Isostructural metal-insulator transition in VO2 Lee, D; Chung, B; Shi, Y ...
Science (American Association for the Advancement of Science),
11/2018, Volume:
362, Issue:
6418
Journal Article
Peer reviewed
Separating structure and electrons in VO2Above 341 kelvin—not far from room temperature—bulk vanadium dioxide (VO2) is a metal. But as soon as the material is cooled below 341 kelvin, VO2 turns into ...an insulator and, at the same time, changes its crystal structure from rutile to monoclinic. Lee et al. studied the peculiar behavior of a heterostructure consisting of a layer of VO2 placed underneath a layer of the same material that has a bit less oxygen. In the VO2 layer, the structural transition occurred at a higher temperature than the metal-insulator transition. In between those two temperatures, VO2 was a metal with a monoclinic structure—a combination that does not occur in the absence of the adjoining oxygen-poor layer.Science, this issue p. 1037The metal-insulator transition in correlated materials is usually coupled to a symmetry-lowering structural phase transition. This coupling not only complicates the understanding of the basic mechanism of this phenomenon but also limits the speed and endurance of prospective electronic devices. We demonstrate an isostructural, purely electronically driven metal-insulator transition in epitaxial heterostructures of an archetypal correlated material, vanadium dioxide. A combination of thin-film synthesis, structural and electrical characterizations, and theoretical modeling reveals that an interface interaction suppresses the electronic correlations without changing the crystal structure in this otherwise correlated insulator. This interaction stabilizes a nonequilibrium metallic phase and leads to an isostructural metal-insulator transition. This discovery will provide insights into phase transitions of correlated materials and may aid the design of device functionalities.
This national survey was undertaken to propose the classification of extranodal natural killer (NK)/T-cell lymphoma (NTCL) subtypes and to clarify a clinical heterogeneity.
Two hundred and eighty ...patients newly diagnosed as NTCL were enrolled from 22 Korean medical centers. Two subsets were compared: one involving the upper aerodigestive tract (UAT) and another involving the non-upper aerodigestive tract (NUAT) region, which comprises the skin, gastrointestinal tract, and liver or soft tissues. Clinical prognostic factors, survival outcomes, and independent predictors for survival were compared between each subset.
NUAT-NTCL (59 patients) had significantly higher proportions of disseminated disease, aggressive biologic features, and unfavorable host reactions compared with UAT-NTCL (221 patients). NUAT-NTCL had shortened 5-year overall survival (OS) (22% versus 41%, P = 0.001). Ann Arbor staging, the International Prognostic Index, and the NTCL prognostic index failed to predict the OS of NUAT-NTCL, but did predict the OS in UAT-NTCL. Independent predictors for OS by multivariate analyses differed between each subset. In the NUAT subset, extranodal sites and regional nodes predicted the OS, while Ann Arbor staging, age, performance status, and lactate dehydrogenase level predicted the OS in the UAT subset.
NUAT-NTCL may represent a distinctive disease entity in terms of clinical factors, independent predictors, and survival outcomes.
Paclitaxel is currently only available as an intravenous (i.v.) formulation. DHP107 is a novel oral formulation of lipid ingredients and paclitaxel. DHP107 demonstrated comparable efficacy, safety, ...and pharmacokinetics to i.v. paclitaxel as a second-line therapy in patients with advanced gastric cancer (AGC). DREAM is a multicenter, open-label, prospective, randomized phase III study of patients with histologically/cytologically confirmed, unresectable/recurrent AGC after first-line therapy failure.
Patients were randomized 1:1 to DHP107 (200mg/m2 orally twice daily days 1, 8, 15 every 4weeks) or i.v. paclitaxel (175mg/m2 day 1 every 3weeks). Patients were stratified by Eastern Cooperative Oncology Group performance status, disease status, and prior treatment; response was assessed (Response Evaluation Criteria in Solid Tumors) every 6weeks. Primary end point: non-inferiority of progression-free survival (PFS); secondary end points: overall response rate (ORR), overall survival (OS), and safety. For the efficacy analysis, sequential tests for non-inferiority were carried out, first with a non-inferiority margin of 1.48, then with a margin of 1.25.
