. Construct validity was assessed by comparison of the OHPT scores with other commonly used measures of other dimensions. The instrument proved to be reliable and demonstrated construct as well as concurrent validity. It appears that the OHPT can prove useful to clinicians in assessing the oral physical function of elderly patients with regard to their maintenance of oral hygiene. Because the OHPT is a direct-observation instrument, it can even elicit higher functions in elderly patients. While effective among the studied population, the instrument may still need to be validated among more diverse populations, such as various ethnic groups and demented or severely impaired populations.

Ketorolac-induced bronchospasm in an aspirin-intolerant patient.

A patient, in her mid-twenties, presented with "severe polypoid sinusitis" for sphenoethmoidectomy under general anesthesia. Upon preoperative medical evaluation, it was discovered that she was "allergic" to aspirin and suffered from stress-induced asthma. Before induction of anesthesia, the patient was administered intravenous hydrocortisone and two puffs of her albuterol inhaler to prevent a possible bronchospasm due to stress of the surgery or irritation from the endotracheal tube or other stimuli. The patient was maintained throughout the case with an inhalation anesthetic for its bronchodilatory effect. The surgery proceeded unremarkably, and the patient was then administered ketorolac tromethamine for postoperative pain. After an awake extubation, the patient was transferred to the postanesthesia care unit (PACU) for further monitoring. After 15 min in the PACU, the patient claimed having difficulty breathing. She was then administered terbutaline to produce bronchodilation, but her condition did not improve. Shortly thereafter, aminophylline, midazolam, and methylprednisolone were also administered intravenously. Meanwhile, the patient had to be reintubated and placed on ventilator support with heavy sedation. At this point, it was discovered that ketorolac may have been the cause of this response. Although the patient's condition began to improve, the histamine H1- and H2-receptor blockers diphenhydramine and ranitidine were coadministered. When the patient's condition returned toward normal, she was extubated. The patient's breathing continued to improve. Thereafter, she was transferred to an overnight observation bed and later dismissed to return home. The patient was advised of the episode and warned against future intake of other nonsteroidal antiinflammatory drugs.

Dissociative-sedation: a new concept.

Dissociative-sedation, a sedation technique found to be particularly applicable in the pediatric dental patient will be presented in this article. No attempt should be made by the inexperienced dentist to produce the state described. Rather, consultation with and referral to an appropriately trained physician or dental anesthesiologist is in order.

Anatomical considerations for mandibular anesthesia in patients with hemifacial microsomia.

Hemifacial microsomia is a congenital abnormality of the structures derived from the first and second branchial arches. The severity of this disorder is variable and affects the anatomical landmarks essential for establishing the proper pathway for needle insertion prior to deposition of the local anesthetic solution to attain regional mandibular anesthesia preparatory to dental procedures. This paper describes normal anatomical considerations for regional anesthesia in the mandibular arch, deviations in normal anatomy found in patients with hemifacial microsomia, the rationale for suggesting modifications to standard techniques for mandibular anesthesia in patients with this disorder, and presents ways for the dentist to achieve anesthesia (analgesia) on the affected side of the mandibular arch in patients with hemifacial microsomia.

Relationship between leadership styles of hospital pharmacists and perceptions of work-unit effectiveness.

Relationships between hospital pharmacists' perceptions of their own and their immediate supervisors' leadership styles and their perceptions of the effectiveness of their work units were examined. Pharmacists practicing in 12 large Chicago-area hospitals were asked to complete a four-part questionnaire that consisted of demographic questions, the LEADSelf instrument, the LEADOther instrument, and a measure of perceived work unit effectiveness. Respondents' primary, secondary, and combination leadership styles and their degree of style adaptability were determined and compared with the primary, secondary, and combination leadership styles and style adaptability of their immediate supervisors and with their perceptions of the effectiveness of their work units. Pharmacists involved in providing clinical or drug information services and pharmacists responsible for purchasing activities perceived their work units to be most and least effective, respectively. Most respondents perceived their primary leadership style to be high task-high relationship, but only 32% perceived their immediate supervisors to exhibit this style. Pharmacists who perceived their immediate supervisors to have high relationship leadership styles (based on primary and combination style classifications) had significantly more favorable perceptions of the effectiveness of their work units than did pharmacists who perceived their supervisors to exhibit low relationship styles. Respondents' perceptions of their supervisors' style adaptability were positively and significantly correlated with their perceptions of work-unit effectiveness. Respondents who thought their supervisors' leadership styles were more adaptable than their own had the most favorable perceptions of work-unit effectiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

Physostigmine reversal of drug-induced paradoxical excitement.

Paradoxical excitement associated with intravenous conscious-sedation in a patient undergoing dental surgery was successfully reversed with 1.0 mg physostigmine. Physostigmine is felt to have exerted this effect by 2 mechanisms: the re-establishment of homeostasis in the CNS via augmented cholinergic pathways with the net result being thalamacocortical excitation, and cholinergically-mediated increase in cerebral blood flow increasing the rate of redistribution of the intravenous sedative agents used. The most commonly encountered side-effects of physostigmine used to reverse parodoxical excitement, emergence delirium, or prolonged narcosis are bradycardia, nausea, and/or vomiting. The incidence of these side-effects is low in doses, below 2.0 mg/70 kg. body weight.

Anesthetic management. Historical, present, future.

This article deals with specific agents that either have been or are being employed for the production of general anesthesia or sedative states for the control of pain or anxiety in the dental setting. Change, progress, trends, and contributions to the field of dental anesthesia made by dentists are stressed. In addition, a brief synopsis of the most popular present-day techniques and agents is discussed. Finally, the future of the field of dental anesthesia and the role to be played by dentists is considered.

Stress-induced hypertensive reaction in a patient receiving monoamine oxidase inhibitors: report of a case.

A case illustrating the potential for hypertensive crisis in the ambulatory dental patient under treatment with monoamine oxidase inhibitors is presented. It is somewhat unique in that it appears to contradict much of the literature, which states that circulating, endogenous catecholamines are not expected to be a factor in initiating this potentially severe complication. Since this patient had not taken any food or drink prior to the appointment, it may be conjectured that endogenous catecholamines released as a result of stress and dental pain initiated the crisis.