58 research outputs found
Doping-dependent superconducting physical quantities of K-doped BaFeAs obtained through infrared spectroscopy
We investigated four single crystals of K-doped BaFeAs (Ba-122),
BaKFeAs with = 0.29, 0.36, 0.40, and 0.51, using
infrared spectroscopy. We explored a wide variety of doping levels, from under-
to overdoped. We obtained the superfluid plasma frequencies
() and corresponding London penetration depths
() from the measured optical conductivity spectra. We
also extracted the electron-boson spectral density (EBSD) functions using a
two-parallel charge transport channel approach in the superconducting (SC)
state. From the extracted EBSD functions, the maximum SC transition
temperatures () were determined using a generalized
McMillan formula and the SC coherence lengths () were
calculated using the timescales encoded in the EBSD functions and reported
Fermi velocities. We identified some similarities and differences in the
doping-dependent SC quantities between the K-doped Ba-122 and the hole-doped
cuprates. We expect that the various SC quantities obtained across the wide
doping range will provide helpful information for establishing the microscopic
pairing mechanism in Fe-pnictide superconductors.Comment: 16 pages, 4 figures, 1 tabl
Role of Immunohistochemistry in Fine Needle Aspiration and Core Needle Biopsy of Thyroid Nodules
Objectives Immunohistochemistry (IHC) has been used for the diagnosis of indeterminate results in fine needle aspiration (FNA) of thyroid nodules. However, the role of IHC in core needle biopsy (CNB) is not clear and the efficacy of testing for molecular markers following CNB has not been evaluated. The aim of this study is to compare the role of IHC staining in CNB with that in FNA when examining thyroid nodules and to compare the sensitivity and usefulness of different molecular markers. Methods Consecutive cases of thyroid FNA and CNB accompanied by IHC from 2004 to 2014 were included in this study with retrospective review of medical record. The rate of remaining nondiagnostic result (unsatisfactory, atypia of undetermined significance or follicular lesion of undetermined significance [AUS/FLUS]) and rate of strong expression of each molecular marker according to the diagnosis were evaluated. Results IHC was more frequently performed in CNB with multiple molecular markers compared to FNA (38.1% vs. 2.8%, 3 or 4 markers [Gal-3, HBME-1, CK19, and CD56] vs. 1 marker [Gal-3]). In the CNB group, 11.3% remained as AUS/FLUS after IHC, and the rate remaining nondiagnostic was significantly less than in the FNA group (42.9%). Gal-3 and CK19 showed higher specificity and expressed mainly in conventional type of papillary carcinoma and HBME-1 showed higher sensitivity for the diagnosis of carcinoma with expression in both conventional type and follicular variant papillary thyroid carcinoma. Conclusion With these data, we could conclude that IHC was more effective following CNB than following FNA
Systematic analysis of Mendelian disease-associated gene variants reveals new classes of cancer-predisposing genes
Background
Despite the acceleration of somatic driver gene discovery facilitated by recent large-scale tumor sequencing data, the contribution of inherited variants remains largely unexplored, primarily focusing on previously known cancer predisposition genes (CPGs) due to the low statistical power associated with detecting rare pathogenic variant-phenotype associations.
Methods
Here, we introduce a generalized log-regression model to measure the excess of pathogenic variants within genes in cancer patients compared to control samples. It aims to measure gene-level cancer risk enrichment by collapsing rare pathogenic variants after controlling the population differences across samples.
Results
In this study, we investigate whether pathogenic variants in Mendelian disease-associated genes (OMIM genes) are enriched in cancer patients compared to controls. Utilizing data from PCAWG and the 1,000 Genomes Project, we identify 103 OMIM genes demonstrating significant enrichment of pathogenic variants in cancer samples (FDR 20%). Through an integrative approach considering three distinct properties, we classify these CPG-like OMIM genes into four clusters, indicating potential diverse mechanisms underlying tumor progression. Further, we explore the function of PAH (a key metabolic enzyme associated with Phenylketonuria), the gene exhibiting the highest prevalence of pathogenic variants in a pan-cancer (1.8%) compared to controls (0.6%).