Baseline characteristics were balanced in the 236 randomized patients (n=118 per arm). Median PFS (per-protocol) was 3.0 (95% CI 1.7–4.0) months for DHP107 and 2.6 (95% CI 1.8–2.8) months for paclitaxel (hazard ratio HR=0.85; 95% CI 0.64–1.13). A sensitivity analysis on PFS using independent central review showed similar results (HR=0.93; 95% CI 0.70–1.24). Median OS (full analysis set) was 9.7 (95% CI 7.1−11.5) months for DHP107 versus 8.9 (95% CI 7.1–12.2) months for paclitaxel (HR=1.04; 95% CI 0.76–1.41). ORR was 17.8% for DHP107 (CR 4.2%; PR 13.6%) versus 25.4% for paclitaxel (CR 3.4%; PR 22.0%). Nausea, vomiting, diarrhea, and mucositis were more common with DHP107; peripheral neuropathy was more common with paclitaxel. There were only few Grade≥3 adverse events, most commonly neutropenia (42% versus 53%); febrile neutropenia was reported infrequently (5.9% versus 2.5%). No hypersensitivity reactions occurred with DHP107 (paclitaxel 2.5%).
DHP107 as a second-line treatment of AGC was non-inferior to paclitaxel for PFS; other efficacy and safety parameters were comparable. DHP107 is the first oral paclitaxel with proven efficacy/safety for the treatment of AGC.
NCT01839773.
Background
Patients with a previous history of hypersensitivity reaction (HSR) to iodinated contrast media (ICM) are at high risk of the development of HSR to ICM. Many studies have tried to evaluate ...the diagnostic potential of skin tests in this population but have not yet reached a common conclusion. We investigated the role of skin tests in patients with HSR to ICM in terms of positive rate, cross‐reactivity rate, and tolerability to skin test‐negative ICM according to the type of HSR.
Methods
We performed literature searches of the MEDLINE and EMBASE databases and included studies where skin tests were performed in patients with HSR to ICM, with extractable outcomes. Outcomes were pooled using a random‐effects model.
Results
Twenty‐one studies were included. Pooled per‐patient positive rates of skin tests were 17% (95% CI, 10–26%) in patients with immediate HSR, and up to 52% (95% CI, 31–72%) when confined to severe immediate HSR. Among patients with nonimmediate HSR, the positive rate was 26% (95% CI, 15–41%). The pooled per‐patient cross‐reactivity rate was higher in nonimmediate HSR (68%; 95% CI, 48–83%) than that in immediate HSR (39%; 95% CI, 29–50%). Median per‐test cross‐reactivity rates between pairs of ICM were 7% (IQR, 6–9%) in immediate HSR and 38% (IQR, 22–51%) in nonimmediate HSR. Pooled per‐patient recurrence rates of HSR to skin test‐negative ICM were 7% (95% CI, 4–14%) in immediate HSR and 35% (95% CI, 19–55%) in nonimmediate HSR.
Conclusion
Skin tests may be helpful in diagnosing and managing patients with HSR to ICM, especially in patients with severe immediate HSR.
Adjuvant chemotherapy and chemoradiotherapy are some of the standards of care for gastric cancer (GC). The Adjuvant chemoRadioTherapy In Stomach Tumors (ARTIST) 2 trial compares two adjuvant ...chemotherapy regimens and chemoradiotherapy in patients with D2-resected, stage II or III, node-positive GC.
The ARTIST 2 compared, in a 1:1:1 ratio, three adjuvant regimens: oral S-1 (40-60 mg twice daily 4 weeks on/2 weeks off) for 1 year, S-1 (2 weeks on/1 week off) plus oxaliplatin 130 mg/m2 every 3 weeks (SOX) for 6 months, and SOX plus chemoradiotherapy 45 Gy (SOXRT). Randomization was stratified according to surgery type (total or subtotal gastrectomy), pathologic stage (II or III), and Lauren histologic classification (diffuse or intestinal/mixed). The primary endpoint was disease-free survival (DFS) at 3 years; a reduction of 33% in the hazard ratio (HR) for DFS with SOX or SOXRT, when compared with S-1, was considered clinically meaningful. The trial is registered at clinicaltrials.gov (NCT0176146).
A total of 546 patients were recruited between February 2013 and January 2018 with 182, 181, and 183 patients in the S-1, SOX, and SOXRT arms, respectively. Median follow-up period was 47 months, with 178 DFS events observed. Estimated 3-year DFS rates were 64.8%, 74.3%, and 72.8% in the S-1, SOX, and SOXRT arms, respectively. HR for DFS in the control arm (S-1) was shorter than that in the SOX and SOXRT arms: S-1 versus SOX, 0.692 (P = 0.042) and S-1 versus SOXRT, 0.724 (P = 0.074). No difference in DFS was found between SOX and SOXRT (HR 0.971; P = 0.879). Adverse events were as anticipated in each arm, and were generally well-tolerated and manageable.
