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We study the real-time dynamics of string breaking in quantum electrodynamics in one spatial dimension. A two-stage process with a clear separation of time and energy scales for the fermion-antifermion pair creation and subsequent charge separation leading to the screening of external charges is found. Going away from the traditional setup of external static charges, we establish the phenomenon of multiple string breaking by considering dynamical charges flying apart.

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Serial blood draws for the assessment of trauma patients' hemoglobin (sHgb) and hematocrit (sHct) is standard practice. A device that would allow for continuous real-time, non-invasive monitoring of hemoglobin and tissue perfusion would potentially improve recognition, monitoring and resuscitation of blood loss. We developed a device utilizing diffuse optical spectroscopy (DOS) technology that simultaneously measures tissue scattering and near-infrared (NIR) absorption to obtain non-invasive measurements of oxy- (Hb-O(2)), deoxyhemoglobin (Hb-R) concentrations and tissue hemoglobin concentration (THC) in an animal model of hypovolemic shock induced by successive blood withdrawals. Intubated New Zealand White rabbits (N = 16) were hemorrhaged via a femoral arterial line every 20 min until a 20% blood loss (10-15 cc kg(-1)) was achieved to attain hypovolemia. A broadband DOS probe placed on the inner thigh was used to measure muscle concentrations of Hb-O(2) and Hb-R, during blood withdrawal. THC and tissue hemoglobin saturation (S(T)O(2)) were calculated from DOS [Hb-O(2)] and [Hb-R]. Broadband DOS-measured values were compared against traditional invasive measurements: systemic sHgb, arterial oxygen saturation (S(a)O(2)) and venous oxygen saturation (S(v)O(2)) drawn from arterial and central venous blood. DOS and traditional invasive measurements versus blood loss were closely correlated (r(2) = 0.96) showing a decline with removal of blood. S(T)O(2) and [Hb-O(2)] followed similar trends with hemorrhage, while [Hb-R] remained relatively constant. These measurements may be limited to some extent by the inability to distinguish between hemoglobin and myoglobin contributions to DOS signals in tissue at this time. Broadband DOS provides a potential platform for reliable non-invasive measurements of tissue oxygenated and deoxygenated hemoglobin and may accurately reflect the degree of systemic hypovolemia and compromised tissue perfusion.

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Minimally invasive esophagectomy is emerging as an alternative option to open esophagectomy for benign and malignant esophageal diseases. This article provides a detailed review of the history of minimally invasive esophagectomy and an update on the currently accepted techniques for minimally invasive esophagectomy and its outcomes.

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Minimally invasive esophagectomy is emerging as an option in the management of benign and malignant esophageal diseases. With minimally invasive esophagectomy, the conventional laparotomy is substituted with laparoscopy and the open thoracotomy with thoracoscopy. This article discusses the surgical techniques and outcomes for a variety of minimally invasive esophagectomy options.

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The structural barriers to the use of hospice services by minority groups have been widely discussed. The attitudes of these groups are less clearly delineated. A series of focus groups with Mexicans was held in Michigan and Arizona. The participants were between the ages of 45 and 64 or over as well as providers of services to Mexicans. Regardless of length of time in the United States, participants were low on acculturation scores. These groups found important attitudes about the roles of the family, hospice services, and spirituality and the church in providing care to terminally ill individuals.

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Gastritis has a broad pathologic spectrum and anatomic distribution, as well as an evolving etiology. The Sydney pathologic classification of gastritis, which appeared in 1990 and was revised in 1994, emphasized the importance of combining etiologic, topographic, and morphologic criteria for establishing clinically useful diagnoses. Using this revised Sydney pathologic classification as a guide, we report a simpler and more practical radiologic approach to gastritis. We emphasize those types of gastritis that may be detected on radiologic examination and illustrate typical findings.

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BACKGROUND: Common bile duct injuries occur in 0.2% to 0.8% of laparoscopic cholecystectomies (LC). Intraoperative cholangiograms (IOCG) are a useful means of detecting common bile duct injuries in the operating room. METHODS: Data were retrospectively reviewed for patients referred for management of common duct injuries from 1996 to 2000. Cost data were obtained from hospital records. Legal settlements were obtained from published sources. RESULTS: Twenty-one patients (0.133%) were found to have bile duct injuries and incurred median hospital stays of 11.5 days at an average cost of $587,491. The average cost of those requiring reoperation was $669,134. The 21 cases in our sample had total charges of $10,819,767. Performing IOCG during each LC in Orange County would have cost $10,669,725. If extrapolated to state and nationwide levels, the savings is far greater. CONCLUSIONS: IOCG during LC is a cost-effective means of preventing the costs of delayed recognition of bile duct injuries.

