Superconductivity in the PbO-type structure α-FeSe Hsu, Fong-Chi; Luo, Jiu-Yong; Yeh, Kuo-Wei ...
Proceedings of the National Academy of Sciences - PNAS,
09/2008, Letnik:
105, Številka:
38
Journal Article
Recenzirano
Odprti dostop
The recent discovery of superconductivity with relatively high transition temperature (Tc) in the layered iron-based quaternary oxypnictides LaO₁₋xFx FeAs by Kamihara et al. Kamihara Y, Watanabe T, ...Hirano M, Hosono H (2008) Iron-based layered superconductor LaO1-xFx FeAs (x = 0.05-0.12) with Tc = 26 K. J Am Chem Soc 130:3296-3297. was a real surprise and has generated tremendous interest. Although superconductivity exists in alloy that contains the element Fe, LaOMPn (with M = Fe, Ni; and Pn = P and As) is the first system where Fe plays the key role to the occurrence of superconductivity. LaOMPn has a layered crystal structure with an Fe-based plane. It is quite natural to search whether there exists other Fe based planar compounds that exhibit superconductivity. Here, we report the observation of superconductivity with zero-resistance transition temperature at 8 K in the PbO-type α-FeSe compound. A key observation is that the clean superconducting phase exists only in those samples prepared with intentional Se deficiency. FeSe, compared with LaOFeAs, is less toxic and much easier to handle. What is truly striking is that this compound has the same, perhaps simpler, planar crystal sublattice as the layered oxypnictides. Therefore, this result provides an opportunity to better understand the underlying mechanism of superconductivity in this class of unconventional superconductors.
Pancreatic adenocarcinoma (PDAC) is a leading cause of cancer-related death. Altered glycosylation contributes to tumor progression and chemoresistance in many cancers. C1GALT1 is the key enzyme ...controlling the elongation of GalNAc-type O-glycosylation. Here we showed that C1GALT1 was overexpressed in 85% (107/126) of PDAC tumors compared with adjacent non-tumor tissues. High expression of C1GALT1 was associated with poor disease-free and overall survival (n = 99). C1GALT1 knockdown using siRNA suppressed cell viability, migration, and invasion as well as increased gemcitabine sensitivity in PDAC cells. In contrast, C1GALT1 overexpression enhanced cell migration and invasion. In subcutaneous and pancreatic orthotopic injection models, C1GALT1 knockdown decreased tumor growth and metastasis of PDAC cells in NOD/SCID mice. Mechanistically, C1GALT1 knockdown dramatically suppressed cell-extracellular matrix (ECM) adhesion, which was associated with decreased phosphorylation of FAK at Y397/Y925 and changes in O-glycans on integrins including the β
, α
, and α
subunits. Using functional blocking antibodies, we identified integrin α
as a critical factor in C1GALT1-mediated invasiveness of PDAC cells. In conclusion, this study not only reveals that C1GALT1 could be a potential therapeutic target for PDAC but also provides novel insights into the role of O-glycosylation in the α subunits of integrins.
The content of several phenolic acids and flavonoids in aqueous extract (AE) and ethanol extract (EE) of daylily flower (Hemerocallis fulva L.) was analyzed. The effects of AE or EE at 0.5%, 1%, or ...2% in HUVE cells against high glucose‐induced cell death, oxidative, and inflammatory damage were examined. Results showed that seven phenolic acids and seven flavonoids could be detected in AE or EE, in the range of 29 to 205 and 41 to 273 mg/100 g, respectively. Compared with the control groups, high glucose raised the activity of caspase‐3 and caspase‐8; suppressed Bcl‐2 mRNA expression and increased Bax mRNA expression; and induced HUVE cells apoptosis. The pretreatments from AE or EE at 1% or 2% reduced caspase‐3 activity and Bax mRNA expression, and enhanced cell viability. High glucose decreased glutathione content; stimulated the production of reactive oxygen species, interleukin‐6, tumor necrosis factor‐alpha, and prostaglandin E2; raised the activity of cyclooxygenase‐2 and nuclear factor kappa B p50/65 binding; and reduced the activity of glutathione peroxidase, glutathione reductase, and catalase in HUVE cells. AE pretreatments at 1% and 2% reversed these changes. These novel findings suggested that daylily flower was rich in phytochemicals, and could be viewed as a potent functional food against diabetes.