In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy. The addition of radiotherapy to SOX did not significantly reduce the rate of recurrence after D2 gastrectomy.
•In patients with curatively D2-resected, stage II/III, node-positive GC, adjuvant SOX or SOXRT was effective in prolonging DFS, when compared with S-1 monotherapy.•The addition of radiotherapy to chemotherapy did not significantly reduce the rate of recurrence after D2 gastrectomy.•DFS between patients treated with adjuvant chemotherapy and chemoradiotherapy was similar across all subgroups, including Lauren classification.
We determined the fecal carriage rate of serotype K1
Klebsiella pneumoniae
in healthy Koreans and studied their genetic relationship with liver abscess isolates. We compared the carriage according to ...the country of residence. The stool specimens were collected through health promotion programs in Korea.
K. pneumoniae
strains were selected and tested for K1 by PCR. Serotype K1 isolates were characterized by multilocus sequence typing and pulsed field gel electrophoresis. A total of 248
K. pneumoniae
isolates were obtained from 1,174 Koreans. Serotype K1 was identified in 57 (4.9%), of which 54 (94.7%) were ST 23 and were closely related to the liver abscess isolates. Participants aged >25 years showed a higher fecal carriage rate than those ≤ 25 (
P
= 0.007). The proportion of serotype K1 out of
K. pneumoniae
isolates in foreigners of Korean ethnicity who had lived in other countries was lower compared with those who had lived in Korea (5.6% vs 24.1%,
P
= 0.024). A substantial proportion of Koreans >25 years carries serotype K1
K. pneumoniae
ST23 strains, which are closely related to liver abscess isolates. Differences in carriage rates by country of residence suggests that environmental factors might play an important role in the carriage of this strain.
Summary
Background
Mesenchymal stem cells (MSCs) have multiple immunomodulatory properties and hold therapeutic potential for inflammatory diseases. However, the therapeutic and immunologic effects ...of human umbilical cord blood‐derived MSCs (huMSCs) remain largely unexamined for asthma.
Objective
This study was to investigate the immunomodulatory properties of huMSCs in an ovalbumin (OVA)‐induced murine asthma model.
Methods
Mice were injected intraperitoneally with OVA and an aluminium hydroxide adjuvant. huMSCs were administered via the tail vein (5×105 cells/100 uL) to female BALB/c mice prior to the initial OVA challenge. The effects of huMSCs were assessed by investigating airway hyperresponsiveness, histological changes, inflammatory cell numbers, serum allergen‐specific antibodies, cytokine production in spleen, lung tissue, and bronchoalveolar lavage (BAL) fluid as well as expansion of regulatory T cells.
Results
Administration of huMSCs significantly reduced methacholine bronchial hyperresponsiveness and eosinophil counts in BAL cells. Similarly, there was a significant decrease in serum OVA‐specific IgE and IgG1 levels along with Th2 cytokine production (IL‐4, IL‐5, and IL‐13) in the lung and spleen tissues, whereas increased percentage of regulatory T cells was observed after treatment with huMSCs.
Conclusions
Our results suggest that huMSC treatment reduces OVA‐induced allergic inflammation, which could be mediated by regulatory T cells.
Despite the emerging importance of fibroblast growth factor 21 (FGF21) as a metabolic hormone regulating energy balance, its direct effects on renal function remain unexplored. FGF21 was injected ip ...daily for 12 weeks into db/db mice. Compared with control vehicle injection, FGF21 treatment significantly improved lipid profiles and insulin resistance and resulted in significantly higher serum adiponectin levels. In contrast, serum insulin and 8-isoprostane levels were significantly decreased. Interestingly, FGF21 and its receptor components in the kidneys were found to be significantly up-regulated in db/db mice, which suggests an FGF21-resistant state. FGF21 treatment significantly down-regulated FGF21 receptor components and activated ERK phosphorylation. FGF21 administration also markedly decreased urinary albumin excretion and mesangial expansion and suppressed profibrotic molecule synthesis. Furthermore, FGF21 improved renal lipid metabolism and oxidative stress injury. In cultured renal cells, FGF21 was mainly expressed in mesangial cells, and knockdown of FGF21 expression by stealth small interfering RNA further aggravated high-glucose-induced profibrotic cytokine synthesis in mesangial cells. Our results suggest that FGF21 improves insulin resistance and protects against renal injury through both improvement of systemic metabolic alterations and antifibrotic effects in type 2 diabetic nephropathy. Targeting FGF21 could therefore provide a potential candidate approach for a therapeutic strategy in type 2 diabetic nephropathy.