Conclusions
Our findings suggest a possible cancer progression mechanism through metabolic profile alterations. Overall, our data indicates that pathogenic OMIM gene variants contribute to cancer progression and introduces new CPG classifications potentially underpinning diverse tumorigenesis mechanisms.This research was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI18C1876) and the National Research Foundation of Korea (NRF; grant number: 2021R1A2C3005360). This work was also supported by the Seoul National University Hospital Research Fund (grant number: 1120190020 and 03–2020-0380) and the computing resources by Global Science experimental Data Hub Center (GSDC) and Korea Research Environment Open NETwork (KREONET). SHL was supported by Future Medicine 20*30 Project of the Samsung Medical Center (SMX1230041). SP was supported by the project PID2019-109571RA-I00 funded by the Agencia Estatal de Investigación (AEI/10.13039/501100011033), Ministerio de Ciencia e Innovación; Ramon y Cajal Gran RYC2021-034415-I funded by the MCIN/AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR; and the Severo Ochoa Centres of Excellence Programme to the CNIO CEX2019-000891-S funded by the MCIN/AEI/10.13039/50110001103
Genetic assessment of pathogenic germline alterations in lysosomal genes among Asian patients with pancreatic ductal adenocarcinoma
Background
Lysosomes are closely linked to autophagic activity, which plays a vital role in pancreatic ductal adenocarcinoma (PDAC) biology. The survival of PDAC patients is still poor, and the identification of novel genetic factors for prognosis and treatment is highly required to prevent PDAC-related deaths. This study investigated the germline variants related to lysosomal dysfunction in patients with PDAC and to analyze whether they contribute to the development of PDAC.
Methods
The germline putative pathogenic variants (PPV) in genes involved in lysosomal storage disease (LSD) was compared between patients with PDAC (n = 418) and healthy controls (n = 845) using targeted panel and whole-exome sequencing. Furthermore, pancreatic organoids from wild-type and KrasG12D mice were used to evaluate the effect of lysosomal dysfunction on PDAC development. RNA sequencing (RNA-seq) analysis was performed with established PDAC patient-derived organoids (PDOs) according to the PPV status.
Results
The PPV in LSD-related genes was higher in patients with PDAC than in healthy controls (8.13 vs. 4.26%, Log2 OR = 1.65, P = 3.08 × 10–3). The PPV carriers of LSD-related genes with PDAC were significantly younger than the non-carriers (mean age 61.5 vs. 65.3 years, P = 0.031). We further studied a variant of the lysosomal enzyme, galactosylceramidase (GALC), which was the most frequently detected LSD variant in our cohort. Autophagolysosomal activity was hampered when GALC was downregulated, which was accompanied by paradoxically elevated autophagic flux. Furthermore, the number of proliferating Ki-67+ cells increased significantly in pancreatic organoids derived from Galc knockout KrasG12D mice. Moreover, GALC PPV carriers tended to show drug resistance in both PDAC cell line and PDAC PDO, and RNA-seq analysis revealed that various metabolism and gene repair pathways were upregulated in PDAC PDOs harboring a GALC variant.
Conclusions
Genetically defined lysosomal dysfunction is frequently observed in patients with young-onset PDAC. This might contribute to PDAC development by altering metabolism and impairing autophagolysosomal activity, which could be potentially implicated in therapeutic applications for PDAC.This work was supported by the National Research Foundation of Korea funded by the Korean Government (MSIT) (Grant No. NRF-2021R1A2C3005360) (YK) and the Ministry of Health & Welfare, Republic of Korea (Grant No. HI18C1876) (SSY). This study was supported by the Future Medicine 20 × 30 Project of the Samsung Medical Center (Grant No. SMX1230041, SMO1230021) and a Samsung Medical Center Research and Development Grant (Grant No. SMO1230661) (JKP)
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Recent Progress and Challenges of Electron Transport Layers in Organic–Inorganic Perovskite Solar Cells
Organic–inorganic perovskites are crystalline light absorbers which are gaining great attraction from the photovoltaic community. Surprisingly, the power conversion efficiencies of these perovskite solar cells have rapidly increased by over 25% in 2019, which is comparable to silicon solar cells. Despite the many advances in efficiency, there are still many areas to be improved to increase the efficiency and stability of commercialization. For commercialization and enhancement of applicability, the development of electron transport layer (ETL) and its interface for low temperature processes and efficient charge transfer are very important. In particular, understanding the ETL and its interface is of utmost importance, and when this understanding has been made enough, excellent research results have been published that can improve the efficiency and stability of the device. Here, we review the progress of perovskite solar cells. Especially we discuss recent important development of perovskite deposition method and its engineering as well as the electron transport layer
