Superconductivity in (Ba,K)SbO3 Kim, Minu; McNally, Graham M.; Kim, Hun-Ho ...
Nature materials,
06/2022, Volume:
21, Issue:
6
Journal Article
Peer reviewed
Open access
Abstract
(Ba,K)BiO
3
constitute an interesting class of superconductors, where the remarkably high superconducting transition temperature
T
c
of 30 K arises in proximity to charge density wave order. ...However, the precise mechanism behind these phases remains unclear. Here, enabled by high-pressure synthesis, we report superconductivity in (Ba,K)SbO
3
with a positive oxygen–metal charge transfer energy in contrast to (Ba,K)BiO
3
. The parent compound BaSbO
3−
δ
shows a larger charge density wave gap compared to BaBiO
3
. As the charge density wave order is suppressed via potassium substitution up to 65%, superconductivity emerges, rising up to
T
c
= 15 K. This value is lower than the maximum
T
c
of (Ba,K)BiO
3
, but higher by more than a factor of two at comparable potassium concentrations. The discovery of an enhanced charge density wave gap and superconductivity in (Ba,K)SbO
3
indicates that strong oxygen–metal covalency may be more essential than the sign of the charge transfer energy in the main-group perovskite superconductors.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract
Magnonic devices operating at terahertz frequencies offer intriguing prospects for high-speed electronics with minimal energy dissipation However, guiding and manipulating terahertz magnons ...via external parameters present formidable challenges. Here we report the results of magnetic Raman scattering experiments on the antiferromagnetic spin-orbit Mott insulator Sr
2
IrO
4
under uniaxial stress. We find that the energies of zone-center magnons are extremely stress sensitive: lattice strain of 0.1% increases the magnon energy by 40%. The magnon response is symmetric with respect to the sign of the applied stress (tensile or compressive), but depends strongly on its direction in the IrO
2
planes. A theory based on coupling of the spin-orbit-entangled iridium magnetic moments to lattice distortions provides a quantitative explanation of the Raman data and a comprehensive framework for the description of magnon-lattice interactions in magnets with strong spin-orbit coupling. The possibility to efficiently manipulate the propagation of terahertz magnons via external stress opens up multifold design options for reconfigurable magnonic devices.
Following resection of glioblastoma (GBM), microscopic remnants of the GBM tumor remaining in nearby tissue cause tumor recurrence more often than for other types of tumors, even after gross-total ...resection (GTR). Although surgical oncologists traditionally resect some of the surrounding normal tissue, whether further removal of nearby tissue may improve survival in GBM patients is unknown. In this single-center retrospective study, the authors assessed whether lobectomy confers a survival benefit over GTR without lobectomy when treating GBMs in the noneloquent area.
The authors selected 40 patients who had undergone GTR of a histopathologically diagnosed isocitrate dehydrogenase (IDH)-wild type GBM in the right frontal or temporal lobe and divided the patients into 2 groups according to whether GTR of the tumor involved lobectomy, defined as a supratotal resection (SupTR group, n = 20) or did not (GTR group, n = 20). Progression-free survival (PFS), overall survival (OS), and Karnofsky Performance Status (KPS) scores were compared between groups (p ≤ 0.05 for statistically significant differences).
The median postoperative PFS times for each group were as follows: GTR group, 11.5 months (95% CI 8.8-14.2) and SupTR group, 30.7 months (95% CI 4.3-57.1; p = 0.007). The median postoperative OS times for each group were as follows: GTR group, 18.7 months (95% CI 14.3-23.1) and SupTR group, 44.1 months (95% CI 25.1-63.1; p = 0.040). The mean postoperative KPS scores (GTR, 76.5; SupTR, 77.5; p = 0.904) were not significantly different. In multivariate analysis, survival for the SupTR group was significantly longer than that for the GTR group in terms of both PFS (HR 0.230; 95% CI 0.090-0.583; p = 0.002) and OS (HR 0.247; 95% CI 0.086-0.704; p = 0.009).
In cases of completely resectable, noneloquent-area GBMs, SupTR provides superior PFS and OS without negatively impacting patient performance.
This study was conducted to assess whether levetiracetam (LEV) affects the survival of patients with glioblastoma (GBM) treated with concurrent temozolomide (TMZ) chemotherapy. To this end, from 2004 ...to 2016, 322 patients with surgically resected and pathologically confirmed isocitrate dehydrogenase (IDH)-wildtype GBM who received TMZ-based chemoradiotherapy were analysed. The patients were divided into two groups based on whether LEV was used as an anticonvulsant both at the time of surgery and the first visit thereafter. The median overall survival (OS) and progression-free survival (PFS) were compared between the groups. The OS was 21.1 and 17.5 months in the LEV (+) and LEV (-) groups, respectively (P = 0.003); the corresponding PFS was 12.3 and 11.2 months (P = 0.017). The other prognostic factors included age, extent of resection, O
-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, and Karnofsky Performance Status (KPS) score. The multivariate analysis showed age (hazard ratio HR, 1.02; P < 0.001), postoperative KPS score (HR 0.99; P = 0.002), complete tumour resection (HR 0.52; P < 0.001), MGMT promoter methylation (HR 0.75; P < 0.001), and LEV use (HR 0.72; P = 0.011) were significantly associated with OS. In conclusion, LEV use was associated with prolonged survival in patients with GBM treated with concurrent TMZ chemoradiotherapy.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Resident cancer cells with stem cell-like features induce drug tolerance, facilitating survival of glioblastoma (GBM). We previously showed that strategies targeting tumor bioenergetics present a ...novel emerging avenue for treatment of GBM. The objective of this study was to enhance the therapeutic effects of dual inhibition of tumor bioenergetics by combination of gossypol, an aldehyde dehydrogenase inhibitor, and phenformin, a biguanide compound that depletes oxidative phosphorylation, with the chemotherapeutic drug, temozolomide (TMZ), to block proliferation, stemness, and invasiveness of GBM tumorspheres (TSs). Combination therapy with gossypol, phenformin, and TMZ induced a significant reduction in ATP levels, cell viability, stemness, and invasiveness compared to TMZ monotherapy and dual therapy with gossypol and phenformin. Analysis of differentially expressed genes revealed up-regulation of genes involved in programmed cell death, autophagy, and protein metabolism and down-regulation of those associated with cell metabolism, cycle, and adhesion. Combination of TMZ with dual inhibitors of tumor bioenergetics may, therefore, present an effective strategy against GBM by enhancing therapeutic effects through multiple mechanisms of action.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract
BACKGROUND
Endoscopic transorbital approach (ETOA) has been proposed as a minimally invasive technique for the treatment of skull base lesions located around mesial temporal lobe (MTL), ...mostly extra-axial pathology.
