516 research outputs found
A Patterned Single Layer Graphene Resistance Temperature Sensor
Micro-fabricated single-layer graphenes (SLGs) on a silicon dioxide (SiO2)/Si substrate, a silicon nitride (SiN) membrane, and a suspended architecture are presented for their use as temperature sensors. These graphene temperature sensors act as resistance temperature detectors, showing a quadratic dependence of resistance on the temperature in a range between 283 K and 303 K. The observed resistance change of the graphene temperature sensors are explained by the temperature dependent electron mobility relationship (~T−4) and electron-phonon scattering. By analyzing the transient response of the SLG temperature sensors on different substrates, it is found that the graphene sensor on the SiN membrane shows the highest sensitivity due to low thermal mass, while the sensor on SiO2/Si reveals the lowest one. Also, the graphene on the SiN membrane reveals not only the fastest response, but also better mechanical stability compared to the suspended graphene sensor. Therefore, the presented results show that the temperature sensors based on SLG with an extremely low thermal mass can be used in various applications requiring high sensitivity and fast operation
Mutant pattern of p53 predicts local recurrence and poor survival rate in gastric cancer
Background. TP53 mutation is a poor
prognostic factor for various organ malignancies such as
colorectal cancer, breast cancer, ovarian cancer,
hepatocellular carcinoma, lung adenocarcinoma and
clinical pathologists previously evaluated it using
immunohistochemistry for p53. The clinicopathologic
significance of p53 expression in gastric cancer remains
unclear due to inconsistent classification methods.
Methods. Immunohistochemistry for p53 protein
was performed using tissue microarray blocks generated
from 725 cases of gastric cancer, and p53 expression
was divided into three staining patterns using a semiquantitative ternary classifier: heterogeneous (wild type),
overexpression, and absence (mutant pattern).
Results. Mutant pattern of p53 expression had a
male predominance, greater frequency in cardia/fundus,
higher pT stage, frequent lymph node metastasis, local
recurrence clinically, and more differentiated histology
microscopically compared with wild type. In survival
analysis, p53 mutant pattern was associated with worse
recurrent-free survival and overall survival rates, and
significance was maintained in subgroup analysis of
early versus advanced gastric cancers. In Cox regression
analysis, p53 mutant pattern was a significant predicting
factor for local recurrence (relative risk (RR=4.882,
p<0.001)) and overall survival (RR=2.040, p=0.007).
The p53 mutant pattern remained significant for local
recurrence (RR=2.934, p=0.018) in multivariate
analyses.
Conclusions. Mutant p53 pattern on immunohistochemistry was a significant prognostic factor for
local recurrence and poor overall survival in gastric
cancer
Whole Genome Analysis of the Red-Crowned Crane Provides Insight into Avian Longevity
The red-crowned crane (Grus japonensis) is an endangered, large-bodied crane native to East Asia. It is a traditional symbol of longevity and its long lifespan has been confirmed both in captivity and in the wild. Lifespan in birds is known to be positively correlated with body size and negatively correlated with metabolic rate, though the genetic mechanisms for the red-crowned crane's long lifespan have not previously been investigated. Using whole genome sequencing and comparative evolutionary analyses against the grey-crowned crane and other avian genomes, including the long-lived common ostrich, we identified red-crowned crane candidate genes with known associations with longevity. Among these are positively selected genes in metabolism and immunity pathways (NDUFA5, NDUFA8, NUDT12, SOD3, CTH, RPA1, PHAX, HNMT, HS2ST1, PPCDC, PSTK CD8B, GP9, IL-9R, and PTPRC). Our analyses provide genetic evidence for low metabolic rate and longevity, accompanied by possible convergent adaptation signatures among distantly related large and long-lived birds. Finally, we identified low genetic diversity in the red-crowned crane, consistent with its listing as an endangered species, and this genome should provide a useful genetic resource for future conservation studies of this rare and iconic species
Realization of giant magnetoelectricity in helimagnets
We show that low field magnetoelectric (ME) properties of helimagnets
Ba0.5Sr1.5Zn2(Fe1-xAlx)12O22 can be efficiently tailored by Al-substitution
level. As x increases, the critical magnetic field for switching electric
polarization is systematically reduced from ~1 T down to ~1 mT, and the ME
susceptibility is greatly enhanced to reach a giant value of 2.0 x 10^4 ps/m at
an optimum x = 0.08. We find that control of nontrivial orbital moment in the
octahedral Fe sites through the Al-substitution is crucial for fine tuning of
magnetic anisotropy and obtaining the conspicuously improved ME
characteristics
Nonlinear Color-Metallicity Relations of Globular Clusters. III. On the Discrepancy in Metallicity between Globular Cluster Systems and their Parent Elliptical Galaxies
One of the conundrums in extragalactic astronomy is the discrepancy in
observed metallicity distribution functions (MDFs) between the two prime
stellar components of early-type galaxies-globular clusters (GCs) and halo
field stars. This is generally taken as evidence of highly decoupled
evolutionary histories between GC systems and their parent galaxies. Here we
show, however, that new developments in linking the observed GC colors to their
intrinsic metallicities suggest nonlinear color-to-metallicity conversions,
which translate observed color distributions into strongly-peaked, unimodal
MDFs with broad metal-poor tails. Remarkably, the inferred GC MDFs are similar
to the MDFs of resolved field stars in nearby elliptical galaxies and those
produced by chemical evolution models of galaxies. The GC MDF shape,
characterized by a sharp peak with a metal-poor tail, indicates a virtually
continuous chemical enrichment with a relatively short timescale. The
characteristic shape emerges across three orders of magnitude in the host
galaxy mass, suggesting a universal process of chemical enrichment among
various GC systems. Given that GCs are bluer than field stars within the same
galaxy, it is plausible that the chemical enrichment processes of GCs ceased
somewhat earlier than that of field stellar population, and if so, GCs
preferentially trace the major, vigorous mode of star formation events in
galactic formation. We further suggest a possible systematic age difference
among GC systems, in that the GC systems in more luminous galaxies are older.
