64,657 research outputs found
Development of an enzyme-linked immunosorbent assay, using a monoclonal antibody against a2-macroglobulin, for the diagnosis of systemic lupus erythematosus
No full textOBJECTIVES: To develop an enzyme-linked immunosorbent assay (ELISA) using a
monoclonal antibody (mab) directed against abnormally glycosylated serum
alpha2-macroglobulin (alpha2-M) from patients with systemic lupus erythematosus
(SLE).
DESIGN AND METHODS: Serum alpha2-M purified by HPLC from patients with SLE was
injected in a Balb/c, CB6 F1 female mouse and hybrid cell lines were screened
using alpha2-M Glu-C fragments derived from SLE and normal donors (NHS). A mab
was selected and used to develop an ELISA by which sera from NHS (n = 14), SLE (n
= 34), rheumatoid arthritis (n = 15), Sjögren's syndrome (n = 11), mixed
connective tissue diseases (n = 12), and liver diseases (n = 11) were analyzed.
RESULTS: The affinity of the mab for alpha2-M from SLE, but not from the other
diseases, was higher compared to NHS, as demonstrated by immunoblotting and
ELISA.
CONCLUSIONS: The ELISA was capable of recognizing changes of glycosylation of
alpha2-M in SLE and may be useful for its differential diagnosis
Validity of the Novel Taiwan Lymphoscintigraphy Staging and Correlation of Cheng Lymphedema Grading for Unilateral Extremity Lymphedema
No full textOBJECTIVE: The aim was to validate the new Taiwan Lymphoscintigraphy Staging, correlate it with Cheng Lymphedema Grading (CLG) and evaluate the treatment outcomes of unilateral extremity lymphedema. BACKGROUND: No consensus has been reached for diagnosis and staging for patients with lymphedema among medical specialties. METHODS: We included 285 patients with unilateral extremity lymphedema using lymphoscintigraphy. Lymphoscintigraphy was correlated to clinical symptoms and signs, and classified into normal lymphatic drainage, partial obstruction, and total obstruction. Inter- and intraobserver reliability of Taiwan Lymphoscintigraphy Staging, correlation between Taiwan Lymphoscintigraphy Staging and clinical findings were conducted. Patients were categorized in "surgical" (n = 154) or "nonsurgical" (n = 131) groups for outcome evaluation. RESULTS: Lymphoscintigraphy found 11 patients (3.9%) with normal lymphatic drainage, 128 (44.9%) with partial obstruction, and 146 (51.2%) with total obstruction. Taiwan Lymphoscintigraphy Staging showed high interobserver agreement [intraclass correlation coefficient: 0.89 (95% confidence interval, 0.82-0.94)], and significantly correlated to computed tomography volumetric difference (r = 0.66, P < 0.001) and CLG [intraclass correlation coefficient: 0.79 (95% confidence interval 0.72-0.84)]. At a mean follow-up of 31.2 ± 2.9 months, significant improvement in the circumferential difference (from 23.9% ± 17.6% to 14.6% ± 11.1%; P = 0.03) with a mean circumferential reduction rate of 40.4% ± 4.5% was found in surgical group. At a mean follow-up of 26.6 ± 8.7 months, the nonsurgical group had increase of mean circumferential difference from 24.0% ± 17.2% to 25.3% ± 19.0% (P = 0.09), with a mean circumferential reduction rate was -1.9% ± 13.0%. CONCLUSIONS: The Taiwan Lymphoscintigraphy Staging is a reliable diagnostic tool, correlated with clinical findings and CLG, aiding in the selection of the appropriate treatment to achieve favorable long-term outcomes in unilateral extremity lymphedema
Insight into atomically dispersed porous M-N-C single-site catalysts for electrochemical CO2 reduction
No full textTransition metal single-site catalysts have unique activities for electrochemical CO2 reduction. However, the exact active center and reaction mechanism remain unclear due to a number of challenges in the controllable synthesis of single-atom catalysts (SACs) and defects in metal supports. Here we combine both experimental and theoretical calculations to systematically explore the mechanistic reaction path of selected transition metal single sites on nitrogen-doped porous carbon. Facile pyrolysis was employed to prepare a fullerene type carbon with 0.35 nm interlayer distances to support the family of M-N-C (M = Ni, Fe, Co and Cu). Experimentally, Ni and Fe outperform the other metals with high faradaic efficiency up to >97% and 86.8%, respectively. The theoretical calculations reveal that Ni-N-C exhibits optimum activity for CO2 reduction to CO at a higher overpotential because of the moderate *CO binding energy at the Ni site, which accommodates *COOH formation and *CO desorption. Furthermore, the strong binding energy of *CO on the Fe site enables the catalyst to reduce CO2 beyond CO. A remarkable current density of 17.6 mA cm-2 has been achieved with the Ni-N-C catalyst and a record of 5.74 s-1 TOF has been realized at -0.8 V vs. RHE for the Ni-N-C catalyst.No Full Tex
Inversion For Permeability From Stoneley Wave Velocity And Attenuation
No full textThe in situ permeability of a formation is obtained by the inversion of Stoneley wave
phase velocity and attenuation, which are evaluated by applying the Extended Prony's
method to the array sonic logging data. The Maximum Likelihood inversion is used
together with logarithmic parameterization of the permeabilities. Formation shear
wave velocity is also inverted for. This process is tested on both synthetic and field
data. Logarithmic parameterization contributes to rapid convergence of the algorithm.
