The as-extruded AZ91D magnesium alloy processed by conventional extrusion exhibits a yield strength of 320 MPa, an ultimate tensile strength of 382 MPa and a fracture elongation of 13.8%, superior ...than most AZ91D alloys reported so far, which is mainly attributed to ultra-fine grains, sub-micron precipitates, and strong texture.
An extruded Mg-5Zn-2.5Y-1Ce-0.5Mn alloy with uniform fine α-Mg grains, dispersed W-phase and T-phase and weak basal texture was prepared by the semi-continuous casting and one-pass extrusion methods. ...The deformation behaviors of the extruded alloy were tested at a temperature range from room temperature (RT) to 350 °C and a strain rate range from 1×10−2s−1 to 4×10−4s−1. The results and relevant mechanisms were analyzed by using the measured data of the strain rate sensitivity (m) and the activation energy (Q) and the observations of the morphologies of deformation and fracture surfaces. It was demonstrated that the tensile strengths decrease, while the elongation to failure tends to increase with increasing temperature or decreasing strain rate. The variation in mechanical properties with increasing temperature mainly arises from a change in opening deformation mechanisms from the dislocation slip at RT to the dislocation climb at 250 °C to the grain boundary (GB) sliding at 350 °C. At RT, the slightly decreased tensile strengths and slightly increased elongation to failure with decreasing strain rate are mainly attributed to the weak sensitivity of the dislocation slip to strain rate. At 250 °C, the lower tensile strengths and the larger elongation to failure at 4×10−4s−1 than that at 1×10−2s−1 are mainly attributed to the occurrence of the dynamic recrystallization (DRX) at lower strain rate, while such DRX does not occur at higher strain rate. At 350 °C, the lower tensile strengths and the much larger elongation to failure at 4×10−4s−1 than that at 1×10−2s−1 are attributed to the GB sliding accommodated by the lattice diffusion at lower strain rate, while the GB sliding at higher strain rate is accommodated by the GB diffusion.
Inter-simple sequence repeat (ISSR) markers generated by 22 primers were tested for their ability to distinguish among samples from 94 trees of 68 citrus cultivars. Within each of the six cultivar ...groups studied most of these cultivars are so closely related that they are difficult to distinguish by other molecular-marker techniques. ISSR markers involve PCR amplification of DNA using a single primer composed of a microsatellite sequence anchored at the 3' or 5' end by 2-4 arbitrary, often degenerate, nucleotides. The amplification products were separated on non-denaturing polyacrylamide gels and detected by silver staining. ISSR banding profiles were very repeatable on duplicate samples. Different citrus species had very different fingerprint patterns. Within Citrus sinensis (L.) Osbeck and C. paradisi Macf., in which all cultivars have originated by the selection of mutants, ISSR markers distinguished 14 of 33 sweet orange and 1 of 7 grapefruit cultivars. Five of six lemon cultivars were discriminated by ISSR markers. Many differences were found among mandarin cultivars; however, all five satsuma cultivars analyzed had identical ISSR fingerprints. Four of five citrange cultivars were distinguishable, but 'Troyer' and 'Carrizo' had identical ISSR fingerprints. 'Kuharske Carrizo' citrange, which has better citrus nematode resistance than other 'Carrizo' citrange accessions, had unique ISSR fingerprints. Three ISSR markers that differentiated certain sweet orange cultivars were hybridized to Southern blots of sweet orange DNA digested with different restriction endonucleases. The sweet orange cultivars tested could be distinguished by these ISSR-derived RFLP markers. Moreover, one ISSR marker unique to 'Ruby' blood orange was observed in its progeny trees.
The CUORE experiment is a ton-scale array of
TeO
2
cryogenic bolometers located at the underground Laboratori Nazionali del Gran Sasso of Istituto Nazionale di Fisica Nucleare (INFN), in Italy. The ...CUORE detector consists of 988 crystals operated as source and detector at a base temperature of
∼
10
mK. Such cryogenic temperature is reached and maintained by means of a custom built cryogen-free dilution cryostat, designed with the aim of minimizing the vibrational noise and the environmental radioactivity. The primary goal of CUORE is the search for neutrinoless double beta decay of
130
Te
, but thanks to its large target mass and ultra-low background it is suitable for the study of other rare processes as well, such as the neutrinoless double beta decay of
128
Te
. This tellurium isotope is an attractive candidate for the search of this process, due to its high natural isotopic abundance of 31.75%. The transition energy at (866.7 ± 0.7) keV lies in a highly populated region of the energy spectrum, dominated by the contribution of the two-neutrino double beta decay of
130
Te
. As the first ton-scale infrastructure operating cryogenic
TeO
2
bolometers in stable conditions, CUORE is able to achieve a factor
>
10
higher sensitivity to the neutrinoless double beta decay of this isotope with respect to past direct experiments.
