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61.
62.
Blind source separation assumes that the acquired signal is composed of a weighted sum of a number of basic components corresponding
to a number of limited sources. This work poses the problem of ECG signal diagnosis in the form of a blind source separation
problem. In particular, a large number of ECG signals undergo two of the most commonly used blind source separation techniques,
namely, principal component analysis (PCA) and independent component analysis (ICA), so that the basic components underlying
this complex signal can be identified. Given that such techniques are sensitive to signal shift, a simple transformation is
used that computes the magnitude of the Fourier transformation of ECG signals. This allows the phase components corresponding
to such shifts to be removed. Using the magnitude of the projection of a given ECG signal onto these basic components as features,
it was shown that accurate arrhythmia detection and classification were possible. The proposed strategies were applied to
a large number of independent 3s intervals of ECG signals consisting of 320 training samples and 160 test samples from the
MIT-BIH database. The samples equally represent five different ECG signal types, including normal, ventricular couplet, ventricular
tachycardia, ventricular bigeminy and ventricular fibrillation. The intervals analysed were windowed using either a rectangular
or a Hamming window. The methods demonstrated a detection rate of sensitivity 98% at specificity of 100% using nearest neighbour
classification of features from ICA and a rectangular window. Lower classification rates were obtained using the same classifier
with features from either PCA or ICA and a rectangular window. The results demonstrate the potential of the new method for
clinical use. 相似文献
63.
Sam Tsemberis E. Sally Rogers Eleni Rodis Patricia Dushuttle Vicki Skryha 《Journal of community psychology》2003,31(6):581-590
Provision of residential services to people with mental illness has assumed increasing importance since deinstitutionalization and as community‐ based services have increased. This large‐scale multisite study of housing programs specifically for persons with mental illness examines one of the factors that lead to successful residential tenure for persons with serious mental illness. To date, the Lehman Quality of Life Scale has been used primarily to assess satisfaction with housing in studies of residential services. This article reports on a new measure of housing satisfaction. This new 25‐item instrument was developed, field tested in a variety of housing settings across the country, and analyzed for reliability and validity by a group of housing researchers and clinicians. The implications of using this instrument for future evaluation and research on housing for persons with mental illness are examined. © 2003 Wiley Periodicals, Inc. J Comm Psychol 31: 581–590, 2003. 相似文献
64.
Fine-needle aspiration (FNA) cytology and immunophenotyping by flow cytometry (FCM) are increasingly being used for diagnosing and subclassifying lymphoma in the REAL/WHO classification. Herein, we report a case of primary mediastinal large B-cell lymphoma (PMBL), a subtype of diffuse large B-cell lymphoma in the WHO classification, diagnosed by FNA cytology in conjunction with FCM. This, to our knowledge, has not previously been reported. A 57-yr-old woman presented with bilateral axillary lymphadenopathy and intermittent shortness of breath. CT scan revealed a 5-cm anterior mediastinal mass and mediastinal lymphadenopathy. Endoscopic ultrasound-guided FNA of a 4.5-cm subcarinal lymph node showed medium to large atypical lymphocytes with scant to moderate finely vacuolated cytoplasm. Nuclei were enlarged, cleaved, noncleaved, lobulated, and hyperchromatic. The background showed lymphoglandular bodies. Malignant large cell lymphoma was cytologically diagnosed. FCM, performed on a portion of the FNA specimen, demonstrated large B cells devoid of surface immunoglobulin expression, the characteristic immunophenotype of PMBL. The histologic diagnosis was PMBL. Touch-imprint cytology of the histologic specimen showed large cells with a narrow rim of clear cytoplasm and prominent outer cell border. Nuclear features were similar to the FNA specimen. In the presence of a mediastinal mass, FNA cytology in conjunction with FCM can effectively diagnose PMBL in the appropriate clinical setting. 相似文献
65.