Permeabilities estimated from field data are in good agreement with core measurements.Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortiu
Fourth-Order Finite Difference Acoustic Logs In A Transversely Isotropic Formation
No full textIn this paper we present a finite difference scheme for seismic wave propagation in
a fluid-filled borehole in a transversely isotropic formation. The first-order hyperbolic
differential equations are approximated explicitly on a staggered grid using an algorithm
that is fourth-order accurate in space and second-order accurate in time. The grid
dispersion and grid anisotropy are analyzed. Grid dispersion and anisotropy are well
suppressed by a grid size of 10 points per wavelength. The stability condition is also
obtained from the dispersion analysis. This finite difference scheme is implemented
on the nCUBE2 parallel computer with a grid decomposition algorithm. The finite
difference synthetic waveforms are compared with those generated using the discrete
wavenumber method. They are in good agreement. The damping layers effectively
absorbed the boundary reflections. Four vertically heterogeneous borehole models: a
horizontal layered formation, a borehole with a radius change, a semi-infinite borehole,
and a semi-infinite borehole with a layer, are studied using the finite difference method. Snapshots from the finite difference results provide pictures of the radiating wavefields.Massachusetts Institute of Technology. Borehole Acoustics and Logging Consortiu
Energy Partitioning and Attenuation of Guided Waves in a Radially Layered Borehole
No full textRecently published results (Tubman et al., 1984; Baker,. 1984) indicate that
synthetic full waveform acoustic logs generated in cased or damaged boreholes
differ significantly from those generated in an open hole with the same formation
parameters. In particular, the guided waves appear to be the most affected by such
radial layering. In order to gain some understanding of these effects, the amplitude
response and energy distribution of the pseudo-Rayleigh and Stoneley waves are
studied for the cased and invaded borehole models. The expressions derived by
Cheng et al. (1 982) are used to calculate partition coefficients (partial derivatives
of phase velocity with respect to body wave velocities) for the guided wave modes.
The attenuation of the guided wave can then be represented by the sum of the layer
attenuation values weighted by their respective partition coefficients. The results
indicate that the attenuation of the Stoneley wave is dominated by the fluid
attenuation at all frequencies in fast formations, both in the open hole geometry and
in the presence of casing or invaded zones. In a slow formation, the Stoneley wave
attenuation becomes more sensitive to the shear wave attenuation of the formation
at higher frequencies in both the open and cased hole situations. For the pseudo-Rayleigh
wave, the introduction of casing reduces the effect of the fluid attenuation,
while the presence of an invaded zone reduces the effect of the formation shear
attenuation. Plots of the partition coefficients indicate that the casing and invasion
layers are most important over a limited frequency range which is related to the
thickness of the layer. Radial displacement curves illustrate the depth of penetration
of the various frequency components of the pseudo-Rayleigh wave.Massachusetts Institute of Technology. Full Waveform Acoustic Logging Consortiu
Acoustic Logging In Randomly Stratified Formations
No full textThe propagation of borehole acoustic waves in the presence of various types of heterogeneous formations is investigated by modeling them as stratified media with varying velocity-depth distributions. Two types of formations are modeled, using translational and cyclic random models, respectively. Borehole acoustic wavefields for the heterogeneity formation models are simulated using finite-difference techniques. The wavefield modeling results show that the borehole acoustic waves can be significantly affected by the formation heterogeneities. Specifically, the scattering due to heterogeneity can cause significant amplitude attenuation and travel time delay for the transmitted waves. The borehole guided waves are also sensitive to the formation heterogeneity. The effects of the random formation heterogeneity on the borehole acoustic waves are controlled by two factors: the degree of heterogeneity variation and the heterogeneity scale length relative to the wavelength.Massachusetts Institute of Technology. Borehole Acoustics and Logging Consortiu