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This unit presents characteristics and reaction conditions of the DNA-dependent DNA polymerases, including E. coli DNA polymerase I, Klenow fragment of E. coli DNA polymerase I, T4 DNA polymerase, native and modified T7 DNA polymerase, and Taq DNA polymerase.

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PURPOSE/OBJECTIVES: To develop a work-site cancer education and detection program targeted for Latino women and evaluate the effectiveness of the program in a firm with a majority of employees from Latino backgrounds. DESIGN: Program implementation and evaluation. SETTING: A Latino-owned industrial firm in Detroit, MI. SAMPLE: 560 of 857 female employees. Among the 202 women who were eligible for mammography, 142 participated in the screening. METHODS: Education and mammography were offered to women employees of Mexican Industries in Michigan. Education programs and mammograms were conducted at the work site. The programs were offered in English and Spanish. MAIN OUTCOME MEASURES: Participation in education and mammography and evaluation of program components. FINDINGS: Pre- and post-tests of knowledge indicated increases in the understanding of breast cancer. Evaluation of the educational program indicated high ratings of the presentations and materials. CONCLUSIONS: Work-site cancer education and detection programs are cost effective in firms where the majority of employees are from one ethnic/racial group and where the programs take into consideration the cultural background of the employees. IMPLICATIONS FOR NURSING PRACTICE: Cancer education and detection programs should consider the possibility of work-site interventions as well as the ethnic/racial background of employees during program development.

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OBJECTIVE: The radiologist and oncologist are often confident that biopsy will confirm their suspicion of recurrent disease, but a biopsy is performed to confirm the histologic diagnosis before beginning or altering therapy. We have examined data to determine how often the biopsied lesion represents recurrent disease from the primary tumor or is an instance of new cancer, and whether recurrent disease can be predicted. MATERIALS AND METHODS: We reviewed the medical and imaging records of 253 patients who underwent CT-guided biopsy of an abdominal or pelvic lesion between 1993 and 1996. Sixty-nine of the 253 patients had a previously diagnosed primary tumor and were being examined for possible tumor recurrence or metastasis. The images of these 69 patients were analyzed to determine if the pattern of disease was typical of recurrence or metastasis. RESULTS: In 55 of the 69 patients, the pattern was judged to be typical of metastatic or recurrent disease. Biopsy confirmed this suspicion in all 55 patients. In 14 of the 69 patients, the pattern of spread was judged not to be typical of recurrence or metastasis. These 14 patients were found to have a new primary tumor (n = 4), benign processes (n = 2), and recurrences (n = 8). CONCLUSION: Of the patients for whom radiographic findings suggested recurrence, we found no patients in whom a new primary tumor would have been missed if biopsy had been avoided. Data should now be acquired prospectively to determine whether it may be prudent to make treatment decisions on the basis of imaging findings alone, without histologic confirmation.

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Kinetically monitored, reverse transcriptase-initiated PCR (kinetic RT-PCR, kRT-PCR) is a novel application of kinetic PCR for high throughput transcript quantitation in total cellular RNA. The assay offers the simplicity and flexibility of an enzyme assay with distinct advantages over DNA microarray hybridization and SAGE technologies for certain applications. The reproducibility, sensitivity and accuracy of the kRT-PCR were assessed for yeast transcripts previously quantitated by a variety of methods including SAGE analysis. Changes in transcript levels between different genetic or physiological cell states were reproducibly quantitated with an accuracy of +/-20%. The assay was sufficiently sensitive to quantitate yeast transcripts over a range of more than five orders of magnitude, including low abundance transcripts encoding cell cycle and transcriptional regulators.

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Free jejunal grafts have been used in the surgical treatment of patients with carcinoma of the pharynx and upper esophagus. Post-operative complications, including swallowing difficulty, are frequent and radiographic assessment may be required. In this pictorial paper, we describe the surgical technique of free jejunal grafting of the pharyngoesophagus, and the radiographic appearances and clinical importance of early and delayed complications following the procedure. Dysphagia after placement of a jejunal graft is a common occurrence which is often multifactorial, and may be related to functional, anatomic, or a combination of factors.

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The purpose of this study was to correlate gastroesophageal reflux evaluated by 24-h pH study to esophageal motility, diameter of the esophagus and diaphragmatic hiatus, and patient age. We recorded radiographic findings from barium esophagrams in 91 patients (47 women, 44 men) with a mean age of 52 years (range 17-18 years), who had 24-h pH monitoring of the esophagus. All patients had one or more symptoms related to the upper aerodigestive system, and both studies were performed within 2 days of each other. The average diameters of the esophagus and hiatus were 24 mm and 19 mm respectively. The correlation coefficient (r) between patient age and diameter of the esophagus was -0.22. No correlation was found between the diameter of the hiatus and the size of the esophagus or patient age. Esophageal diameter is significantly wider in patients with esophagitis than in patients who have no esophagitis. Thirteen of 27 patients with absent primary peristalsis had abnormal pH results. The diameter of the esophagus may be affected by aging, but was not affected by the presence of dysmotility. The caliber of the hiatus was stable and was narrower than the diameter of the esophagus. The hiatus tended to be wider when esophagitis existed.

