Electronic and thermal transport properties of the metallic antiferromagnet MnSn2

We report the structure, magnetic and electrical/thermal transport properties of the antiferromagnet MnSn₂. Importantly, the existence of the two antiferromagnetic states below T_N2 (∼320 K) is confirmed by magnetism and electrical transport measurements. An unsaturated positive magnetoresistance up to 150% at ∼9 T was observed at 5 K, whereas the magnetoresistance becomes negative in the whole range at high temperatures (T > 74 K). Systematic investigations of the Hall transport and thermoelectric properties reveal that the hole-type carriers are the majority carriers in MnSn₂. The kink around 320 K in the Seebeck coefficient originates from the effect of the antiferromagnetic phase on the band structure, while the pronounced peak around 231 K is attributed to the phonon-drag effect. The results suggest that the spin arrangement plays a vital role in the magnetic, electrical, and thermal transport properties in MnSn₂.

Analyzing Operating Room Utilization in a Private Medical Center in Israel

BACKGROUND

Surgery is a core activity in hospitals. Operating rooms have some of the most important and vital functions in medical centers. The operating rooms and their staff are a valuable infrastructure resource and their availability and preparedness affect human life and quality of care.

OBJECTIVES

To prepare operational suggestions for improving operating room utilization by mapping current working processes in the operating rooms of a large private medical center.

METHODS

Data on 23,585 surgeries performed at our medical center between August 2016 and March 2017 were analyzed by various parameters including utilization, capacity, working hours, and surgery delays.

RESULTS

Average operating room utilization was 79%, while 21% was considered lost operating room time. The two major factors that influenced the lost operating room time were the time intervals between planned usage blocks and the partial utilization of operating room time. We calculated that each percent of utilized operating room time translates into 440 surgeries annually, resulting in a potential annual increase in income.

CONCLUSIONS

Increasing operating room utilization would result in an improvement of operating room availability and an increased number of procedures. Our analysis shows that operating room utilization in the private healthcare system is efficient compared to the public healthcare system in Israel. Therefore the private healthcare system should be treated as a contributing factor to help lower surgery waiting times and release bottlenecks, rather than being perceived as contributing to inequality.

Critical behavior in tetragonal antiperovskite GeNFe3 with a frustrated ferromagnetic state

Tetragonal GeNFe₃ has a second-order ferromagnetic (FM) to paramagnetic transition at 76 K. Our integrated investigations indicate that the ground FM state is frustrated and the tetragonal symmetry is retained below 550 K based on the results of variable temperature X-ray diffraction. Critical behavior was analyzed by a systematic bulk magnetization study. The estimated critical exponents by three different methods (modified Arrott plot, the Kouvel-Fisher method, and critical isotherm analysis) conformably suggest that long-range magnetic coupling described by mean-field (MF) theoretical model is dominant in GeNFe₃. The experimental M-T-H data collapse into two independent branches according to the scaling equations m = f_±(h) with the renormalized magnetization m = ε^-βM(H, ε) and the magnetic field h = Hε^-(β+γ). The exchange distance is estimated as J(r) ∼ r^-4.8 on the basis of the β and γ values, which lies between the long-range MF model (r^-4.5) and the short-range 3D Heisenberg (3DH) model (r^-5). Our results indicate that the competition between local magnetic moments of iron 3d electronic state and itinerant covalent interactions of N-Fe bonds should be responsible for critical behavior in this system.

Anomalous Hall effect in tetragonal antiperovskite GeNFe3 with a frustrated ferromagnetic state

We report observed anomalous Hall effect (AHE) behavior in the antiperovskite compound GeNFe₃ with a tetragonal symmetry.

MicroRNA-449a inhibits cell growth in lung cancer and regulates long noncoding RNA nuclear enriched abundant transcript 1

OBJECTIVE

Lung cancer has become the primary cause of cancer-related death now. New therapies targeting the molecular regulatory machinery were required imperatively. MicroRNAs and long noncoding RNAs can respectively or cooperatively function as oncogenes or tumor suppressor genes in human cancers. The present study identified that miR-449a was down-regulated in tissue of human lung cancer. In this study, we aimed to investigate the function of miR-449a in NL9980 and L9981 lung carcinoma cells lines and the relationship with lncRNA nuclear enriched abundant transcript 1 (NEAT1).

