Dirac nodal surfaces and nodal lines in ZrSiS

Topological semimetals are characterized by symmetry-protected band crossings, which can be preserved in different dimensions in momentum space, forming zero-dimensional nodal points, one-dimensional nodal lines, or even two-dimensional nodal surfaces. Materials harboring nodal points and nodal lines have been experimentally verified, whereas experimental evidence of nodal surfaces is still lacking. Here, using angle-resolved photoemission spectroscopy (ARPES), we reveal the coexistence of Dirac nodal surfaces and nodal lines in the bulk electronic structures of ZrSiS. As compared with previous ARPES studies on ZrSiS, we obtained pure bulk states, which enable us to extract unambiguously intrinsic information of the bulk nodal surfaces and nodal lines. Our results show that the nodal lines are the only feature near the Fermi level and constitute the whole Fermi surfaces. We not only prove that the low-energy quasiparticles in ZrSiS are contributed entirely by Dirac fermions but also experimentally realize the nodal surface in topological semimetals.

Abstract PD9-05: The importance of the metastatic biopsy: Clinical and translational relevance in a real world series of patients with metastatic breast cancer

Background

Metastatic breast cancer (MBC) is a heterogeneous disease, whose clinical course and prognosis may be unpredictable, creating significant uncertainty for patients and their families. Heterogeneity is breast cancer subtypes is now well recognized as a potential reason for treatment resistance. Sampling metastatic sites at the point of diagnosis or upon progression, when safe, is recommended to better guide therapy.

Purpose

This study evaluated patients currently undergoing treatment for MBC in the clinic to determine the clinical and translational significance of a metastatic sample.

Methods

Patients currently undergoing treatment for MBC at the Olivia Newton John Centre were identified. Data was collected on patient demographics, clinicopathological information, treatment and duration of response. Translational research tissue was collected, with consent, for DNA and RNA analysis.

Results

Between January 2017 and May 2018 111 patients were identified. The mean age of MBC diagnosis was 60 years (range 30-87), with a mean follow up time of 2.4 years (range 0.8-16). Fifteen patients died during the study period. Sixty-seven (60%) patients were initially treated for early breast cancer (EBC), with a median disease free interval (DFI) 4.7 years. Half (51%) these patients relapsed after five years.

At MBC diagnosis, multiple sites of disease were identified including bone, visceral, brain, nodal and skin/chest wall disease. Bone only disease was common (25%), whereas brain disease was rare overall (9%). Metastatic tissue was collected in 67 (60%) patients, where up to four different sites were biopsied. The most commonly biopsied site was bone (n=21), followed by soft tissue (n=20), chest wall/skin disease (n=12), liver (n=9), lung (n=8) and brain (n=8). Serous disease was collected in 16 patients, including pleural, pericardial, ascitic and cerebrospinal fluid.

Based on the EBC subtype (n=67), 70% had luminal disease, 19% had Her2 positive disease and 7% had TNBC. However, based on a metastatic biopsy (n=67), only 61% of patients had luminal disease, 21% had HER2 positive, and 18% had TNBC. Paired EBC and MBC samples were available in 48 patients, with significant change in breast cancer subtype demonstrated in 12 of these patients (25%). The most common change was a loss in ER staining, which included 6 patients from ER positive, HER2 negative to TNBC and three patients who became ER negative but remained HER2 positive. Molecular profiling was performed thus far on 8 samples at the single cell and bulk level. These results highlight a large level of inter- and intra-tumoral heterogeneity, and may result in a better understanding of the molecular pathways specifically deregulated in patients at the point of progression.

Conclusion

In this single institution series of patients with MBC, over half of the cohort underwent at least one metastatic biopsy. Strikingly, a quarter of patients demonstrated a change in their breast cancer subtype, which directly guided subsequent therapy. Metastatic tissue can provide vital information to inform treatment decisions, which may be guided by translational laboratories having access to fresh tissue at the point of metastatic diagnosis or disease progression.

Citation Format: Yeo B, Molinaro T, Merino D, Berthelet J, Pouliot N, Fang C, Bell C, Anderson R. The importance of the metastatic biopsy: Clinical and translational relevance in a real world series of patients with metastatic breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD9-05.

Clinical and genetic features of Chinese patients with lichen and macular primary localized cutaneous amyloidosis

BACKGROUND

Primary localized cutaneous amyloidosis (PLCA) is a chronic pruritic skin disorder. The genetic basis of familial (f)PLCA involves mutations in the oncostatin M receptor (OSMR) and interleukin-31 receptor A (IL31RA) genes, but the disease pathophysiology is not fully understood.

