Carbon nanotubes/carbon fabrics and their reinforced resin matrix composites were manufactured by chemical vapor deposition and molding method, respectively. Different catalytic reduction processes ...with different catalyst types and reduction temperatures had different effects on their morphology and properties. It was found by a series of characterization methods that the catalytic activity of the bimetallic catalyst was higher than that of the single metal, and the surface uniformity of CNTs catalyzed by Fe-Co was the best. When the reduction temperature reached the growth temperature, the uniformity of CNTs and the interlaminar shear strength of composites increased obviously. The influence mechanism of these parameters was discussed in depth, which provided a fundamental engineering basis for understanding of catalytic reduction process, optimizing of CNTs growth process and the application of high-performance composite materials.
Abstract Introduction Here we present the metallation, characterization, in vivo and in vitro evaluations of dual-targeting, peptide-based radiopharmaceuticals with utility for imaging and ...potentially treating prostate tumors by virtue of their ability to target the αV β3 integrin or the gastrin releasing peptide receptor (GRPr). Methods RGD-Glu-6Ahx-RM2 (RGD: Arg-Gly-Asp; Glu: glutamic acid; 6-Ahx: 6-amino hexanoic acid; RM2: (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2)) was conjugated to a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) bifunctional chelator (BFCA) purified via reversed-phase high-performance liquid chromatography (RP-HPLC), characterized by electrospray ionization-mass spectrometry (ESI-MS), and radiolabeled with111 In or177 Lu. Natural-metallated compounds were assessed for binding affinity for the αV β3 integrin or GRPr in human glioblastoma U87-MG and prostate PC-3 cell lines and stability prior to in vivo evaluation in normal CF-1 mice and SCID mice xenografted with PC-3 cells. Results Competitive displacement binding assays with PC-3 and U87-MG cells revealed high to moderate binding affinity for the GRPr or the αV β3 integrin (IC50 range of 5.39 ± 1.37 nM to 9.26 ± 0.00 nM in PC-3 cells, and a range of 255 ± 47 nM to 321 ± 85 nM in U87-MG cells). Biodistribution studies indicated high tumor uptake in PC-3 tumor-bearing mice (average of 7.40 ± 0.53% ID/g at 1 h post-intravenous injection) and prolonged retention of tracer (mean of 4.41 ± 0.91% ID/g at 24 h post-intravenous injection). Blocking assays corroborated the specificity of radioconjugates for each target. Micro-single photon emission computed tomography (microSPECT) confirmed favorable radiouptake profiles in xenografted mice at 20 h post-injection. Conclusions RGD-Glu-111 In-DO3A-6-Ahx-RM2 and RGD-Glu-177 Lu- DO3A-6-Ahx-RM2 show favorable pharmacokinetic and radiouptake profiles, meriting continued evaluation for molecular imaging in murine U87-MG/PC-3 xenograft models and radiotherapy studies with177 Lu and90 Y conjugates. Advances in Knowledge and Implications for Patient Care These heterovalent, peptide-targeting ligands perform comparably with many mono- and multivalent conjugates with the potential benefit of increased sensitivity for detecting cancer cells exhibiting differential expression of target receptors.
We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the ...fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2.
STK15 (Aurora-A) is a serine/threonine kinase involved in mitotic chromosomal segregation. A genetic variant in STK15 T+91A (resulting in the amino acid substitution F31I) is associated with ...increased aneuploidy in colon tumors and cell transformation in vitro. Since this polymorphism plays a role in mitotic control—a process critical for all cancer types—we conducted association analyses for risk of cancer development of the colon, breast, prostate, skin, lung and esophagus in 10 independent case–control populations. We carried out a meta-analysis of these 10 case–control studies together with 5 additional published studies for a total of 9549 cases of breast, colon, ovarian, prostate, lung, esophageal and non-melanoma skin cancer and 8326 population or hospital-based controls. Meta-analysis of three colorectal cancer studies showed an increased risk in T+91A homozygotes (OR = 1.50; 95% CI of 1.14–1.99). Meta-analysis of four breast cancer studies showed increased risk for T+91A homozygotes (OR = 1.35, 95% CI of 1.12–1.64). The results of the multiple cancer type meta-analysis for all 15 studies combined were significant for cancer risk in both homozygotes and heterozygotes. The T+91A heterozygotes show an OR of 1.10 (95% CI of 1.03–1.18, P-value = 0.006) and the T+91A homozygotes show an OR of 1.40 (95% CI of 1.22–1.59, P-value <0.001) for cancer risk. These results confirm that the STK15 T+91A variant is a low penetrance cancer susceptibility allele affecting multiple cancer types, and provide genetic evidence from large-scale human population studies that genetic stability at the chromosome level is an important determinant of cancer susceptibility. The data also underline the advantages of comparative association studies involving study populations from different ethnic groups for determination of disease risk.
