RESUMEN
We realized a quantum geometric "charge" pump for a Bose-Einstein condensate (BEC) in the lowest Bloch band of a novel bipartite magnetic lattice. Topological charge pumps in filled bands yield quantized pumping set by the global-topological-properties of the bands. In contrast, our geometric charge pump for a BEC occupying just a single crystal momentum state exhibits nonquantized charge pumping set by local-geometrical-properties of the band structure. Like topological charge pumps, for each pump cycle we observed an overall displacement (here, not quantized) and a temporal modulation of the atomic wave packet's position in each unit cell, i.e., the polarization.
RESUMEN
We directly measured the normalized s-wave scattering cross-section of ultracold 40K atoms across a magnetic-field Feshbach resonance by colliding pairs of degenerate Fermi gases (DFGs) and imaging the scattered atoms. We extracted the scattered fraction for a range of bias magnetic fields, and measured the resonance location to be B0 = 20.206(15) mT with width Δ = 1.0(5) mT. To optimize the signal-to-noise ratio of atom number in scattering images, we developed techniques to interpret absorption images in a regime where recoil induced detuning corrections are significant. These imaging techniques are generally applicable to experiments with lighter alkalis that would benefit from maximizing signal-to-noise ratio on atom number counting at the expense of spatial imaging resolution.
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Infection of freshly isolated and cryopreserved lymphocytes with Epstein-Barr virus (EBV) leads to the establishment of human B lymphoblastoid cell lines (LCLs). Techniques for optimal infection of the lymphocytes are vital for the establishment of a human biobank. The present study found that more than half (58-86%) of such established LCLs had transport times of less than 48 h, cell densities exceeding 10(6) cells/ml and cell viabilities greater than 90%. After EBV infection, 3306 freshly isolated lymphocytes required 30.0 +/- 0.1 days to become LCLs. Conversely, 1210 cryopreserved lymphocytes required 36.2 +/- 0.4 days. Cell density and viability of the culture affected transformation time in freshly isolated lymphocytes. On the other hand, blood transport time, cryopreservation time and initial cell viability were major factors in cryopreserved specimens. These results contribute to general information concerning the establishment of a human biobank for EBV infected cells.
Asunto(s)
Linfocitos B/citología , Linfocitos B/virología , Transformación Celular Viral , Herpesvirus Humano 4 , Animales , Callithrix , Recuento de Células , Línea Celular Transformada/citología , Línea Celular Transformada/virología , Separación Celular , Supervivencia Celular , Criopreservación , HumanosRESUMEN
BACKGROUND: Chest computed tomography (CT) as a primary screening method in candidates for living donor liver transplantation (LDLT) is not yet a standardized procedure. The aim of this study is to present our methods and result of evaluation of pulmonary small nodules (PSN) after CT as a primary screening tool. PATIENTS AND METHODS: A total of 360 primary adult LDLTs were performed between October 2009 and December 2012. The 37 candidates with PSNs found on CT were divided into two groups, with 23 patients in the group that was chest radiography (CXR) positive (+) and 14 in the group that was CXR negative (-). RESULTS: The nodular size in the CXR (-) group was significantly smaller than in the CXR (+) group (3.86 ± 1.24 vs 7.56 ± 4.08, P = .004). The sensitivity of CT for PSN was 37/360 (10.28%), much higher than the 14/360 (3.89%) for CXR alone. A total of 27 patients underwent video-assisted thoracoscopic surgery for pathologic diagnosis, and 10 were diagnosed as having benign PSNs by stationary sizes on serial CT scans. In the CXR (-) group, there were 2 cases of malignancy, 3 tuberculosis (TB), 3 Cryptococcus, and 15 other benign PS. In the CXR (+) group, there were 1 malignancy, 3 TB, 4 Cryptococcus, and other 6 benign PSNs. Recurrent infection was not seen in the posttransplantation follow-up of 13 candidates with infections. Excluding the 3 malignant PSNs, the 34 candidates in both groups survived 100% for more than 2 years after LDLT. CONCLUSION: To exclude malignancy and to diagnose infectious PSN for further treatment in a timely manner, chest CT should be used as the primary screening tool for asymptomatic candidates for LDLT.