Aims/hypothesis
Obesity and insulin resistance are associated with low-grade chronic inflammation. Glucagon-like peptide-1 (GLP-1) is known to reduce insulin resistance. We investigated whether GLP-1 ...has anti-inflammatory effects on adipose tissue, including adipocytes and adipose tissue macrophages (ATM).
Methods
We administered a recombinant adenovirus (rAd) producing GLP-1 (rAd-GLP-1) to an
ob/ob
mouse model of diabetes. We examined insulin sensitivity, body fat mass, the infiltration of ATM and metabolic profiles. We analysed the mRNA expression of inflammatory cytokines, lipogenic genes, and M1 and M2 macrophage-specific genes in adipose tissue by real-time quantitative PCR. We also examined the activation of nuclear factor κB (NF-κB), extracellular signal-regulated kinase 1/2 and Jun N-terminal kinase (JNK) in vivo and in vitro.
Results
Fat mass, adipocyte size and mRNA expression of lipogenic genes were significantly reduced in adipose tissue of rAd-GLP-1-treated
ob/ob
mice. Macrophage populations (F4/80
+
and F4/80
+
CD11b
+
CD11c
+
cells), as well as the expression and production of IL-6, TNF-α and monocyte chemoattractant protein-1, were significantly reduced in adipose tissue of rAd-GLP-1-treated
ob/ob
mice. Expression of M1-specific mRNAs was significantly reduced, but that of M2-specific mRNAs was unchanged in rAd-GLP-1-treated
ob/ob
mice. NF-κB and JNK activation was significantly reduced in adipose tissue of rAd-GLP-1-treated
ob/ob
mice. Lipopolysaccharide-induced inflammation was reduced by the GLP-1 receptor agonist, exendin-4, in 3T3-L1 adipocytes and ATM.
Conclusions/interpretation
We suggest that GLP-1 reduces macrophage infiltration and directly inhibits inflammatory pathways in adipocytes and ATM, possibly contributing to the improvement of insulin sensitivity.
Background
Few studies have investigated the incidence of anaphylaxis induced by individual or structurally similar cephalosporins. The aims of the study were to assess the incidence of ...cephalosporin‐induced anaphylaxis and evaluate the clinical efficacy of screening skin tests.
Methods
In this retrospective cohort study, we obtained information on total cephalosporin use and cephalosporin‐induced anaphylaxis in intravenous cephalosporin recipients in 12 general hospitals between 2013 and 2015. Cephalosporins were divided into 4 groups according to similar side‐chain structures. The incidence of cephalosporin‐induced anaphylaxis was assessed for each cephalosporin, cephalosporin generation, and side‐chain group. To verify the efficacy of screening intradermal tests (IDT) with cephalosporin, the 12 hospitals were assigned to the intervention or control group depending on whether they performed screening IDT before the administration of cephalosporins.
Results
We identified 76 cases of cephalosporin‐induced anaphylaxis with 1 123 345 exposures to intravenous cephalosporins (6.8 per 100 000 exposures), and the incidence of fatal anaphylaxis by cephalosporin was 0.1 cases per 100 000 exposures. The highest incidences of anaphylaxis occurred in the ceftizoxime (13.0 cases per 100 000 exposures) and side‐chain group 1 (cefepime, cefotaxime, ceftizoxime, ceftriaxone, and cefuroxime; 9.3 per 100 000). There was no case of anaphylaxis induced by cefoxitin, cefmetazole, cefminox, and cefotiam. The clinical effectiveness of routine screening IDT was not significant (P = .06).
Conclusions
The incidence of cephalosporin‐induced anaphylaxis differed according to individual drugs and side‐chain structure. Screening IDT showed no clinical efficacy at a population level.
Among total 1 140 354 cephalosporin treatment courses from 12 hours hospitals, the incidence of cephalosporin induced anaphylaxis was 6.8 per 100 000 exposures and the related fatality was 1.3%. The incidence of cephalosporin induced anaphylaxis varies with each drug type, and the highest incidences of anaphylaxis occurred in the ceftizoxime (13.0 cases per 100 000 exposures). Screening intradermal tests with cephalosporin failed to show preventive effect on cephalosporin‐induced anaphylaxis.
PDF
