Analytic gradient routines are a desirable feature for quantum mechanical methods, allowing for efficient determination of equilibrium and transition state structures and several other molecular ...properties. In this work, we present analytical gradients for multiconfiguration pair-density functional theory (MC-PDFT) when used with a state-specific complete active space self-consistent field reference wave function. Our approach constructs a Lagrangian that is variational in all wave function parameters. We find that MC-PDFT locates equilibrium geometries for several small- to medium-sized organic molecules that are similar to those located by complete active space second-order perturbation theory but that are obtained with decreased computational cost.
: The activation associated proteins CD23 and CD69 are expressed on cells of different lineages upon mitogenic stimulation. CD23 is a well characterized multifunctional protein in lymphocyte ...development recognized as a diagnostic marker for chronic lymphocytic leukaemia. CD69 is one of the earliest markers expressed after activation of T cells, but its function is unclear. The aim of this study was to investigate the expression of these antigens in B‐cell non‐Hodgkin's lymphomas (NHL) in relation to clinical behaviour. Ninety samples from 84 patients with NHL of B cell type were studied for the expression of CD23 and CD69 in CD20+ B cells by flow cytometric dual parameter analysis. In individual lymphomas the CD23 and CD69 antigens showed an “on or off” pattern with most or very few cells positive for each antigen. The CD23 antigen was expressed in 23 of 53 (43%) indolent lymphomas and in 2 of 37 (5%) aggressive cases. Most indolent lymphomas (81%) and about half the aggressive cases (53%) expressed the CD69 antigen. Thus, both markers were associated with indolent type. CD23 expression correlated with chronic lymphocytic leukaemia subtype and CD69 expression with male gender, advanced stage, newly diagnosed lymphoma and shorter survival.
A proton beam of about 1 μm allows the study of inner structures of cells. These studies demand sophisticated preparation methods, not to destroy the morphology or the elemental distribution. ...Analysing a well-preserved cell may lead to important knowledge about basic regulatory processes at the cellular level. Freezing followed by removal of water by drying or by substitution with an organic solvent will be exemplified. Insulin-producing cells were studied to reach a further understanding of the signal transduction between stimulation to secrete insulin and the secretion.
In patients with primary hyperparathyroidism, measurements were made of basal and stimulated levels of intact parathyroid hormone (PTH). The basal PTH values were elevated in all but six of 89 ...patients and provided clear separation towards normal individuals (n = 75) and patients with hypercalcemia of other origin (n = 34). The PTH value correlated with the serum calcium concentration in hyperparathyroidism and with the weight of excised parathyroid adenomas but not with that of chief cell hyperplasias. A constant ethylenediaminetetraacetic acid infusion during 60 minutes of induced essentially linear reductions of plasma-ionized calcium concentrations, averaging 0.02 mmol/L/10 minutes, which were associated with swift, curvilinear, elevations of PTH levels that reached a plateau after 10 to 20 minutes. The increment in serum PTH level correlated with the basal PTH value both in patients with hyperparathyroidism and controls. However, in proportion to the much greater glandular mass in the patients with hyperparathyroidism, the secretion of PTH was relatively reduced. The findings support the value of the intact PTH assay in the differential diagnosis of hypercalcemia and show that PTH secretion in vivo is extremely sensitive to hypocalcemic stimulation, that the pathological parathyroid tissue in hyperparathyroidism is characterized by a reduction of hormone release per unit weight, and that the hormone secretion in hyperparathyroidism operates closer to its maximal capacity than under normal circumstances.
We have carried out a search for double Gamow-Teller excitations, employing the
24Mg(
18O,
18Ne)
24Ne reaction at 100 and 76 MeV/nucleon at NSCL-MSU and GANIL, respectively. The cross sections for ...low-lying excitations are typically a few nb/sr, providing evidence for a strong suppression of double Gamow-Teller excitations in heavy-ion double charge exchange, compared to pion-induced reactions. This result does not give good hope that heavy ions at intermediate energies could be used to probe double Gamow-Teller strength.
The topography of the peptidergic neuronal subpopulations in the guinea pig celiac-superior mesenteric ganglion was studied analyzing the distribution of immunoreactivity to neuropeptide Y (NPY), ...somatostatin (SOM), and vasoactive intestinal polypeptide (VIP)/polypeptide HI (PHI). For comparison, the ganglion was also studied using antisera against the 2 catecholamine-synthesizing enzymes tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH). Approximately 65% of the neuronal cell bodies contained NPY-like immunoreactivity (NPY-LI), whereas 25% of the principal ganglion cells contained SOM-like immunoreactivity (SOM-LI). Though occasional cells were found to contain both NPY-LI and SOM-LI, these peptides had a complementary distribution in the ganglion, with NPY cells in the celiac poles and SOM cells in the superior mesenteric pole. The vast majority of both the NPY- and SOM-positive cells also contained TH-like immunoreactivity (TH-LI), confirming their catecholaminergic, presumably noradrenergic, nature. Some noradrenergic neurons seemed to lack NPY- and SOM-LI. Small numbers of VIP/PHI-containing cell bodies were found in areas where the NPY-immunoreactive neurons predominated. Many of the VIP/PHI-positive cells contained NPY-LI and occasionally also TH-LI. The immunohistochemical markers were also observed in fibers. Thus, a comparatively weak NPY-LI was seen in smooth fibers, probably representing axons and axon bundles. SOM-LI was seen in a similar type of fiber but also in more strongly fluorescent fibers with a varicose appearance. The latter fibers were observed only in the SOM-dominated part of the ganglion, often surrounding the ganglion cells. Varicose fibers with a similar distribution containing DBH-like immunoreactivity (DBH-LI) were also seen. In addition, DBH- and TH-LI were seen in smooth axonlike processes. VIP-positive fibers exhibited a very dense fiber network, almost exclusively related to the SOM cell-dominated part of the ganglion. The projection of the postganglionic sympathetic neurons was studied with special reference to the pylorus using a combination of retrograde axonal tracing and indirect immunofluorescence techniques. Seventy-two hours after injection of the fluorescent tracer Fast Blue into the pyloric sphincter, labeled neurons were found in the ganglion. By comparing the Fast Blue-labeled cells with the immunoreactive cell bodies, neurons containing both dye and NPY- or SOM-LI were observed. In elution-restaining experiments, it was established that the majority of these cells were also immunoreactive to TH, indicating that they produce noradrenaline.
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