AIM

To investigate the OSMR mutation spectrum in patients with sporadic (s)PLCA/fPLCA, lichen/macular PLCA in mainland China.

METHODS

This study was carried out on 64 patients with sPLCA, along with 36 with fPLCA and 10 unaffected individuals collected from 23 unrelated Chinese families. Genomic DNA was extracted from peripheral blood samples. Mutation screening of 17 OSMR exons was performed by Sanger sequencing.

RESULTS

PLCA lesions are typically localized to the shins, forearm and back. Sequence analysis of OSMR exons demonstrated that the OSMR missense mutation rate in patients with fPLCA (63.89%) was significantly higher than that in patients with sPLCA (34.38%). The male/female ratio of patients carrying a homozygous OSMR mutation (0.29) was significantly lower than that of patients carrying a heterozygous OSMR mutation (1.08; P < 0.05) and of patients with wildtype OSMR (1.75; P < 0.01). Age of onset of PLCA with OSMR homozygous mutation (median age 20 years) was earlier than that of PLCA with OSMR heterozygous mutation (median age 32 years; P < 0.01) or PLCA with wildtype genotype (median age 32 years; P < 0.01).

CONCLUSION

The present data indicate OSMR mutations as not only the main cause of fPLCA, but also the potential source of the pathogenesis of sPLCA, although the exact molecular mechanism remains unknown.

Spin-orbit torque switching in a T-type magnetic configuration with current orthogonal to easy axes

Different symmetry breaking ways determine various magnetization switching modes driven by spin–orbit torques (SOT). For instance, an applied or effective field parallel to applied current is indispensable to switch magnetization with perpendicular anisotropy by SOT. Besides of this mode, here we experimentally demonstrate a distinct field-free switching mode in a T-type magnetic system with structure of MgO/CoFeB/Ta/CoFeB/MgO where a perpendicular layer with tilted easy axis was coupled to an in-plane layer with a uniaxial easy axis. Current was applied orthogonal to both easy axes and thus also normal to an in-plane effective field experienced by the perpendicular layer. Dynamic calculation shows perpendicular layer could be switched at the same time as the in-plane layer is switched. These field-free switching modes realized in the same T-type magnetic system might expedite the birth of multi-state spin memories or spin logic devices which could be operated by all electric manners.

Spin-orbit torque (SOT) induced magnetization switching facilitates all electric multi-state spin memories and spin logic devices. Here the authors show a new SOT field-free switching mode where the perpendicular layer with tilted easy axis is coupled to an in-plane layer with a uniaxial easy axis.

Metabolic GWAS-based dissection of genetic bases underlying the diversity of plant metabolism

Plants have served as sources providing humans with metabolites for food and nutrition, biomaterials for living, and treatment for pain and disease. Plants produce a huge array of metabolites, with an immense diversity at both the population and individual levels. Dissection of the genetic bases for metabolic diversity has attracted increasing research attention. The concept of genome-wide association study (GWAS) was extended to studies on the diversity of plant metabolome that benefitted from the development of mass-spectrometry-based analytical systems and genome sequencing technologies. Metabolic genome-wide association study (mGWAS) is one of the most powerful tools for global identification of genetic determinants for diversity of plant metabolism. Recently, mGWAS has been performed for various species with continuous improvements, providing deeper insights into the genetic bases of metabolic diversity. In this review, we discuss fully the achievements to date and remaining challenges that are associated with both mGWAS and mGWAS-based multi-dimensional analysis. We begin with a summary of GWAS and its development based on statistical methods and populations. As variation in targeted traits is essential for GWAS, we review metabolic diversity and its rise at both the population and individual levels. Subsequently, the application of mGWAS for plants and its corresponding achievements are fully discussed. We address the current knowledge on mGWAS-based multi-dimensional analysis and emerging insights into the diversity of metabolism.

The Diversity of Nutritional Metabolites: Origin, Dissection, and Application in Crop Breeding

The chemical diversity of plants is very high, and plant-based foods provide almost all the nutrients necessary for human health, either directly or indirectly. With advancements in plant metabolomics studies, the concept of nutritional metabolites has been expanded and updated. Because the concentration of many nutrients is usually low in plant-based foods, especially those from crops, metabolome-assisted breeding techniques using molecular markers associated with the synthesis of nutritional metabolites have been developed and used to improve nutritional quality of crops. Here, we review the origins of the diversity of nutrient metabolites from a genomic perspective and the role of gene duplication and divergence. In addition, we systematically review recent advances in the metabolomic and genetic basis of metabolite production in major crops. With the development of genome sequencing and metabolic detection technologies, multi-omic integrative analysis of genomes, transcriptomes, and metabolomes has greatly facilitated the deciphering of the genetic basis of metabolic pathways and the diversity of nutrient metabolites. Finally, we summarize the application of nutrient diversity in crop breeding and discuss the future development of a viable alternative to metabolome-assisted breeding techniques that can be used to improve crop nutrient quality.