Cheilosia distincta Barkalov & Cheng 1998
No full textCheilosia distincta Barkalov & Cheng, 1998 Figs 15–16 Cheilosia (Montanocheila) distincta Barkalov & Cheng, 1998: 313. Type locality: China: Sichuan: Xiangcheng (holotype, ♂, ZICAS). Cheilosia (Montanocheila) distincta – Barkalov & Cheng 2004: 297. Differential diagnosis Cheilosia (M.) distincta is among the Nepalese species closest to C. (M.) erratica. Cheilosia erratica differs by having tergite III entirely yellowish pilose, while C. distincta has tergite III black pilose. Material examined NEPAL • 1 ♂; Solukhumbu, Shibuche; 27°34′ N, 86°46′ E; 2700– 2300 m a.s.l.; 18 May 1997; M. Hauser leg. [524]; CSCA • 1 ♀; Ramechap Mohabir Khola E of Shivalaya; 2500–2600 m a.s.l.; 27°35′ N, 86°19′ E; 6–7 May 97; Hauser leg.; CSCA • 1 ♀; Westnepal, Distr. Humla, Simikot, 12 km S of Raya; 29°52′29″ N, 81°51′57″ E; 2400 m a.s.l.; 8 Jul. 2001; F. Creutzburg leg.; IBSJW / NME • 3 ♀♀; Kathmandu S, Phulchoki; 27°35′09″ N, 85°22′50″ E; ca 1800 m a.s.l.; 18 Jul. 2001; F. Creutzburg leg.; IBSJW / NME • 1 ♀; Prov. Karnali, Gothigaon, Flussufer; 29°14.55′ N, 82°18.48′ E; 2600 m a.s.l.; 14 Jun. 1997; J. Weipert leg.; IBSJW / NME. Taxonomic remark The description of Cheilosia (M.) distincta Barkalov & Cheng, 1998 agrees with the description of Cheilosia hirticincta Brunetti, 1915 in almost all described characteristics. The studied specimens from Nepal, one male and six females, have basoflagellomere reddish-brown with light greyish dusting and blackish dorsal margin (described as black with greyish dusting in Cheilosia distincta and C. hirticincta). The NHM (London) has six male specimens identified as Cheilosia hirticincta Brunetti. The structure of the male genitalia of Cheilosia (M.) distincta and C. hirticincta is very similar. However, we have not been able to locate and study the type material of C. hirticincta to evaluate a possible synonymy of C. distincta. Distribution China, Nepal.Published as part of Barkalov, Anatolij V. & Ståhls, Gunilla, 2022, Cheilosia (Diptera, Syrphidae: Rhingiini) of Nepal with descriptions of 29 new species, pp. 1-127 in European Journal of Taxonomy 829 (1) on pages 34-37, DOI: 10.5852/ejt.2022.829.1863, http://zenodo.org/record/683993
Estimating A Shear Modulus Of A Transversely Isotropic Formation
No full textA method to estimate c[subscript 66], which is a shear modulus of a transversely isotropic formation (with its symmetry axis parallel to the borehole), is developed and tested. The inversion for c[subscript 66] is based upon a cost function which has three terms: a measure of the misfit between the observed and predicted wavenumbers, a measure of the misfit between the current estimate for c[subscript 66] and the initial guess of its value, and penalty functions which constrain the estimate for c[subscript 66] to physically acceptable values. The inversion is applied to synthetic data for fast and slow formations, and the estimates for c[subscript 66] are within 5% of their correct values and are well resolved. The inversion is applied to field data from a formation which consists mostly of siltstone. All estimates for c[subscript 66] are significantly higher than for c[subscript 44] , and the S-wave anisotropy generally ranges from 19 to 24%.Massachusetts Institute of Technology. Full Waveform Acoustic Logging ConsortiumPhillips Petroleum Fellowshi
Measurements Of Shear-Wave Azimuthal Anisotropy With Cross-Dipole Logs
No full textThree methods for analyzing azimuthal anisotropy from cross-dipole logs are applied
to data from the Powder River Basin in Wyoming. These techniques are based on
the phenomena of flexural wave splitting in anisotropic materials and are analogous to
the techniques used for VSP data processing. The four-component cross-dipole logging
data obtained with a Schumberger tool from a vertically-fractured section of 56 m at a
depth of 3550 m are processed with three different techniques. The results demonstrate
that the non-orthogonal rotation method works best for the data. The results from
the linear transform and polar energy spectrum methods are acceptable. The linear
transform processing takes much less computing time, while the polar energy spectrum
method is computationally-intensive.Massachusetts Institute of Technology. Borehole Acoustics and Logging ConsortiumERL/nCUBE Geophysical Center for Parallel ProcessingUnited States. Dept. of Energy (Contract DE-FG02-86ER13636
- …