Youssef AR Shen CR Lin CL Barker RN Elson CJ 《Clinical and experimental immunology》2005,139(1):84-89
New Zealand Black (NZB) mice spontaneously develop autoimmune haemolytic anaemia (AIHA). Here the effect of injecting NZB mice with plasmids encoding IL-4 (pIL-4) or IL-10 (pIL-10) on NZB disease was tested. Both constructs delayed the development of anaemia as judged by increased haematocrit values as compared with controls, but neither altered the IgG1 to IgG2 red blood cell (RBC) bound autoantibody levels. The increased haematocrit value was associated temporally with increased RBC bound IgG in NZB mice treated with pIL-10, but not pIL-4. By contrast, up-regulation of splenic macrophage FcgammaRIIb2 mRNA was associated temporally with increased haematocrit values in NZB mice given pIL-4. However, no such increase occurred in NZB mice that inhaled a peptide containing a dominant T-cell epitope, although this treatment is known to bias the autoimmune response towards Th2 and to reduce the severity of anaemia. It is considered that IL-4 treatment, in part, ameliorates NZB anaemia by increasing the expression of the inhibitory FcgammaRIIb2 and thereby reducing the capacity of splenic macrophages to phagocytose autoantibody coated RBC, but that this mechanism does not explain the beneficial effects of the inhaled peptide. 相似文献
66.
Sikkema DJ Ziembiec NA Jones TR Hildreth SW Madore DV Quataert SA 《Clinical and diagnostic laboratory immunology》2005,12(1):218-223
Weight-based assignments for immunoglobulin G1 (IgG1) and IgG2 subclass antibodies to Streptococcus pneumoniae capsular polysaccharides (PnPs) in antipneumococcal standard reference serum lot 89-S (lot 89-S), also known as lot 89-SF, have been determined for serotypes 1, 4, 5, 7F, 9V, and 18C. This extends the usefulness of lot 89-S beyond the IgG1 and IgG2 subclass assignments for serotypes 3, 6B, 14, 19F, and 23F made previously (A. Soininen, H. Kayhty, I. Seppala, and T. Wuorimaa, Clin. Diagn. Lab. Immunol. 5:561-566, 1998) to cover 11 major serotypes associated with the highest percentage of pneumococcal disease worldwide. A method of equivalence of absorbances in enzyme immunosorbent assays was used to determine the IgG1 and IgG2 antibody concentrations for the additional serotypes in lot 89-S, based on the subclass values previously assigned for PnPs serotypes 6B, 14, and 23F. This cross-standardization method assures consistency with previous antibody assignments in that reference serum. The newly assigned subclass values for serotype 9V, and previously assigned values for serotype 14, were used to quantitate PnPs antibodies in sera from adult and pediatric subjects immunized with a pneumococcal conjugate vaccine. There was a predominance of IgG1 anti-PnPs antibodies in pediatric sera and IgG2 anti-PnPs antibodies in the adult sera. The IgG1 and IgG2 subclass assignments for the 11 PnPs serotypes in antipneumococcal standard reference serum lot 89-S are useful for quantitating and characterizing immune responses to pneumococcal infection and vaccination regimens. 相似文献
67.
Summary The development ofEimeria dispersa Tyzzer, a parasite of bobwhite quail, in Madin-Darby bovine kidney cell cultures was investigated. Excysted sporozoites were inoculated into Leighton tubes containing cell monolayers on glass coverglasses and maintained in minimum essential medium supplemented with heat-inactivated fetal calf serum. Sporozoites became intracellular within 2 h. Sporozoite-shaped schizonts, schizonts with developing merozoites, and mature first-generation schizonts were seen 24 h postinoculation. Intracellular first-generation merozoites, second-generation trophozoites, and early second-generation schizonts containing two nuclei were first observed 72 h postinoculation. Second-generation schizonts containing developing merozoites as well as mature second-generation schizonts were first seen 96h postinoculation. Gametogony was not observed.DM
developing merozoite
- HN
host nucleus
- IM
intracellular merozoite
- M
merozoite
- N
nucleus
- R
refractile body
- RB
residual body
- V
parasitophorous vacuole 相似文献
68.