In this contribution we present the achievements of the CUORE experiment so far. It is the first tonne-scale bolometric detector and it is in stable data taking since 2018. We reached to collect ...about 1800 kg×yr of exposure of which more than 1 ton×year have been analysed. The CUORE detector is meant to search for the neutrinoless double β decay (0νββ) of the 130Te isotope. This is a beyond Standard Model process which could establish the nature of the neutrino to be Dirac or a Majorana particle. It is an alternative mode of the two-neutrinos double β decay, a rare decay which have been precisely measured by CUORE in the 130Te. We found no evidence of the 0νββ and we set a Bayesian lower limit of 2.2 ×1025yr on its half-life. The expertise achieved by CUORE set a milestone for any future bolometric detector, including CUPID, which is the planned next generation experiment searching for 0νββ with scintillating bolometers.
Relationships among 88 accessions representing 45 Citrus species, three man-made hybrids, and six related genera were examined for restriction fragment length polymorphisms (RFLP). Thirty-two Citrus ...and three Microcitrus accessions were also examined by random amplified polymorphic DNA (RAPD) analysis. A measure of relative heterozygosity was estimated based on the mean of the number of fragments per individual per probe-enzyme combination (PEC) divided by total number of fragments per PEC for all non-hybrid Citrus individuals. The presence in a Citrus species of a rare band found also in a related genus was taken as an indication of possible introgression, while the presence of several fragments unique to 1 species was used to indicate non-involvement of that species in hybridization events. Most species that have been described in the literature as hybrids had high heterozygosity indices and no unique fragments. Distance matrices and dendrograms were generated using simple matching coefficient and neighbor-joining cluster analysis. RFLP and RAPD data gave approximately the same results. These data showed C. maxima was affiliated with the papedas C. hongheensis and C. latipes. C. medica clustered with C. indica when only nonhybrid taxa were examined, or among limes, lemons, and relatives when all species were considered. Mandarins did not show strongly supported groupings among themselves, nor with other species. These data showed that several accessions were probably assigned to the wrong species.
Trifoliate orange Poncirus trifoliata (L.) Raf. is frequently used as a parent in citrus rootstock breeding, but the origin and amount of genetic diversity in germ plasm collections are poorly ...understood. Most accessions are self-compatible, but produce a mixture of sexual and apomictic seedlings. Variation among 48 vegetatively propagated trifoliate orange accessions was assessed at seven isozyme loci, together with the restriction fragment length polymorphisms (RFLPs) detected by 38 probe-enzyme combinations and the inter-simple sequence repeat (ISSR) markers generated by 11 primers. Isozymes and RFLPs detected few polymorphisms among accessions, although genetic analysis has shown that the common phenotype is heterozygous for four isozyme and at least four RFLP loci. ISSR amplification generated multiple banding profiles with an average of 58 fragments/primer/accession. These fragments were repeatable across DNA samples extracted from different trees of the same accession or extracted at different times, and across separate PCR runs. Seventeen unique marker phenotypes were identified. The 48 trifoliate orange accessions were classified into four major groups based on polymorphic ISSR markers. All large-flowered accessions are in group 4, while small-flowered accessions are in group 3. Many ISSR markers segregated in progeny derived by open-pollination (probably mostly selfing) of a common accession, indicating that these ISSR markers are also heterozygous. Accessions having identical genotypes for a large number of heterozygous markers are unlikely to have diverged by recombination. Thus the limited divergence we detected among most accessions most likely originated by mutation. 'Monoembryonic' and 'Simmons' differed from other accessions only in the loss of specific markers, indicating that they originated as zygotic seedlings of individuals similar to the common genotype. Three accessions recently introduced from China have relatively different fingerprints with 3-14 unique ISSR markers, and probably represent a much more divergent germ plasm that may be a valuable breeding resource.
