1,407 research outputs found
Lymphocyte Defect in Plasmacytoma-bearing Mice
Multiple myeloma is often associated with humoral immunodepression in both man and mouse. When mice bearing the humorally immunodepressive plasmacytomas TEPC-183 and SPQC-11 were injected with SRBC, the rise of serum haemolysins was significantly less than that of non-tumour-bearing mice. Mice with the plasmacytomas MPC-11 and MOPC-315 have an antibody response similar to normal mice when injected with SRBC. Following immunization, normal mice and those bearing MPC-11 showed a 2- to 3-fold increase in total spleen lymphocytes. Mice bearing TEPC-183 or SPQC-11, the plasmacytomas causing an impaired antibody response, has significant increase in spleen lymphocytes under the same conditions. Mice bearing MOPC-315 had a very high initial count of spleen lymphocytes, which did not further increase upon immune stimulation
Unraveling the "Pressure-Effect" in Nucleation
The influence of the pressure of a chemically inert carrier-gas on the
nucleation rate is one of the biggest puzzles in the research of gas-liquid
nucleation. Different experiments can show a positive effect, a negative
effect, or no effect at all. The same experiment may show both trends for the
same substance depending on temperature, or for different substances at the
same temperature. We show how this ambiguous effect naturally arises from the
competition of two contributions: nonisothermal effects and pressure-volume
work. Our model clarifies seemingly contradictory experimental results and
quantifies the variation of the nucleation ability of a substance in the
presence of an ambient gas. Our findings are corroborated by results from
molecular dynamics simulation and might have important implications since
nucleation in experiments, technical applications, and nature practically
always occurs in the presence of an ambient gas.Comment: 4 pages, 3 figures. v2: All citations now appear correctly. v3:
Updated one point in Fig.
Increased susceptibility to proactive interference in adults with dyslexia?
Recent findings show that people with dyslexia have an impairment in serial-order memory. Based on these findings, the present study aimed to test the hypothesis that people with dyslexia have difficulties dealing with proactive interference (PI) in recognition memory. A group of 25 adults with dyslexia and a group of matched controls were subjected to a 2-back recognition task, which required participants to indicate whether an item (mis)matched the item that had been presented 2 trials before. PI was elicited using lure trials in which the item matched the item in the 3-back position instead of the targeted 2-back position. Our results demonstrate that the introduction of lure trials affected 2-back recognition performance more severely in the dyslexic group than in the control group, suggesting greater difficulty in resisting PI in dyslexia.Peer reviewedFinal Accepted Versio
An accurate description of quantum size effects in InP nanocrystallites over a wide range of sizes
We obtain an effective parametrization of the bulk electronic structure of
InP within the Tight Binding scheme. Using these parameters, we calculate the
electronic structure of InP clusters with the size ranging upto 7.5 nm. The
calculated variations in the electronic structure as a function of the cluster
size is found to be in excellent agreement with experimental results over the
entire range of sizes, establishing the effectiveness and transferability of
the obtained parameter strengths.Comment: 9 pages, 3 figures, pdf file available at
http://sscu.iisc.ernet.in/~sampan/publications.htm
Magnetic phase transition in V2O3 nanocrystals
V2O3 nanocrystals can be synthesized through hydrothermal reduction of
VO(OH)2 using hydrazine as a reducing agent. Addition of different ligands to
the reaction produces nanoparticles, nanorods and nanoplatelets of different
sizes. Small nanoparticles synthesized in this manner show suppression of the
magnetic phase transition to lower temperatures. Using muon spin relaxation
spectroscopy and synchrotron x-ray diffraction, it is determined that the
volume fraction of the high-temperature phase, characterized by a rhombohedral
structure and paramagnetism, gradually declines with decreasing temperature, in
contrast to the sharp transition observed in bulk V2O3.Comment: 6 pages, 6 figure
Residential radon-222 exposure and lung cancer: exposure assessment methodology
Although occupational epidemiological studies and animal experimentation provide strong evidence that radon-222 (222Rn) progeny exposure causes lung cancer, residential epidemiological studies have not confirmed this association. Past residential epidemiological studies have yielded contradictory findings. Exposure misclassification has seriously compromised the ability of these studies to detect whether an association exists between 222Rn exposure and lung cancer. Misclassification of 222Rn exposure has arisen primarily from: 1) detector measurement error; 2) failure to consider temporal and spatial 222Rn variations within a home; 3) missing data from previously occupied homes that currently are inaccessible; 4) failure to link 222Rn concentrations with subject mobility; and 5) measuring 222Rn gas concentration as a surrogate for 222Rn progeny exposure. This paper examines these methodological dosimetry problems and addresses how we are accounting for them in an ongoing, population-based, case-control study of 222Rn and lung cancer in Iowa
Evolution of the electronic structure with size in II-VI semiconductor nanocrystals
In order to provide a quantitatively accurate description of the band gap
variation with sizes in various II-VI semiconductor nanocrystals, we make use
of the recently reported tight-binding parametrization of the corresponding
bulk systems. Using the same tight-binding scheme and parameters, we calculate
the electronic structure of II-VI nanocrystals in real space with sizes ranging
between 5 and 80 {\AA} in diameter. A comparison with available experimental
results from the literature shows an excellent agreement over the entire range
of sizes.Comment: 17 pages, 4 figures, accepted in Phys. Rev.
Influence of Grain Size on the Band-gap of Annealed SnS Thin Films
The manuscript reports the variation in optical band-gap of vacuum annealed
SnS thin films. The samples were characterized by using X-Ray Diffraction,
UV-visible Spectroscopy and Raman Analysis. Results show that while annealing
does not effect the nano-crystalline sample's lattice structure or unit cell
size it does control the grain size. The band-gap (Eg) decreases with increase
in grain size. Eg values were found to be very high (1.8-2.5 eV) for samples
studied
Work participation, social roles, and empowerment of Q-fever fatigue syndrome patients ≥10 years after infection
Objective:To determine work participation, social roles, and empowerment of QFS patients ≥10-year after infection. Methods:QFS patients ≥10-year after acute infection, who were of working age, participated in a cross-sectional survey study. Work participation, fulfilment of social roles, and empowerment outcomes were studied for the total population, as well as for subgroups based on employment type and current work status. Associations between empowerment, work and social roles were examined. Results:291 participants were included. Of the 250 participants who had paid work before Q-fever, 80.4% stopped working or worked less hours due to QFS. For each social role, more than half of the participants (56.6–87.8%) spent less time on the role compared to before Q-fever. The median empowerment score was 41.0 (IQR: 37.0–44.0) out of 60. A higher empowerment score was significantly associated with lower odds of performing all social roles less due to QFS (OR = 0.871–0.933; p<0.001–0.026), except for parenting and informal care provision (p = 0.070–0.460). No associations were found between empowerment and current work status. Conclusion: Work participation and fulfilment of social roles is generally low in QFS patients. Many of the participants stopped working or are working less hours due to QFS, and most spent less time on social roles compared to before Q-fever. Minor variation was seen in total empowerment scores of participants; however, these slight differences were associated with the fulfilment of social roles, but not work participation. This new insight should be further explored in future studies.</p
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