Exploring the Diversity of Plant Metabolism

Plants produce a huge array of metabolites, far more than those produced by most other organisms. Unraveling this diversity and its underlying genetic variation has attracted increasing research attention. Post-genomic profiling platforms have enabled the marriage and mining of the enormous amount of phenotypic and genetic diversity. We review here achievements to date and challenges remaining that are associated with plant metabolic research using multi-omic strategies. We focus mainly on strategies adopted in investigating the diversity of plant metabolism and its underlying features. Recent advances in linking metabotypes with phenotypic and genotypic traits are also discussed. Taken together, we conclude that exploring the diversity of metabolism could provide new insights into plant evolution and domestication.

[Clinical characteristics and antimicrobial resistance of pneumococcal infections from 9 children's hospitals in 2016]

Objective: To describe the clinical characteristics of pneumococcal infections and drug resistance of Streptococcus pneumoniae isolates from children's hospitals, which would provide reference for preventing and treating pneumococcal diseases. Methods: This was a prevalence survey. In this study, the age, specimen type, monthly distribution characteristics, and antimicrobial resistance of Streptococcus pneumoniae isolates from 9 children's hospitals in China were investigated between January 1, 2016 and December 31, 2016. The WHONET 5.6 software was used to analyze the antibiotic susceptibility of Streptococcus pneumoniae. The comparison of rates was performed by Chi-square test. Results: A total of 6 200 isolates of streptococcus pneumoniae were obtained, namely, 95.1% (5 876/6 177) from the respiratory tract specimens, 2.2% (136/6 177) from blood specimens and 0.4% (24/6 177) from cerebrospinal fluid specimens. The isolates were mainly from children older than 1 and younger than 5 years (54.7%, 3 381/6 185) . Most of strains (33.2%, 1 184/3 563) were isolated in November, December and January. Streptococcus pneumoniae isolates were completely sensitive to vancomycin (100.0%, 6 189/6 189) , linezolid (100.0%, 6 030/6 030) , moxifloxacin (100.0%, 3 064/3 064) , highly sensitive to levofloxacin (99.8%, 5 528/5 540), ertapenem (98.8%, 3 024/3 061) and lowly sensitive to erythromycin (1.7%, 102/6 016), clindamycin (3.7%, 116/3 136), and tetracycline (5%, 244/4 877), respectively. According to the parenteral susceptibility breakpoints for non-meningitis isolates, the sensitivity of Streptocococus pneumoniae to penicillin from children's hospital of Chongqing Medical University (49.3%, 892/1 809) was significantly lower than those of other hospitals (χ(2)=1 268.161, P<0.05) . Conclusions:Streptococcus pneumoniae is mainly isolated from respiratory tract, from children older than 1 and younger than 5 years and during November to January in tertiary children's hospital of China. The Streptococcus pneumoniae from children is highly sensitive to vancomycin, linezolid, moxifloxacin, levofloxacin. There are also significant differences in the sensitivity of penicillin for Streptococcus pneumoniae from different hospitals.

[Experimental observation on the effect of bone marrow mesenchymal stem cells transplanting CXCR4 over gentamicin ototoxicity]

