Search Results - (Author, Cooperation:K. J. Liu)

2012-03-24

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Cell Lineage ; Cell Proliferation ; Chick Embryo ; Dendritic Cells/*cytology/physiology ; Embryo, Mammalian/cytology ; Gene Deletion ; Gene Expression Regulation, Developmental ; Genes, myb ; Hematopoietic Stem Cells/*cytology/physiology ; Kupffer Cells/cytology/physiology ; Langerhans Cells/cytology/physiology ; Liver/embryology ; Macrophages/*cytology/physiology ; Mice ; Microglia/cytology/physiology ; Myeloid Cells/*cytology/physiology ; *Myelopoiesis ; Proto-Oncogene Proteins/genetics/metabolism ; Proto-Oncogene Proteins c-myb/*metabolism ; Trans-Activators/genetics/metabolism ; Yolk Sac/*cytology

2018-03-06

Hindawi

1687-5966

1687-5974

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

1248-9204

Gastroesophageal Reflux ; Achalasia ; Esophageal Manometry ; Fundoplication

Springer Online Journal Archives 1860-2000

Medicine

Summary When evaluating foregut symptoms which may originate from many sites, accurate diagnosis must be achieved by cost-effective and efficient diagnostic methods. Since all tests cannot be done routinely, invasive tests are mandatory only when the diagnosis is uncertain; testing which confirms the obvious is overly expensive and superfluous. This report describes “selective” preoperative diagnostic testing for patients with heartburn and dysphagia; endoscopy was used always, but radiography, manometry, and pH testing were done selectively. Hiatus hernia remains an elusive entity which resists easy definition. Methods: A total of 273 patients operations (185 with gastroesophageal reflux disease (GERD) and 88 with achalasia (ACHA) of the esophagus) were operated upon during a 15 year period. All heartburn patients had endoscopy; if erosive esophagitis was present and symptoms responded to medical treatment the diagnosis of GERD was made; manometry and pH studies were performed selectively. Esophagrams or other special X-Rays (spiral tomography) were performed often, but selectively, in preoperative patients and less commonly in postoperative patients. When indicated, fundoplication was performed for GERD and transabdominal cardiomyotomy with fundoplication for ACHA. Results (Tables 1, 2): Endoscopy was performed in all patients. Motility examinations (n = 248) and pH studies (n = 175) were helpful in defining operative candidates; 95% of GERD and ACHA operations were effective, and postoperative hiatus hernia or wrap disruption occurred rarely (2%). ACHA patients had minimal reflux, and one had reoperation for extrinsic stricture at the gastoesophageal junction. Unexpected hiatus hernia was found in 8–10% of both groups. Conclusions: Clinical judgment supported by selective diagnostic testing in GERD and ACHA effectively identified operative candidates. The role of hiatus hernia in causing symptoms in individual patients is largely unknown at present; further, there is no reliable noninvasive way of estimating the size of hernia in a single patient.

Electronic Resource

1573-109X

Springer Online Journal Archives 1860-2000

Electrical Engineering, Measurement and Control Technology

Abstract We propose a new class ofhyperbolic Gram-Schmidt methods to simultaneously update and downdate the Cholesky factor of a sample covariance matrix efficiently with applications to sliding window recursive least squares (RLS) filtering problems. Several vectorized versions of this Gram-Schmidt approach are introduced, which include conventional column-updating, modified row/column-updating, and square-root-free methods. Comparisons to the existing known methods, such as Householder transformation and Givens rotation, are also given. Upon further reformulating these algorithms, a systolic triarray structure is proposed to facilitate VLSI implementations.

Electronic Resource

1573-109X

Springer Online Journal Archives 1860-2000

Electrical Engineering, Measurement and Control Technology

Abstract The Householder transformation is considered to be desirable among various unitary transformations due to its superior computational efficiency and robust numerical stability. Specifically, the Householder transformation outperforms the Givens rotation and the modified Gram-Schmidt methods in numerical stability under finite-precision implementations, as well as requiring fewer arithmetical operations. Consequently, the QR decomposition based on the Householder transformation is promising for VLSI implementation and real-time high throughput modern signal processing. In this paper, a recursive complex Householder transformation (CHT) with a fast initialization algorithm is proposed and its associated parallel/pipelined architecture is also considered. Then, a CHT based recursive least-squares algorithm with a fast initialization is presented. Its associated systolic array processing architecture is also considered.

Electronic Resource