A three-dimensional smoothed particle hydrodynamics model has been extended to study the radiation-driven implosion effect of massive stars on the dynamical evolution of surrounding molecular clouds. ...The new elements in the upgraded code are the inclusion of Lyman continuum in the incident radiation flux and the treatment of hydrogen ionization process; the introduction of ionization heating and recombination cooling effects; and the addition of a proper description of the magnetic and turbulent pressures to the internal pressure of the molecular cloud. This extended code not only provides a realistic model to trace the dynamical evolution of a molecular cloud, but also can be used to model the kinematics of the ionization and shock fronts and the photoevaporating gas surrounding the molecular cloud, which the previous code is unable to handle. The application of this newly developed model to the structure of the middle Eagle nebula finger suggests that the shock induced by the ionizing radiation at the front side of the head precedes an ionization front moving towards the centre of the core, and that the core at the fingertip is at a transition stage evolving toward a state of induced star formation. The dynamical evolution of the velocity field of the simulated cloud structure is discussed to illustrate the role of the self-gravity and the different cloud morphologies which appear at different stages in the evolutionary process of the cloud. The motion of the ionization front and the evaporating gas are also investigated. The modelled gas evaporation rate is consistent with that of other current models and the density, temperature and chemical profiles are in agreement with the observed values. The relative lifetimes of different simulated cloud morphologies suggest a possible answer to the question of why more bright-rimmed clouds are observed to possess a flat-core than an elongated-core morphology.
Elderly people represent a growing stroke population with different pathophysiological states than younger. Whether intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) is beneficial ...for elderly patients remains unclear. This study compared the efficacy and safety between elderly patients treated with MT alone and those treated with both IVT and MT.
Patients aged ≥65 years who were eligible for IVT within 4.5 h from symptom onset were selected from the ANGEL-ACT (Endovascular Treatment Key Technique and Emergency Work Flow Improvement of Acute Ischemic Stroke) registry, a prospective registry program for patients with endovascular treatment from 111 Chinese stroke centers. The primary efficacy outcome was the 90-day modified Rankin Scale score. We compared efficacy and safety outcomes using ordinal or binary logistic regression or a generalized linear model.
In total, 482 elderly patients were included: 187 (38.8%) received IVT and MT (bridging MT) and 295 (61.2%) received MT alone (direct MT). There was no significant difference in the 90-day modified Rankin Scale score between the two groups (median: 4 vs 4 points, respectively; adjusted β=-0.048,
=0.822). The direct MT group had a shorter onset-to-puncture time (225 vs 255 min, respectively; adjusted β=-55.074,
=0.002) and a lower rate of parenchymal hemorrhage type 2 within 24 h (2.80% vs 6.63%, respectively; adjusted odds ratio OR=0.287, 95% confidence interval CI=0.096-0.856,
=0.025). In addition, the direct MT group showed a trend toward a lower incidence of sICH (5.67% vs 10.06%, adjusted OR=0.453,
=0.061), procedure-related complications (7.12% vs 12.30%, adjusted OR=0.499,
=0.052) and distal or new territorial embolization (4.07% vs 6.95%, adjusted OR=0.450,
=0.093).
Direct MT had similar efficacy to bridging MT in terms of the 90-day functional outcome in elderly patients, whereas bridging MT had a longer onset-to-puncture time and increased risk of hemorrhagic transformation and procedure-related complications.
