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The vibrational spectra of H3+Ar2,3 and D3+Ar2,3 are investigated in the 2000 cm−1 to 4500 cm−1 region through a combination of mass-selected infrared laser photodissociation spectroscopy and computational work including the effects of anharmonicity. In the reduced symmetry of the di-argon complex, vibrational activity is detected in the regions of both the symmetric and antisymmetric hydrogen stretching modes of H3+. The tri-argon complex restores the D3h symmetry of the H3+ ion, with a concomitant reduction in the vibrational activity that is limited to the region of the antisymmetric stretch. Throughout these spectra, additional bands are detected beyond those predicted with harmonic vibrational theory. Anharmonic theory is able to reproduce some of the additional bands, with varying degrees of success. [ABSTRACT FROM AUTHOR]

There have been many variants of the active power filter proposed and these variations cover both the circuit topology and the control system employed. Some of the control variants reflect different control objectives but there are still many variants within similar objectives. The available control techniques are described and contrasted in a structured way to identify their performance strengths. Objectives are classified by the supply current components to be corrected and by the response required to distorted grid voltage. The various signal transformations are described in terms of their impact on the distortion identification problem. Time-domain, frequency-domain, instantaneous power and impedance synthesis methods are examined. Additional control functions such as DC-bus voltage and current reference following are also discussed. It is found that a key difference between control methods is the way in which current distortion is treated in the presence of distorted grid voltage. [ABSTRACT FROM AUTHOR]

Examines breast and ovarian cancer risks in BRCA1 and BRCA2 mutation carriers. Percentage of all breast and ovarian cancers that result from an inherited disposition; Reasons for the differed results of studies on the risk of developing breast and ovarian cancer in women that carry such mutations; Information on the population that comprised the index cases; Role of genetic risk factors in the development of breast and ovarian cancers.

The vibrational spectra of H 3 + Ar 2,3 and D 3 + Ar 2,3 region through a combination of mass-selected infrared laser photodissociation spectroscopy and computational work including the effects of anharmonicity. In the reduced symmetry of the di-argon complex, vibrational activity is detected in the regions of both the symmetric and antisymmetric hydrogen stretching modes of H -1 to 4500 cm -1 symmetry of the H 3 + . The tri-argon complex restores the D 3h symmetry of the H 3 + ion, with a concomitant reduction in the vibrational activity that is limited to the region of the antisymmetric stretch. Throughout these spectra, additional bands are detected beyond those predicted with harmonic vibrational theory. Anharmonic theory is able to reproduce some of the additional bands, with varying degrees of success.

Adoption of laparoscopic colorectal surgery has been slow. In the United States, of approximately 250,000 colectomies each year, only 5% to 15% of these cases are being done laparoscopically. Laparoscopic colorectal surgery can be performed successfully on patients for both benign and malignant conditions in any anatomic location of the colon and rectum. The COST trial definitively established that laparoscopic colon surgery for cancer had similar rates of local recurrence and survival compared to open surgery, with better short-term outcomes. It demonstrated that laparoscopic resections resulted in shorter hospital stays, decreased IV narcotics and oral analgesics, and improved quality of life within two weeks of surgery. In the authors' clinical experience of more than 1500 laparoscopic surgeries, patients who undergo laparoscopic colorectal surgery experience decreased rates of wound infection, hernia, and bowel obstruction. One of the challenges of laparoscopic colorectal surgery is standardizing these complex, minimally invasive procedures in the operating room. With standard techniques, one can create optimal outcomes for patients, minimizing perioperative complications and maximizing oncologic results. This paper describes a sequenced step approach for each procedure to facilitate this. Left colectomy follows a nine-step process, and right colectomy follows a four-step process. Both of these procedures are described in detail. The newest horizon in minimally invasive surgery is single incision surgery, which allows for colorectal resections through a single 2.5 cm incision, producing an excellent cosmetic result. Based on this chapter, we advocate the laparoscopic approach be used as the primary method for colorectal surgery.

This article reviews pulmonary function tests (quantitative measurements of physiologic functioning of lungs, chest wall, and respiratory muscles) as valuable tools for the diagnosis and management of chronic respiratory disease in adolescents. Advances in technology have made pulmonary function testing more available and, for some tests, easier to perform. Pulmonary function evaluation is used for diagnosis of pulmonary disease. Testing will identify abnormal physiologic processes that result in obstructive or restrictive pulmonary disease and, together with a complete history, physical examination, and other tests, help to determine the specific etiology. Pulmonary function measurement may be used to manage a patientís disease over time. Quantitative evaluation of the response to many specific therapies, such as asthma medications and environmental control, can only be achieved by measuring pulmonary function. Monitoring pulmonary toxicity of medications, such as chemotherapeutic agents, is also done by measuring pulmonary function. In many patients with chronic pulmonary disease, such as cystic fibrosis, the pulmonary function laboratory can be used to assess the patient's physiologic limitation.

Every young person with a respiratory disability should be given the opportunity to maximize his or her exercise potential. Conditions such as asthma, affecting some 14 to 15 million people and cystic fibrosis (CF), affecting about 30,000 people in the U.S., may exclude young people from sports participation. And yet regular aerobic exercise and weight training have been shown to provide significant psychological and physical benefits to people with lung disease and diseases of the respiratory muscles and chest wall. The authors document the effects of asthma, CF, and neuromuscular diseases on aerobic exercise to prevent unnecessary limitations on participation due to inaccurate preconceived notions of sports of exercise capacity in chronically ill adolescents.