Objective:To observe the survival and migration ability of CXCR4-BMSCs in guinea pig cochlea with gentamycin induced sensorineural hearing loss, and to explore whether SDF-1/CXCR4 axis can mediate bone marrow mesenchymal stem cells (BMSCs) to cochlear homing.Method:BMSCs were isolated and extracted from guinea pigs. A bone marrow mesenchymal stem cell line with overexpression of CXCR4 was established. The animal model of sensorineural deafness was established by intraperitoneal injection of gentamicin［100 mg/(kg·d)］in 50 healthy guinea pigs. The successful deafness animals were randomly divided into three groups(14 rats in each group): sterilizing water group, BMSCs transplantation group and CXCR4-BMSCs transplantation group.Auditory brainstem response(ABR) were performed at 2 weeks and 4 weeks respectively after the tansplantation through cochlear tympanic pathway. The directional homing of the implanted cells in the cochlea was traced by the frozen section fluorescence of the cochlear tissue.Result:The hearing thresholds of the three groups were (91.3±5.2),(90.7±4.8)and (90.9±5.6)dB (SPL) respectively. There was no significant difference among them(P>0.05). In sterile Water group, the hearing thresholds were(89.7±6.4)dB and (89.2±6.7)dB respectively when detected on 2 and 4 weeks after transplantation. There were no significant difference(P>0.05);In BMSCs group, the hearing thresholds were (88.6±5.3)dB(SPL) on 2 weeks and (78.4±7.3)dB(SPL) on 4 weeks after transplantation. In CXCR4-BMSCs group, the hearing thresholds were(75.3±7.8)dB(SPL) on 2 weeks and (62.1±8.4)dB(SPL) on 4 weeks after transplantation. The differences were statistically significant (PThe hearing threshold was (75.3±7.8)dB (SPL) at 2 weeks after operation. The hearing enhancement was about 15 dB, the hearing threshold was (62.1±8.4)dB(SPL) at 4 weeks, the difference was statistically significant(P<0.05).Fluorescence tracing showed that the number of CXCR4-BMSCs homing cells was significantly increased, and showed a cohort like arrangement.Conclusion:The SDF-1/CXCR4 axis plays an important role in the directional homing and differentiation of the cells into the cochlea, which can improve the hearing repair ability of guinea pigs induced by gentamicin induced sensorineural deafness.

Endocavitary contrast enhanced ultrasound (CEUS): a novel problem solving technique

Abstract

Contrast-enhanced ultrasound (CEUS) is a technique that has developed as an adjunct to conventional ultrasound. CEUS offers a number of benefits over conventional axial imaging with computerised tomography and magnetic resonance imaging, primarily as a “beside” test, without ionising radiation or the safety concerns associated with iodinated/gadolinium-based contrast agents. Intravascular use of ultrasound contrast agents (UCAs) is widespread with extensive evidence for effective use. Despite this, the potential utility of UCAs in physiological and non-physiological cavities has not been fully explored. The possibilities for endocavitary uses of CEUS are described in this review based on a single-centre experience including CEUS technique and utility in confirming drain placement, as well as within the biliary system, urinary system, gastrointestinal tract and intravascular catheters.

Teaching Points

• CEUS offers an excellent safety profile, spatial resolution and is radiation free.

• Endocavitary CEUS provides real-time imaging similar to fluoroscopy in a portable setting.

• Endocavitary CEUS can define internal architecture of physiological cavities.

• Endocavitary CEUS can confirm drain position in physiological and non-physiological cavities.

Magnon Valve Effect between Two Magnetic Insulators

The key physics of the spin valve involves spin-polarized conduction electrons propagating between two magnetic layers such that the device conductance is controlled by the relative magnetization orientation of two magnetic layers. Here, we report the effect of a magnon valve which is made of two ferromagnetic insulators (YIG) separated by a nonmagnetic spacer layer (Au). When a thermal gradient is applied perpendicular to the layers, the inverse spin Hall voltage output detected by a Pt bar placed on top of the magnon valve depends on the relative orientation of the magnetization of two YIG layers, indicating the magnon current induced by the spin Seebeck effect at one layer affects the magnon current in the other layer separated by Au. We interpret the magnon valve effect by the angular momentum conversion and propagation between magnons in two YIG layers and conduction electrons in the Au layer. The temperature dependence of the magnon valve ratio shows approximately a power law, supporting the above magnon-electron spin conversion mechanism. This work opens a new class of valve structures beyond the conventional spin valves.

The Effect of Urine Concentration and pH on the Growth of Escherichia Coli in Canine Urine In Vitro

Background

Lower urinary tract infections are common in dogs, and Escherichia coli is the most common bacterial pathogen isolated. The literature has conflicting evidence regarding the inhibitory effects of urine concentration and pH on E. coli growth.

Hypothesis/Objectives

To determine the effect of different pH and urine concentrations on E. coli growth in vitro.

Animals

Voided urine samples from 10 apparently healthy spayed female dogs were used.

Methods

A matrix of 9 urine specific gravity (USG; 1.010, 1.020, and 1.030) and pH (5.5, 7.0, and 8.5) combinations was prepared by diluting and titrating filtered voided urine samples. Three E. coli isolates were obtained from urine of female dogs with signs of lower urinary tract infection and cultured at different urine pH and USG combinations in wells of a microtiter plate. The number of E. coli colony‐forming units (CFU) per mL of urine was calculated after aerobic incubation of the urine at 37°C for 18 hours, and statistically compared.