Abstract We present high-cadence ultraviolet through near-infrared observations of the Type Ia supernova (SN Ia) 2023bee at D = 32 ± 3 Mpc, finding excess flux in the first days after explosion, ...particularly in our 10 minutes cadence TESS light curve and Swift UV data. Compared to a few other normal SNe Ia with early excess flux, the excess flux in SN 2023bee is redder in the UV and less luminous. We present optical spectra of SN 2023bee, including two spectra during the period where the flux excess is dominant. At this time, the spectra are similar to those of other SNe Ia but with weaker Si ii , C ii, and Ca ii absorption lines, perhaps because the excess flux creates a stronger continuum. We compare the data to several theoretical models on the origin of early excess flux in SNe Ia. Interaction with either the companion star or close-in circumstellar material is expected to produce a faster evolution than observed. Radioactive material in the outer layers of the ejecta, either from double detonation explosion or from a 56 Ni clump near the surface, cannot fully reproduce the evolution either, likely due to the sensitivity of early UV observable to the treatment of the outer part of ejecta in simulation. We conclude that no current model can adequately explain the full set of observations. We find that a relatively large fraction of nearby, bright SNe Ia with high-cadence observations have some amount of excess flux within a few days of explosion. Considering potential asymmetric emission, the physical cause of this excess flux may be ubiquitous in normal SNe Ia.
Dispersal can limit local plant distribution Primack, R.B. (Boston University, Boston, MA); Miao, S.L
Conservation biology,
December 1992, Letnik:
6, Številka:
4
Journal Article
Recenzirano
The ability of species to establish new populations at unoccupied sites is a critical feature in the maintenance of biological diversity, and it has taken on new importance as a result of global ...climate change and expected changes in species distribution. To examine the dispersal potential of plant species, seeds of four annual plant species were experimentally dispersed 40 to 600 m from existing populations in Massachusetts (U.S.A.) to 34 nearby unoccupied but apparently suitable sites. At three of these sites, new populations were established that persisted for four generations and expanded slowly in area. At seven sites, a small initial population eventually died out. At the 24 other sites, new populations did not become established, indicating that the sites were in some way unsuitable, that not enough seeds arrived, or that conditions suitable for seed germination do not occur every year. These results suggest that some species may be unable to disperse naturally out of their existing ranges in response to global climate change, particularly if habitat fragmentation creates barriers to dispersal. These species may have to be assisted to reach suitable sites nearby to prevent their extinction in the wild.
ADP-ribosylation-like factor 6 interacting protein 5 (Arl6ip5), which belongs to the prenylated rab-acceptor-family, has an important role in exocytic protein trafficking, glutathione metabolism and ...involves in cancer progression. However, its expression pattern and functional role in bone are unknown. Here we demonstrate that Arl6ip5 knock-out mice (Arl6ip5 (Δ2/Δ2)) show marked decrease of bone mineral density, trabecular bone volume and trabecular thickness. Histomorphometric studies reveal that bone formation parameters are decreased but bone resorption parameters and mRNA level of osteoclast-specific markers are increased in Arl6ip5(Δ2/Δ2) mice. In osteoblast, we demonstrate that Arl6ip5 abundantly expresses in osteoblastic cells and is regulated by bone metabolism-related hormones and growth factors. In vitro analysis reveals that osteoblast proliferation and differentiation are impaired in Arl6ip5 knocked-down and deficient primary osteoblast. Arl6ip5 is also found to function as an ER calcium regulator and control calmodulin signaling for osteoblast proliferation. Moreover, Arl6ip5 insufficiency in osteoblast induces ER stress and enhances ER stress-mediated apoptosis. CCAAT/enhancer-binding protein homologous protein (Chop) is involved in the regulation of apoptosis and differentiation in Arl6ip5 knocked-down osteoblasts. For osteoclastogenesis, Arl6ip5 insufficiency in osteoclast precursors has no effect on osteoclast formation. However, knocked-down osteoblastic Arl6ip5 induces receptor activator of nuclear factor-κB ligand (RANKL) expression and enhances osteoclastogenesis. In addition, ER stress and Chop are involved in the RANKL expression in Arl6ip5 knocked-down osteoblasts. In conclusion, we demonstrate that Arl6ip5 is a novel regulator of bone formation in osteoblasts.
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