Identification of strontium substitution mechanism in hematite via calcium solution
Nonradioactive strontium (Sr) are produced as a result of radioactive decay of heavier elements such as uranium and thorium. Nonradioactive Sr shares physicochemical similarities with Ca and can replace it during bone formation, which may cause bone cancer in humans. Hence, concerning the potential hazards associated with strontium, it is imperative to eliminate it. The present study aimed to investigate the removal mechanisms of hematite-adsorbed strontium by calcium solution. Strontium was adsorbed to hematite at pH 8 and 10 and washed with calcium solution. X-ray absorption near-edge structure (XANES), extended X-ray absorption fine structure (EXAFS), scanning electron microscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (after Ca washing) were performed on the samples before and after washing. Analyses and fitting by XANES and EXAFS confirmed the formation of an inner-sphere complex of strontium at pH 10. The XRD spectra showed that SrCO3 and SrFe2O4 formed at pH 8 and 10, respectively. After washing with the calcium solution, strontium was directly substituted to form CaCO3 and CaFe2O4. The X-ray photoelectron spectroscopy results provided a systematic analysis of the proportions of hematite and strontium, confirming the substitution of strontium with calcium. This substitution could be attributed to the physicochemical similarities between calcium and strontium. This study confirms the substitution of Sr with Ca, highlighting the physicochemical similarity of the Sr and Ca that facilitates substitution reactions.N
A 1.3pJ/b Inductive Coupling Transceiver with Adaptive Gain Control for Cm-range 50Mbps Data Communication
A 1.3pJ/b inductive coupling transceiver is proposed for Cm-range multimedia data transmission in mobile device applications. Its Transmission Time Control (TTC) scheme and Adaptive Gain Control (AGC) scheme reduce the energy consumption below to 1.3pJ/b. Inductor with self-resonance frequency above 200MHz achieves the data rate over 50Mbps. The receiver sensitivity can be enhanced to increase the communication distance up to 7cm by relative magnitude comparison between two nodes of the receiver inductor. The transceiver consumes only 65 mu W in total with 1V supply.N
A Low-Energy Inductive Coupling Transceiver With Cm-Range 50-Mbps Data Communication in Mobile Device Applications
A low-energy inductive coupling transceiver is proposed for Cm-range multimedia data transmission in mobile device applications. The Transmission Time Control (TTC) scheme is proposed to reduce the transmitter energy consumption to 0.475 pJ/b, and the Adaptive Gain Control (AGC) scheme is adopted to make the receiver energy consumption be 0.825 pJ/b. The planar-type inductor with self-resonance frequency of about 200 MHz fabricated on the flexible substrate achieves a data rate over 50 Mbps. To compensate for the weakly coupled channel, the receiver sensitivity is enhanced by the differential detection method (DDM) of the nodal voltages across the receiver inductor. With this method, the communication distance is increased up to 7 cm, and channel misalignment tolerance is enhanced up to 2 cm. The proposed transceiver is implemented within 1.5 x 2.37 mm(2) in 0.18-mu m CMOS process and operates with 1-V supply.N
Dye-Sensitized Solar Cells Employing Doubly or Singly Open-Ended TiO2 Nanotube Arrays: Structural Geometry and Charge Transport
We systematically investigated the charge transport properties of doubly or singly open-ended TiO2 nanotube arrays (DNT and SNT, respectively) for their utility as electrodes in dye-sensitized solar cells (DSCs). The SNT or DNT arrays were transferred in a bottom-up (B-up) or top-up (T-up) configuration onto a fluorine-doped tin oxide (FTO) substrate onto which had been deposited a 2 mu m thick TiO2 nanoparticle (NP) interlayer. This process yielded four types of DSCs prepared with SNTs (B-up or T-up) or DNT (B-up or T-up). The photovoltaic performances of these DSCs were analyzed by measuring the dependence of the charge transport on the DSC geometry. High resolution scanning electron microscopy techniques were used to characterize the electrode cross sections, and electrochemical impedance spectroscopy was used to characterize the electrical connection at the interface between the NT array and the TiO2 NP interlayer. We examined the effects of decorating the DNT or SNT arrays with small NPs (sNP@DNT and sNP@SNT, respectively) in an effort to increase the extent of dye loading. The DNT arrays decorated with small NPs performed better than the decorated SNT arrays, most likely because the Ti(OH)(4) precursor solution flowed freely into the array through the open ends of the NTs in the DNT case but not in the SNT case. The sNP@DNT based DSC exhibited a better PCE (10%) compared to the sNP@SNT-based DSCs (6.8%) because the electrolyte solution flow was not restricted, direct electron transport though the NT arrays was possible the electrical connection at the interface between the NT array and the TiO2 NP interlayer was good, and the array provided efficient light harvesting.X111615sciescopu
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