Study Objective: A preliminary study comparing the efficacy and safety of the flutter device (Flutter) to standard, manual chest physiotherapy (CPT) in hospitalized cystic fibrosis (CF) patients undergoing an acute pulmonary exacerbation., Design: Open label, comparative trial with alternate assignment., Setting: Community and childrens' hospital acute-care wards., Participants: Twenty-two CF patients (ages 8 to 44 years) undergoing a total of 33 hospitalizations for acute pulmonary exacerbation., Interventions: Complete pulmonary function tests (PFTs) were done at baseline (admission), weekly, and upon discharge from the hospital. Clinical score (CS) was determined at the time of hospital admission and at discharge. Participants were assigned to receive supervised Flutter therapy or standard, manual CPT four times per day during the hospitalization. Patients were monitored for complications, including hemoptysis, hypoxemia, and pneumothorax., Results: The groups (CPT and Flutter) did not differ at baseline in demographics or Shwachman score, nor was length of hospitalization different. Significant improvements were noted from admission to discharge in CS and PFT results within each group. Mean percent change in CS and PFT results between CPT and Flutter groups showed no significant difference from hospital admission to discharge. Subsequent power analysis using the observed difference in percent change from admission to discharge for FEV1 indicated that to attain 80% power at alpha = 0.05, a sample of 219 subjects in each group would be necessary., Summary: Comparative trials of airway clearance techniques with sufficient sample size are lacking. Although the Flutter appears to be a useful device for independent, cost-effective, and safe administration of CPT in this pilot study, a much larger clinical trial would be necessary to make definitive conclusions.

Stasis of viscid secretions in cystic fibrosis (CF) leads to chronic infection, inflammation, and lung destruction. Chest physiotherapy (CPT) has been used for many years to assist in the removal of these secretions. However, the need for independently administered CPT exists, particularly for adolescents and the older CF patient. Two devices, the intrapulmonary percussive ventilator (IPV) and the Flutter device (Flutter) have been promoted for this purpose. This study compares these devices to standard, manual CPT. There was no difference in sputum quantity produced with any method studied. Transiently lower oxygen saturation was noted with standard CPT compared with the IPV and Flutter. Inconsistent but significant improvements in flow rates were noted with the two devices compared to standard CPT. Important trends to lower lung volumes, probably indicating decreased air trapping, were also noted with all three therapies at 1 and 4 hours after administration. There were no adverse effects with any treatment regimen. Larger and longer studies of these devices compared to standard CPT and with each other are warranted to assess their value for independent administration of CPT in CF patients and to determine long-term effects on maintenance of pulmonary function.

The role of the medial efferent system in altering and/or regulating outer hair cell function in the mammalian cochlea has been proposed by a number of investigators. This study measured contralateral suppression of distortion product otoacoustic emissions (DPOAEs) in cystic fibrosis (CF) patients, treated for lung infections with low to moderate cumulative doses of tobramycin, to ascertain the contributions of the efferent-based mechanisms in the development of ototoxicity. The results showed significant suppression of DPOAEs in tobramycin-treated children compared to both nondrug-treated CF and normal children of similar ages. Since DPOAE amplitudes were comparable across the drug-treated and control groups of subjects, pronounced DPOAE suppression in the drug-treated group may be attributed to the instability of the cochlear amplifier induced by the tobramycin treatment. These findings also suggest that enhanced contralateral suppression may be the first sign of a developing ototoxicity.

Background: Intraoperative ultrasound has been shown to provide significant assistance in operative staging and management of patients with liver tumors during open surgery. The availability of the 5.0-7.5 Mhz semiflexible ultrasound transducer with gray-scale, color and spectral Doppler capabilities can provide similar information laparoscopically., Methods: Twenty-four consecutive patients with liver tumors (18 metastatic and six primary), in technically resectable locations determined by a variety of conventional imaging studies, were brought to the operating room. There was no known extrahepatic disease, and there was no recurrence at the primary site in the metastatic subgroup. These patients were evaluated intraoperatively with laparoscopy and intraoperative laparoscopic ultrasound to assess resectability prior to performing a major laparotomy. Laparoscopy was successful in 23 of the patients and in 19 of 23, laparoscopic ultrasound was also employed, using the 5.0-7.5 MHz semiflexible transducer. The use of the open entry technique, selection of alternate entry sites, coupled with expertise in laparoscopic lysis of adhesions, has allowed safe laparoscopic tumor staging., Results: The laparoscopic evaluation was aborted only once due to dense adhesions, despite the fact that 67% of the patients had undergone previous abdominal surgery. There was only one complication: bleeding from a liver biopsy in an unresectable cirrhotic patient, necessitating laparotomy. Laparoscopy and ultrasound together predicted nonresectability in six of eight unresectable patients, all of whom were spared an unnecessary laparotomy., Conclusions: Laparoscopic ultrasonographic evaluation for the staging of liver tumors should be a prerequisite to definitive laparotomy, with the objective of avoiding unnecessary surgery.