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Trasplante de Hígado/métodos , Nódulos Pulmonares Múltiples/diagnóstico por imagen , Diagnóstico Precoz , Femenino , Humanos , Donadores Vivos , Enfermedades Pulmonares , Masculino , Persona de Mediana Edad , Nódulos Pulmonares Múltiples/patología , Cuidados Preoperatorios/métodos , Tomografía Computarizada por Rayos X/métodosRESUMEN
Bringing ultracold atomic gases into the quantum Hall regime is challenging. We engineered an effective magnetic field in a two-dimensional lattice with an elongated-strip geometry, consisting of the sites of an optical lattice in the long direction and of three internal atomic spin states in the short direction. We imaged the localized states of atomic Bose-Einstein condensates in this strip; via excitation dynamics, we further observed both the skipping orbits of excited atoms traveling down the system's edges, analogous to edge magnetoplasmons in two-dimensional electron systems, and a dynamical Hall effect for bulk excitations. Our technique involves minimal heating, which will be important for spectroscopic measurements of the Hofstadter butterfly and realizations of Laughlin's charge pump.
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BACKGROUND: Empyema frequently complicates the hospitalization of children; and in advanced stages, it often requires surgical intervention. In this study, we investigated the use of video-assisted thoracic surgery (VATS) for the management of postpneumonic empyema in children who have had an unsatisfactory medical response. METHODS: We did a retrospective review of the medical records of 51 consecutive patients with loculated empyema (mean age, 5 years; range, 2 months to 15 years) hospitalized at Chang Gung Memorial Hospital between 1995 and 2000. All patients underwent debridement of the necrotic lung tissue and evacuation of the loculated empyema cavity using a VATS approach. RESULTS: The mean operating time for the 51 patients was 90 min (range, 50-210); mean blood loss was 70 cc. Fever subsided within 72 h postoperatively in all patients. On average, chest tubing was removed on the 7th postoperative day (range, 4-18 days). However, in one patient who suffered from a prolonged air leak, the chest tube was not removed until day 18. The mean postoperative stay for all patients was 13.7 days (range, 9-23). No deaths occurred, and all of the children made a good recovery. A follow-up revealed that one of the 51 children patient suffered a left upper lung abscess 7 months after discharge. Left upper lobectomy was performed in this case, and the patient was discharged uneventfully 10 days after the operation. CONCLUSIONS: VATS is a safe and effective treatment for pediatric empyema. Thoracoscopic-assisted surgery facilitates visualization, evacuation, and debridement of the necrotizing lung tissue. Early surgical intervention can avoid lengthy hospitalization and prolonged intravenous antibiotic therapy, and it can accelerate clinical recovery.
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Empiema Pleural/etiología , Empiema Pleural/cirugía , Neumonía Bacteriana/complicaciones , Cirugía Torácica Asistida por Video/métodos , Adolescente , Pérdida de Sangre Quirúrgica , Niño , Preescolar , Empiema Pleural/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Humanos , Lactante , Tiempo de Internación , Absceso Pulmonar/etiología , Masculino , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Factores de Tiempo , Insuficiencia del TratamientoRESUMEN
BACKGROUND: Incisional recurrence after thoracoscopic surgery has been reported infrequently. In recent years, several reports of port-site recurrence after laparoscopic oncologic procedures have been published. This study evaluates the incidence of incisional recurrence among patients with intrathoracic malignancy after diagnostic and therapeutic thoracoscopy. METHODS: The medical records of all patients with intrathoracic malignancies who underwent thoracoscopic procedures between 1992 and 1998 at Chang Gung Memorial Hospital Linkou Medical Center were reviewed. Information includes preoperative tumor status, thoracoscopic findings, primary tumor location, tumor pathology, procedures performed, and perioperative complications were recorded. RESULTS: A total of 1,069 patients with known intrathoracic malignancies underwent thoracoscopy. The mean follow-up time was 17.1 months (range, 1-68 months). Two recurrences at the incision were identified (0.19%). Both patients with incision-site recurrence had advanced intrathoracic disease at the time of thoracoscopy. The one patient had a malignant pleural effusion (T4), and the other had diffuse pleural metastasis. CONCLUSION: The incidence of incisional recurrence after thoracoscopic oncologic surgery is very low. When recurrence occurs at the incision, it is associated most commonly with advanced intrathoracic disease. Additional patients and a longer follow-up evaluation are required, however, to confirm this observation.