This is consistent with the downsizing paradigm of galaxies and supports
additionally the similar nature shared by GCs and field stars. Our findings
suggest that GC systems and their parent galaxies have shared a more common
origin than previously thought, and hence greatly simplify theories of galaxy
formation.Comment: 55 pages, 7 figures, 5 tables; Accepted for publication in Ap
Oldenlandia diffusa Promotes Antiproliferative and Apoptotic Effects in a Rat Hepatocellular Carcinoma with Liver Cirrhosis
Oldenlandia diffusa (OD) is commonly used with various diseases such as cancer, arthritis, and autoimmune disease. Liver cirrhosis is a predominant risk factor for hepatocellular carcinoma (HCC). Here, we show that the therapeutic effect of OD, which was investigated both in vitro and chemically, induced HCC model. OD significantly enhanced apoptosis and antiproliferative activity and reduced migration ability of HCC cells. In vivo, OD was treated twice a day for 28 days after confirmed HCC model through 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) imaging. The survival in OD treated groups was shown to have a greater therapeutic effect than the control group. 28 days after OD treatment, OD treated groups resulted in a significant reduction in tumor number, size, (18)F-FDG uptake, and serum levels such as alanine transaminase, aspartate transaminase, and alkaline phosphate compared to the control group. Also, proliferated cells in tumor sites by OD were reduced compared to the control group. Furthermore, several rats in OD treated group survived over 60 days and liver morphology of these rats showed the difference between tumor mass and normal tissue. These results suggest that OD may have antiproliferative activity, inhibition of metastasis, and apoptotic effects in chemically induced HCC model and can have the potential use for clinical application as anticancer drug of the herbal extract
Pseudotumor of the Omentum Associated with Migration of the Ingested Crab-Leg
Foreign body ingestion is not uncommon in clinical practice, and it may occasionally lead to penetration injuries. Emergency physicians and radiologists sometimes fail to obtain complete histories including ingestion and may overlook the possibility of foreign body-induced complications. Herein, we report a case of stomach antrum perforation due to foreign body migration. We were unaware of the patient's history of eating the Korean delicacy "Kanjang-gaejang," which is raw crab seasoned with soy sauce. Several imaging diagnostic modalities had suggested the possibility of a malignant mass in the gastrocolic ligament area. During the operation, a crab leg was discovered as the cause of an intra-abdominal abscess. The patient underwent an antrectomy, a vagotomay, and a transverse colon wedge resection. We present this unusual case of a pseudotumorous lesion caused by ingestion of Kanjang-gaejang
Prognostic Significance of Human Papillomavirus Type 16 and 18 in Cervical Cancer
To assess the prognostic significance of Human papillomavirus
(HPV) type 16 and 18 which have been supposed as high risk oncogenic viruses
in cervical cancer, polymerase chain reaction (PCR) was used to determine HPV
type in formalin fixed paraffin embedded tissue blocks. Samples were obtained
from patients with stage I and II cervical cancer who underwent surgery from
1985 to 1986 at Seoul National University Hospital. In total 65 patients were enlisted,
but 9 patients were excluded in data analysis because of poor amplification of
,a-globin during the PCR procedure. Cilnicopathologic factors (age, stage, histologic
type, tumor size, lymph node metastasis) and 5 year survival rate were compared
between HPV positive and HPV negative groups. The survival difference between
HPV 16 positive and HPV 18 positive cases was also analyzed. HPV 16 /18 positive
rate in cervical cancer is 80.4%(45 /56), and there is no significant difference
in age, stage, histologic type, tumor size, nodal metastasis by HPV infection status.
No difference was found in 5 year survival rate between HPV positive and negative
groups. When compared with the HPV 16 positive group, the HPV 18 positive
group did not show any difference in prognosis. These data suggested that the
presence of HPV 16 or HPV 18 in cervical cancer had no relation with known
prognostic factors. Either HPV positivity or HPV type (HPV 16 \IS. HPV 18) did not
have any prognostic significance in cervical cancer
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