Results

Significant differences were identified in the mean log CFU/mL among different combinations of pH and USG. The lowest log CFU/mL were observed in alkaline concentrated urine (pH 8.5 and USG 1.030).

Conclusions and Clinical Importance

Escherichia coli in vitro growth was higher in neutral to acidic and diluted urine compared to alkaline and concentrated urine. The impact of non‐alkalizing diluting diets on the incidence of E. coli lower urinary tract infections should be further explored.

A circular white-light flare with impulsive and gradual white-light kernels

White-light flares are the flares with emissions visible in the optical continuum. They are thought to be rare and pose the most stringent requirements in energy transport and heating in the lower atmosphere. Here we present a nearly circular white-light flare on 10 March 2015 that was well observed by the Optical and Near-infrared Solar Eruption Tracer and Solar Dynamics Observatory. In this flare, there appear simultaneously both impulsive and gradual white-light kernels. The generally accepted thick-target model would be responsible for the impulsive kernels but not sufficient to interpret the gradual kernels. Some other mechanisms including soft X-ray backwarming or downward-propagating Alfvén waves, acting jointly with electron beam bombardment, provide a possible interpretation. However, the origin of this kind of white-light kernel is still an open question that induces more observations and researches in the future to decipher it.

[Application of indocyanine green-fluorescent imaging technique in planning resection line and real-time surgical navigation in small hepatocellular carcinoma]

Objective: To explore the value of near-infrared technology guided by indolecyanine green(ICG) in planning resection line and real-time surgical navigation in small liver cancer. Methods: From March to September 2015, 11 patients with hepatic tumors received hepatectomy were treated in First Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University.There were 5 male and 6 female patients with average age of (55±10)years (range 39-70 years). Among whom, there were 9 cases with hepatocellular carcinoma and 2 cases with colorectal cancer. A near-infrared light camera system was used to detect the liver surfaces before resection, and to plan resection line and surgical specimens. A student's t test was used to compare continuous parametric variables. Results: The ICG-fluorescent imaging and histological examination had been used in the 15 lesions of the 11 patients. Among the 15 lesions, 7 lesions were detected by visual inspections, palpation and ICG-fluorescent imaging, 6 lesions were identified only by ICG-fluorescent imaging, 2 lesions were detected only by ICG-fluorescent imaging after resection.Results of pathologic examination indicated that the total fluorescent type include 5 well differentiated hepatocellular carcinoma and 2 cirrhotic nodule; the partial fluorescent type include 3 moderately differentiated hepatocellular carcinomas and 1 well differentiated hepatocellular carcinomas; the rim fluorescent type included 2 liver metastatic carcinoma and 2 poorly differentiated hepatocellular carcinomas. The average diameter of the tumor size measured by CT was (1.7±0.2)cm, while the average diameter measured by ICG-fluorescent imaging was (1.7±0.3)cm(t=-0.188, P>0.05). Conclusion: Near-infrared technology guided by ICG has important value in planning resection line and real-time surgical navigation in small liver cancer.

The effectiveness of a multidisciplinary hip fracture care model in improving the clinical outcome and the average cost of manpower

After the implementation of the multidisciplinary geriatric hip fracture clinical pathway in 2007, the hospital length of stay and the clinical outcomes improves. Moreover, the cost of manpower for each hip fracture decreases. It proves that this care model is cost-effective.

INTRODUCTION

The objective of this study is to compare the clinical outcomes and the cost of manpower before and after the implementation of the multidisciplinary geriatric hip fracture clinical pathway (GHFCP).

METHODS

The hip fracture data from 2006 was compared with the data of four consecutive years since 2008. The efficiency of the program is assessed using the hospital length of stay. The clinical outcomes include mortality rates and complication rates are compared. Cost of manpower was also analysed.

RESULTS

After the implementation of the GHFCP, the preoperative length of stay shortened significantly from 5.8 days in 2006 to 1.3 days in 2011. The total length of stay in both acute and rehabilitation hospitals were also shortened by 6.1 days and 14.2 days, respectively. The postoperative pneumonia rate also decreased from 1.25 to 0.25%. The short- and long-term mortalities also showed a general improvement. Despite allied health manpower was increased to meet the increased workload, the shortened length of stay accounted for a mark decrease in cost of manpower per hip fracture case.

CONCLUSION

This study proves that the GHFCP shortened the geriatric hip fracture patients' length of stay and improves the clinical outcomes. It is also cost-effective which proves better care is less costly.