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OBJECTIVE: The purpose of this investigation was to determine the prevalence of lower esophageal mucosal rings and to correlate the relationship between these mucosal rings and the presence and anatomic level of symptoms evoked using a marshmallow bolus. SUBJECTS AND METHODS: Our prospective study included 130 patients who underwent barium examination of the esophagus. All patients completed a questionnaire regarding the anatomic location of their symptoms of dysphagia. In addition to a multiphasic examination of the esophagus, all patients also underwent fluoroscopic observation and videotaping while swallowing a marshmallow bolus; any symptoms that were provoked were recorded. RESULTS: Lower esophageal mucosal rings were shown in 26 (20%) of the 130 patients. The diameter of the rings was 9-12 mm in six patients, 13-20 mm in 18 patients, and larger than 20 mm in two patients. In 16 (62%) of the 26 patients, a marshmallow bolus became impacted at the ring; the impaction caused dysphagia in 12 (75%) of the 16 patients. In these 12 patients, dysphagia was referred to the neck in seven, the sternal angle in two, the mid chest in two, and the lower chest in one patient. None of the 12 patients had a pharyngeal or cervical esophageal abnormality that would account for their symptoms. CONCLUSION: Because proximal referral of symptoms is common in patients with lower esophageal mucosal rings, a thorough radiographic examination of the entire esophagus and esophagogastric region is required regardless of the level of their swallowing complaints.

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Cyclic di-GMP (c-di-GMP) is the specific nucleotide regulator of beta-1,4-glucan (cellulose) synthase in Acetobacter xylinum. The enzymes controlling turnover of c-di-GMP are diguanylate cyclase (DGC), which catalyzes its formation, and phosphodiesterase A (PDEA), which catalyzes its degradation. Following biochemical purification of DGC and PDEA, genes encoding isoforms of these enzymes have been isolated and found to be located on three distinct yet highly homologous operons for cyclic diguanylate, cdg1, cdg2, and cdg3. Within each cdg operon, a pdeA gene lies upstream of a dgc gene. cdg1 contains two additional flanking genes, cdg1a and cdg1d. cdg1a encodes a putative transcriptional activator, similar to AadR of Rhodopseudomonas palustris and FixK proteins of rhizobia. The deduced DGC and PDEA proteins have an identical motif structure of two lengthy domains in their C-terminal regions. These domains are also present in numerous bacterial proteins of undefined function. The N termini of the DGC and PDEA deduced proteins contain putative oxygen-sensing domains, based on similarity to domains on bacterial NifL and FixL proteins, respectively. Genetic disruption analyses demonstrated a physiological hierarchy among the cdg operons, such that cdg1 contributes 80% of cellular DGC and PDEA activities and cdg2 and cdg3 contribute 15 and 5%, respectively. Disruption of dgc genes markedly reduced in vivo cellulose production, demonstrating that c-di-GMP controls this process.

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OBJECTIVE: Published data from the Mayo Clinic gathered during the preendoscopic era were analyzed to show that the risk of subsequent colonic carcinoma is reduced in patients with benign-appearing polyps that are revealed by radiology who then undergo polypectomy. MATERIALS AND METHODS: Data from the Mayo Clinic gathered during a 6-year period before the availability of endoscopy were used to determine the effect on the subsequent risk of colonic carcinoma if the benign-appearing polyps initially revealed by radiology had been removed rather than left in place and followed up by serial barium enemas. Data were from 226 patients with benign-appearing polypoid lesions of the colon that were 1 cm in diameter or larger and had been followed up by periodic barium enemas. The period of radiologic surveillance was 12-229 months (mean, 68 months). Between two and 17 barium enemas (mean, 5.2) were performed on each patient. The clinical follow-up period was 12-242 months (mean, 140 months). RESULTS: Twenty-one adenocarcinomas developed at the site of the index polypoid lesion as found on follow-up barium enema examinations of these patients. Eleven additional adenocarcinomas of the colon were found at sites remote from that of the index lesion. If the index polyp had been removed when initially diagnosed radiologically, 66% fewer subsequent carcinomas would have occurred in these patients during the average of 11 years of clinical follow-up. CONCLUSION: Excision of benign-appearing polyps found on initial barium enema examinations would result in a significant decrease in the subsequent risk of colonic adenocarcinoma.

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