MATERIALS AND METHODS

miR-449a was profiled in several lung carcinoma cell lines by quantitative reverse transcription-polymerase chain reaction RT-PCR. We analyzed the effects of miR-449a overexpression on proliferation, apoptosis and cell cycle in L9981 cells. The regulatory relationship between miR-449a and NEAT1 was predicted in silico and further studied by miR-449a inhibitor and mimics assay.

RESULTS

miR-449a was expressed in four cell lines, which we selected, however miR-449a was in high level in NL9980 and in low level in L9981 (P < 0.05). When the miR-449a was the overexpression in L9981 cells, the cell growth was suppressed, and the apoptosis cells were promoted compared with the control group (P < 0.05). The G1/G0 became longer and S, G2/M became shorter (P < 0.05) by miR-449a overexpression. Further study of the interaction between miR-449a and NEAT1 show that NEAT1 was up-regulated when cells were transfected with miR-449a inhibitor, and NEAT1 was down-regulated when cells transfected with miR-449a mimics.

CONCLUSIONS

Our data indicate that miR-449a may function as a suppressor of lung cancer, and affects the expression of NEAT1 in lung cancer cells.

Multiferroic properties of Bi0.5K0.5TiO3–BiFe1−xCoxO3 (0 ≤ x ≤ 0.2) solid solution

We have successfully prepared a binary lead-free solid-solution of Bi_0.5K_0.5TiO₃–BiFe_1−xCo_xO₃ using a modified Pechini method and investigated the magnetic and ferroelectric properties of Bi_0.5K_0.5TiO₃–BiFe_1−xCo_xO₃ (0 ≤ x ≤ 0.2).

IL-6 secreted by cancer-associated fibroblasts induces tamoxifen resistance in luminal breast cancer

Cancer-associated fibroblasts (CAFs) have been implicated in the development of resistance to anticancer drugs; however, the role and mechanism underlying CAFs in luminal breast cancer (BrCA) tamoxifen resistance are unclear. We found that stromal fibroblasts isolated from the central or peripheral area of BrCA have similar CAF phenotype and activity. In vitro and in vivo experiments showed that CAFs derived from clinical-luminal BrCAs induce tamoxifen resistance through decreasing estrogen receptor-α (ER-α) level when cultured with luminal BrCA cell lines MCF7 and T47D. CAFs promoted tamoxifen resistance through interleukin-6 (IL-6) secretion, which activates Janus kinase/signal transducers and activators of transcription (JAK/STAT3) and phosphatidylinositol 3-kinase (PI3K)/AKT pathways in tumor cells, followed by induction of epithelial-mesenchymal transition and upregulation of E3 ubiquitin ligase anaphase-promoting complex 10 activity, which targeted ER-α degradation through the ubiquitin-proteasome pathway. Inhibition of proteasome activity, IL-6 activity or either the JAK/STAT3 or PI3K/AKT pathways markedly reduced CAF-induced tamoxifen resistance. In xenograft experiments of CAFs mixed with MCF7 cells, CAF-specific IL-6 knockdown inhibited tumorigenesis and restored tamoxifen sensitivity. These findings indicate that CAFs mediate tamoxifen resistance through IL-6-induced degradation of ER-α in luminal BrCAs.Oncogene advance online publication, 9 June 2014; doi:10.1038/onc.2014.158.

Effects of hypoxia/reoxygenation on angiogenic factors and their tyrosine kinase receptors in the rat myocardium

The process of angiogenesis is initiated primarily as a consequence of hypoxic stimulation at the cellular and molecular level. Although several angiogenic growth factors have been identified, at present a detailed understanding of the interplay among inducing stimuli, growth factors, and their respective molecular targets remains to be evaluated. Here we report the effects of progressively increasing durations of moderate hypoxia on the protein expression profiles and tissue distribution patterns of the vascular endothelial growth factor system and the angiopoietin/Tie system in the adult rat myocardium. The relative temporal trends of expression of the various components of these two systems, as well as apparent relationships between Flk-1 and angiopoietin-2 and between Flt-1 and Tie-1, suggest a probable sequence of involvement during myocardial angiogenesis, as proposed in our model. Such relationships may potentially be utilized in formulating strategies for sequential gene therapy to achieve clinically relevant myocardial angiogenesis.