1 Cardiology and the Key Lab on Assisted Circulation of the Health Ministry of China, The First Affiliated Hospital/Sun Yat-sen University, Guangzhou, Peoples Republic of China; 2 Cardiology and 3 ...Cardiac Surgery, Harvard Medical School/Beth Israel Deaconess Medical Center, Boston, Massachusetts; and 4 Cardiology, State University of New York at Stony Brook, Stony Brook, New York
Submitted 6 December 2004
; accepted in final form 17 August 2005
Enhanced external counterpulsation (EECP) is an effective noninvasive treatment of coronary artery disease. Its mechanism of action remains unknown. An acute coronary occlusion dog model was created to explore the angiogenic effect of EECP. After coronary occlusion, 12 dogs were randomly assigned to either EECP ( n = 6) or control ( n = 6). Immunohistochemical studies of -actin and von Willebrand factor (vWF) were used to detect newly developed microvessels. Systemic and local vascular endothelial growth factor (VEGF) were identified by ELISA and reverse transcriptase PCR analysis. There was a significant increase in the density of microvessels per squared millimeter in the infarcted regions of the EECP group compared with the control group (vWF, 15.2 ± 6.3 vs. 4.9 ± 2.1, P < 0.05; -actin, 11.8 ± 5.3 vs. 3.4 ± 1.2, P < 0.05). The positive-stained area per squared micrometer also increased significantly ( -actin, 6.6 x 10 3 ± 2.9 x 10 3 µm 2 vs. 0.6 x 10 3 ± 0.5 x 10 3 µm 2 , P < 0.05; vWF, 5.7 x 10 3 ± 1.9 x 10 3 µm 2 vs. 1.7 x 10 3 ± 1.4 x 10 3 µm 2 , P < 0.05). Immunohistochemical staining and reverse transcriptase PCR analysis documented a significant increase in VEGF expression. These factors associated with angiogenesis corresponded to improved myocardial perfusion by 99m Tc-sestamibi single-photon emission computed tomography. Angiogenesis may be a mechanism of action for the improved myocardial perfusion demonstrated after EECP therapy.
angiogenesis; collateral circulation; growth factors; infarction; ventricular function
Address for reprint requests and other correspondence: W. E. Lawson, State Univ. of New York at Stony Brook, HSC, Level 16, Rm. 080, Stony Brook, NY 11794 (email: wlawson{at}ts.uh.sunysb.edu )
Radioactive ion beams were produced through the projectile fragmentation induced by 69 MeV/ nucleon
36Ar primary beam on a
9Be target. Measurements of reaction cross sections (
σ
R
's) for 44 nuclei ...with
A<30 (mostly proton-rich), on carbon were performed on RIBLL (Radioactive Ion Beam Line in Lanzhou) of HIRFL (Heavy Ion Research Facility in Lanzhou) at intermediate energies around 30 MeV/nucleon by a transmission method. The experimental
σ
R
values for
23Al and
27P are abnormally large compared with their neighboring nuclei. Together with the previous experimental facts such as the binding energy and ground state data, it suggests anomalously large matter root-mean-square radii and proton halo structure in
23Al and in
27P. There is an enhancement for the
σ
R
of
17F
+
12C compared with the neighboring isotopes. Considering that the ground state of
17F is 1
d
5/2, this can indicate that there is a proton skin in
17F. The calculation of relativistic density-dependent Hartree model (RDDH) shows that the nuclei
23Al and
27P may have proton-halo structure and
17F may have proton-skin structure. The significance of these measurements is discussed.
Results from the CUORE experiment Campani, A; Adams, DQ; Alduino, C ...
Il Nuovo Cimento C,
2019, Letnik:
42, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Neutrinoless double beta decay (0νββ) is a rare, second-order nuclear transition that occurs only if neutrinos are massive Majorana particles or through new physics beyond Standard Model. This ...process explicitly violates the lepton number (L) by two units and, therefore, the observation of 0νββ would demonstrate that L is not a symmetry of nature. Combined with flavour mixing and cosmological measurements, it can provide unique contraints on neutrino mass scale and establish whether neutrinos are Dirac or Majorana particles. The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment located at the LNGS searching for 0νββ decay of 130Te. CUORE exploits the bolometric technique to reach high resolution around the Q-value (2527.5 keV). It consists of an array of 988 natural TeO2 cubic crystals grouped into 19 towers. With a total active mass of 742 kg (~206 kg of 130Te), CUORE is operated at very low temperature with a new 3He/4He refrigerator. Data taking started at the beginning of 2017. After a brief introduction on the detector and the way data analysis is performed, I describe CUORE first results for the search of the 0νββ decay that were published in March 2018.