OBJECTIVE
To explore the feasibility of ETOA in accessing intraparenchymal MTL with cadaveric specimens and describe our initial clinical experience of ETOA for intra-axial lesions in MTL.
METHODS
Anatomic dissections were performed in 4 adult cadaveric heads using a 0° endoscope. First, a stepwise anatomical investigation of ETOA to intraparenchymal MTL was explored. Then, ETOA was applied clinically for 7 patients with intra-axial lesions in MTL, predominantly high-grade gliomas (HGGs) and low-grade gliomas (LGGs).
RESULTS
The extradural stage of ETOA entailed a superior eyelid incision followed by orbital retraction, drilling of orbital roof, greater and lesser wing of sphenoid bone, and cutting of the meningo-orbital band. For the intradural stage, the brain tissue medial to the occipito-temporal gyrus was aspirated until the temporal horn was opened. The structures of MTL could be aspirated selectively in a subpial manner without injury to the neurovascular structures of the ambient and sylvian cisterns, and the lateral neocortex. After cadaveric validation, ETOA was successfully performed for 4 patients with HGGs and 3 patients with LGGs. Gross total resection was achieved in 6 patients (85.7%) without significant surgical morbidities including visual field deficits.
CONCLUSION
ETOA provides a logical line of access for intra-axial lesions in MTL. The safe and natural surgical trajectory of ETOA can spare brain retraction, neurovascular injury, and disruption of the lateral neocortex.
Introduction Brain metastasis in differentiated thyroid cancer (DTC) is rare (frequency < 1%) and has a poor prognosis. Treatment strategies for brain metastasis are not well established. Objectives ...We conducted a retrospective analysis to identify predictive factors for patient outcomes and verify surgical indications for patients with brain metastasis and DTC. Methods The study included 34 patients with pathologically confirmed DTC with brain metastasis from March 2008 to November 2020. The associations between overall survival (OS) and clinical factors were evaluated. Cox regression analysis was used to determine the relationship between clinical factors and OS. To assess the survival benefit of craniotomy, Kaplan–Meier survival analysis was performed for each variable whose statistical significance was determined by Cox regression analysis. Results The median OS of the entire patient sample was 11.4 months. Survival was affected by the presence of lung metastasis (P = 0.033) and the number of brain metastases (n > 3) (P = 0.039). Only the subgroup with the number of brain metastases ≤3 showed statistical significance in the subgroup analysis of survival benefit following craniotomy (P = 0.048). Conclusions The number of brain metastases and the existence of lung metastasis were regarded more essential than other clinical factors in patients with DTC in this study. Furthermore, craniotomies indicated a survival benefit only when the number of brain metastases was ≤3. This finding could be beneficial in determining surgical indications in thyroid cancer with brain metastasis.
Background
Delirium is characterized by acute brain dysfunction. Although delirium significantly affects the quality of life of patients with brain metastases, little is known about delirium in ...patients who undergo craniotomy for brain metastases. This study aimed to identify the factors influencing the occurrence of delirium following craniotomy for brain metastases and determine its impact on patient prognosis.
Method
A total of 153 patients who underwent craniotomy for brain metastases between March 2013 and December 2020 were evaluated for clinical and radiological factors related to the occurrence of delirium. Statistical analysis was conducted by dividing the patients into two groups based on the presence of delirium, and statistical significance was confirmed by adjusting the clinical characteristics of the patients with brain metastases using propensity score matching (PSM). The effect of delirium on patient survival was subsequently evaluated using Kaplan–Meier analysis.
Results
Of 153 patients, 14 (9.2%) had delirium. Age (
P
= 0.002), sex (
P
= 0.007), and presence of postoperative hematoma (
P
= 0.001) were significantly different between the delirium and non-delirium groups. When the matched patients (14 patients in each group) were compared using PSM, postoperative hematoma showed a statistically significant difference (
P
= 0.036) between the delirium and non-delirium groups. Kaplan–Meier survival analysis revealed that the delirium group had poorer prognosis (log-rank score of 0.0032) than the non-delirium group.
Conclusion
In addition to the previously identified factors, postoperative hematoma was identified as a strong predictor of postoperative delirium. Also, the negative impact of delirium on patient prognosis including low survival rate was confirmed.
PDF