Effects of a Single Hit from the Alpha Hemolysin Produced by Escherichia coli on the Morphology of Sheep Erythrocytes 总被引:2,自引:6,他引:2 下载免费PDF全文
Scanning electron micrographs of sheep erythrocytes showed that attachment of the alpha hemolysin produced by Escherichia coli resulted in the formation of spherocytes, with 10 to 20 small projections spaced relatively evenly over the surface of the erythrocyte membrane. This shape change was induced within 5 min after treatment. If the hemolysin concentration was reduced to a level which would lyse only a fraction of the total erythrocytes, the affected cells were easily identified against a background of normal, unaffected cells. Unlike sodium lauryl sulfate and other amphipathic agents which enter cell membranes and increase their flexibility, low concentrations of hemolysin did not provide protection against hypotonic hemolysis. These findings indicate that the surface projections were not the result of membrane expansion caused by incorporation of hemolysin into the outer portion of the lipid bilayer. The ability of a given amount of hemolysin to release a constant amount of hemoglobin in the presence of increasing concentrations of red cells confirmed that a single hit is sufficient for lysis. These results suggest that a single hemolysin molecule can bind to a sheep erythrocyte and trigger internal reactions which result in the derangement of membrane integrity at multiple sites on the surface. Confirmation of one-hit kinetics indicates that measurement of E. coli hemolysin activity should be carried out at low ratios of hemolysin to erythrocyte to decrease the possibility of multiple hits on a single cell. 相似文献
69.
The distribution of a previously described repeated DNA sequence present as a 1.3-kb PstI fragment in the genome of the rice blast fungus Magnaporthe grisea was analysed by carrying out DNA fingerprint analysis of 36 isolates including rice, non-rice and laboratory strains. The
analysis of various higher-molecular-weight PstI fragments with homology to the 1.3-kb repeat revealed that these may arise predominantly from transposon insertions or point
mutations. Analysis of a 5.1-kb derivative revealed both a point mutation at a PstI site and an insertion of a putative transposable element which caused an increase in molecular weight from 1.3 to 5.1 kb.
Another repeat element of 1.4 kb was identified and found to exist in association with the 1.3-kb repeat. Both 1.3- and 1.4-kb
elements were found to be parts of MGR583 (Hamer et al. 1989), a LINE-like element. These elements were present in a high
copy number in all the rice and a majority of non-rice pathogens indicating that MGR583 is not a host-specific sequence as
reported earlier. Our results suggest that repeated DNA elements in M. grisea have amplified independently of one another and further indicate that different isolates of M. grisea may have evolved from several distinct lines of origin.
Received: 12 April / 12 November 1996 相似文献
70.
Doris Škorić‐Milosavljević Fleur V. Y. Tjong Julien Barc Ad P. C. M. Backx Sally‐Ann B. Clur Karin van Spaendonck‐Zwarts Roelof‐Jan Oostra Najim Lahrouchi Leander Beekman Regina Bökenkamp Daniela Q. C. M. Barge‐Schaapveld Barbara J. Mulder Elisabeth M. Lodder Connie R. Bezzina Alex V. Postma 《American journal of medical genetics. Part A》2019,179(9):1836-1845
The first human mutations in GATA6 were described in a cohort of patients with persistent truncus arteriosus, and the phenotypic spectrum has expanded since then. This study underscores the broad phenotypic spectrum by presenting two patients with de novo GATA6 mutations, both exhibiting complex cardiac defects, pancreatic, and other abnormalities. Furthermore, we provided a detailed overview of all published human genetic variation in/near GATA6 published to date and the associated phenotypes (n = 78). We conclude that the most common phenotypes associated with a mutation in GATA6 were structural cardiac and pancreatic abnormalities, with a penetrance of 87 and 60%, respectively. Other common malformations were gallbladder agenesis, congenital diaphragmatic hernia, and neurocognitive abnormalities, mostly developmental delay. Fifty‐eight percent of the mutations were de novo, and these patients more often had an anomaly of intracardiac connections, an anomaly of the great arteries, and hypothyroidism, compared with those with inherited mutations. Functional studies mostly support loss‐of‐function as the pathophysiological mechanism. In conclusion, GATA6 mutations give a wide range of phenotypic defects, most frequently malformations of the heart and pancreas. This highlights the importance of detailed clinical evaluation of identified carriers to evaluate their full phenotypic spectrum. 相似文献