A flow-injection analytical (FIA) system was developed for the determination of cholesterol concentrations based on enzymatic reactions that occurred in a cholesterol oxidase (CHOx)-immobilized, ...fused-silica capillary followed by electrochemical detection. The production of hydrogen peroxide from cholesterol in an enzymatic reaction catalyzed by CHOx was subsequently oxidized electrochemically at an electrode. Our FlA system demonstrated its cost-effectiveness and utility at an applied potential of 0.6 V (vs. Ag/AgCl), a flow rate of 100 μL/min and, under optimal conditions, the resulting signal demonstrated a linear dynamic range from 50 μM to 1.0 mM with a limit of detection (LOD) of 12.4 μM, limit of quantification (LOQ) of 44.9 μM, and the coefficient of variation of 5.17%. In addition, validation of our proposed system using a reference HDL-cholesterol kit used for clinical diagnosis suggested our FIA system was comparable to commercial kits for the determination of the cholesterol incorporation amount in various aqueous liposomal suspensions. These good analytical features achieved by FIA could make the implementation of this methodology possible for on-line monitoring of cholesterol in various types of samples.
Purpose
The agricultural lands in most Asian countries have been contaminated by pesticides for decades, especially γ-hexachlorocyclohexane (lindane) and dichlorodiphenyltrichloroethane (DDT). For ...most sites, the concentrations are in the parts per million level favoring bioremediation. However, due to high hydrophobicity, they are hard to be biodegraded in soils. In situ phase inversion emulsification and biological reductive dechlorination (ISPIE/BiRD) is proposed as an effective approach for the removal of lindane and DDT in soil.
Materials and methods
Three tests were conducted, i.e., a batch test, a column test, and a sandbox test. In the batch test, the Taguchi method was applied to define optimum environmental parameters, such as pH, water content, emulsion concentration, and soil organic matter level. A column test was performed using a real agricultural soil to define the removal efficiency of a single operation of ISPIE on lindane and DDT. A sandbox was employed to test if the remaining emulsion can assist in the biodegradation of lindane and DDT in a real agricultural soil. Next-generation sequencing (NGS) was performed to profile the microbial community for the best groups in the batch test and the sandbox test.
Results and discussion
The batch test results showed that water content and emulsion concentration are critical controlling factors, and the removal of lindane and DDT was 99.7% and 88.9%, respectively. A single operation of ISPIE removed 52.9% and 31.5% of DDT and lindane, respectively, and the difference is probably due to the log
K
OW
. The best parameter combination was employed in the sandbox test and the best removal rates of DDT and lindane on the 28th day were 78.0 ± 1.2% and 99.7 ± 0.5%, respectively. NGS data results showed that agriculture soil has more abundant and diverse microorganisms than the acclimated sediment culture. NGS analysis showed two cohesive groups were competing against each other in the batch test and complex interactions existed in the sandbox test.
Conclusions
These results suggest that ISPIE/BiRD is a highly viable remediation option for rice paddy farming lands contaminated by highly hydrophobic contaminants. ISPIE followed by BiRD can be finished in a 42-day period and is highly suitable for implementation during an annual break of paddy field farming. Some potential strong degraders and complex interactions require more research in the future.
Polyglutamine (polyQ)-expanded mutant ataxin-3 protein, which is prone to misfolding and aggregation, leads to cerebellar neurotoxicity in spinocerebellar ataxia type 3 (SCA3), an inherited PolyQ ...neurodegenerative disease. Although the exact mechanism is unknown, the pathogenic effects of mutant ataxin-3 are associated with dysregulation of transcription, protein degradation, mitochondrial function, apoptosis, and antioxidant potency. In the present study we explored the protective role and possible mechanism of caffeic acid (CA) and resveratrol (Res) in cells and Drosophila expressing mutant ataxin-3. Treatment with CA and Res increased the levels of antioxidant and autophagy protein expression with consequently corrected levels of reactive oxygen species, mitochondrial membrane potential, mutant ataxin-3, and the aggregation of mutant ataxin-3 in SK-N-SH-MJD78 cells. Moreover, in SK-N-SH-MJD78 cells, CA and Res enhanced the transcriptional activity of nuclear factor erythroid-derived-2-like 2 (Nrf2), a master transcription factor that upregulates the expression of antioxidant defense genes and the autophagy gene p62. CA and Res improved survival and motor performance in SCA3 Drosophila. Additionally, the above-mentioned protective effects of CA were also observed in CA-supplemented SCA3 Drosophila. Notably, blockade of the Nrf2 pathway by use of small interfering RNA annulled the health effects of CA and Res on SCA3, which affirmed the importance of the increase in Nrf2 activation by CA and Res. Additional studies are need to dissect the protective role of CA and Res in modulating neurodegenerative progression in SCA3 and other polyQ diseases.
•CA and Res increase antioxidation and autophagy in cell and Fly models of SCA3.•CA and Res increase Nrf2 activation in SK-N-SH-MJD78 cells.•CA and Res increase survival and climbing ability in SCA3 Flies.