Rippling muscle disease: Evidence for phenotypic and genetic heterogeneity

We describe the clinical features of a family with rippling muscle disease. Muscle stiffness and myalgia were the most prominent symptoms. Muscle rippling, although distinctive, was present in only 6 of the 11 affected family members, whereas persistent muscle contraction to muscle percussion was present in all affected adults. Although this persistent contraction resembled percussion myotonia, it was electrically silent and is therefore more aptly called "percussion contracture." We also observed two clinical features not emphasized in previously reported kindreds: mild but asymptomatic weakness of face or proximal muscles was present in 5 of 11 affected members, and 5 individuals also complained of toe walking after a prolonged period of inactivity, reflecting the disproportionate involvement of the calf muscles. The pedigree suggested autosomal dominant inheritance. Our linkage analysis excluded the region on chromosome 1q identified in a previous linkage study.

Large expansion of the ATTCT pentanucleotide repeat in spinocerebellar ataxia type 10

Spinocerebellar ataxia type 10 (SCA10; MIM 603516; refs 1,2) is an autosomal dominant disorder characterized by cerebellar ataxia and seizures. The gene SCA10 maps to a 3.8-cM interval on human chromosome 22q13-qter (refs 1,2). Because several other SCA subtypes show trinucleotide repeat expansions, we examined microsatellites in this region. We found an expansion of a pentanucleotide (ATTCT) repeat in intron 9 of SCA10 in all patients in five Mexican SCA10 families. There was an inverse correlation between the expansion size, up to 22.5 kb larger than the normal allele, and the age of onset (r2=0.34, P=0.018). Analysis of 562 chromosomes from unaffected individuals of various ethnic origins (including 242 chromosomes from Mexican persons) showed a range of 10 to 22 ATTCT repeats with no evidence of expansions. Our data indicate that the new SCA10 intronic ATTCT pentanucleotide repeat in SCA10 patients is unstable and represents the largest microsatellite expansion found so far in the human genome.

Mapping of a new autosomal dominant spinocerebellar ataxia to chromosome 22

The autosomal dominant cerebellar ataxias (ADCAs) are a clinically and genetically heterogeneous group of disorders. The clinical symptoms include cerebellar dysfunction and associated signs from dysfunction in other parts of the nervous system. So far, five spinocerebellar ataxia (SCA) genes have been identified: SCA1, SCA2, SCA3, SCA6, and SCA7. Loci for SCA4 and SCA5 have been mapped. However, approximately one-third of SCAs have remained unassigned. We have identified a Mexican American pedigree that segregates a new form of ataxia clinically characterized by gait and limb ataxia, dysarthria, and nystagmus. Two individuals have seizures. After excluding all known genetic loci for linkage, we performed a genomewide search and identified linkage to a 15-cM region on chromosome 22q13. A maximum LOD score of 4.3 (recombination fraction 0) was obtained for D22S928 and D22S1161. This distinct form of ataxia has been designated "SCA10." Anticipation was observed in the available parent-child pairs, suggesting that trinucleotide-repeat expansion may be the mutagenic mechanism.

Clinical and genetic analysis of a distinct autosomal dominant spinocerebellar ataxia

OBJECTIVE

To characterize a distinct form of spinocerebellar ataxia (SCA) clinically and genetically.

BACKGROUND

The SCAs are a genetically heterogeneous group of neurodegenerative disorders affecting the cerebellum and its connections. The mutations for SCA1, 2, 3, 6, and 7 have been identified and shown to be due to expansion of a CAG repeat in the coding region of these genes. Two additional SCA loci on chromosomes 16 and 11 have been designated SCA4 and SCA5. However, up to 20% of individuals with autosomal dominant forms of ataxias cannot be assigned any of these genotypes, implying the presence of other unidentified genes that may be involved in the development of ataxia.

METHODS

We ascertained and clinically characterized a six-generation pedigree segregating an autosomal dominant trait for SCA. We performed direct mutation analysis and linkage analysis for all known SCA loci.

RESULTS

The mutation analysis excludes SCA1, 2, 3, 6, and 7, and genetic linkage analysis excludes SCA4 and SCA5 (multipoint location scores < -2 across the candidate region). Clinical analysis of individuals in this family shows that all affected members have dysarthria, gait and limb ataxia, and nystagmus. No individuals have major brainstem or long-tract findings. Analysis of age at disease onset through multiple generations suggests anticipation.

CONCLUSION

This pedigree represents a genetically distinct form of SCA with a phenotype characterized by predominantly cerebellar symptoms and signs.