Display omitted
The effect of biofilm formation on bacteraemic pneumonia caused by A. baumannii is unknown. We conducted a 4-year multi-center retrospective study to analyze 71 and 202 patients with A. baumannii ...bacteraemic pneumonia caused by biofilm-forming and non-biofilm-forming isolates, respectively. The clinical features and outcomes of patients were investigated. Biofilm formation was determined by a microtitre plate assay. The antimicrobial susceptibilities of biofilm-associated cells were assessed using the minimum biofilm eradication concentration (MBEC) assay. Whole-genome sequencing was conducted to identify biofilm-associated genes and their promoters. Quantitative reverse transcription polymerase chain reaction was performed to confirm the expression difference of biofilm-associated genes. There was no significant difference in the clinical characteristics or the outcomes between patients infected with biofilm-forming and non-biofilm-forming strains. Compared with non-biofilm-forming isolates, biofilm-forming isolates exhibited lower resistance to most antimicrobials tested, including imipenem, meropenem, ceftazidime, ciprofloxacin and gentamicin; however, the MBEC assay confirmed the increased antibiotic resistance of the biofilm-embedded bacteria. Biofilm-associated genes and their promoters were detected in most isolates, including the non-biofilm-forming strains. Biofilm-forming isolates showed higher levels of expression of the biofilm-associated genes than non-biofilm-forming isolates. The biofilm-forming ability of A. baumannii isolates might not be associated with worse outcomes in patients with bacteraemic pneumonia.
Background
Laparoscopic hepatectomy (LH) with oncological R0 resection combined with systemic therapy offers the best chance of cure for colorectal liver metastasis. However, tumors in vicinity of ...major hepatic veins require complex technique. Parenchyma-sparing resection with involved vein resection and peritoneal patch reconstruction could be an efficacious alternative to preserve liver volume for adjuvant chemotherapy and avoid venous congestion of the remnant liver.
1
,
2
Methods
A 64-year-old female, with history of colon cancer, had new diagnosis of liver metastatic tumor of S8 (2.8 cm), which was considering encroached on middle hepatic vein (MHV) with distal part patent. Thus margin-negative, parenchyma-sparing liver resection with involved vein resection and proximal MHV reconstruction was indicated for oncological radicality.
Results
With the patient in modified French position, we dissected falciform ligament and right coronary ligament to expose the crypt between right hepatic vein (RHV) and MHV. Intraoperative ultrasound localized the tumor and resection margin. Parenchymal dissection was performed caudally to cranially, left to right, to ligate dorsal branch of G8 (G8d) and V8 and expose main trunk of MHV. The involved side-wall of MHV was incised after the proximal and distal parts clamped. Peritoneal patch was harvested from falciform ligament to repair MHV side-wall before clamps released. The patient had an uneventful recovery and remained disease-free at 1 year postoperatively with patency of distal MHV by image.
Conclusions
LH with MHV reconstruction by falciform ligament for metastatic lesion is technically demanding but feasible with oncological radicality and volume preservation for adjuvant chemotherapy.
This study aimed to explore trends, in 3 periods, in the intake of energy and macronutrients among Taiwanese older adults.
Study subjects were those aged ≥65 years in the Nutrition and Health Survey ...in Taiwan 1999-2000 as well as the surveys in 2005-2008 and 2013-2016. Twenty-four-hour dietary recall data were obtained. This study used the 3 nutrition survey datasets for 1999-2000, 2005-2008, and 2013-2016, including data on the questionnaire, physical examination, and dietary intakes. Each nutrition survey involved the face-to-face household interview, and individual's dietary intake of carbohydrate, fat, and protein (% of energy) was estimated. Subsequently, intake statuses of the three macronutrients were classified into below, meeting, and above intake categories.
In the 2013-2016 survey, approximately 40% of the older adults had a low intake of energy. The prevalence of older adults with a meeting intake of carbohydrate, fat, and protein have increased from the 1999-2000 to 2013-2016 periods. The prevalence of people having a low intake of carbohydrate declined from the 1999-2000 period to the 2013-2016 period. The prevalence of high fat intake in 2013-2016 was approximately 5% higher than that in 1999-2000. In the 2013-2016 period, the prevalence of low intake of carbohydrate, fat, and protein were 25.9, 24.5, and 4.9%, respectively; moreover, the prevalence of high intake of the aforementioned macronutrients were 38.7, 36.2, and 17.6%, respectively.
Our study provides important evidence on the dietary patterns, as well as their changes over time among Taiwanese older adults. Such information would be useful for health policy makers about the burden of unbalanced diet and for nutrition educators on planning nutrition promotion interventions about well-balanced dietary for the older persons.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
