Metamagnetic multiband Hall effect in Ising antiferromagnet ErGa2.

Frustrated rare-earth-based intermetallics provide a promising platform for emergent magnetotransport properties through exchange coupling between conduction electrons and localized rare-earth magnetic moments. Metamagnetism, the abrupt change of magnetization under an external magnetic field, is a signature of first-order magnetic phase transitions; recently, metamagnetic transitions in frustrated rare earth intermetallics have attracted interest for their accompanying nontrivial spin structures (e.g., skyrmions) and associated nonlinear and topological Hall effects (THE). Here, we present metamagnetism-induced Hall anomalies in single-crystalline ErGa2, which recalls features arising from the THE but wherein the strong Ising-type anisotropy of Er moments prohibits noncoplanar spin structures. We show that the observed anomalies are neither due to anomalous Hall effect nor THE; instead, can be accounted for via 4f-5d interactions which produce a band-dependent mobility modulation. This leads to a pronounced multiband Hall response across the magnetization process-a metamagnetic multiband Hall effect that resembles a topological-Hall-like response but without nontrivial origins. The present findings may be of general relevance in itinerant metamagnetic systems regardless of coplanar/noncoplanar nature of spins and are important for the accurate identification of Hall signals due to emergent magnetic fields.

Low dosage combination treatment with metformin and simvastatin inhibits obesity-promoted pancreatic cancer development in male KrasG12D mice.

Pancreatic ductal adenocarcinoma (PDAC), a highly lethal disease with limited therapeutic options, may benefit from repurposing of FDA-approved drugs in preventive or interceptive strategies in high-risk populations. Previous animal studies demonstrated that the use of metformin and statins as single agents at relatively high doses restrained PDAC development. Here, four-week-old mice expressing KrasG12D in all pancreatic lineages (KC mice) and fed an obesogenic high fat, high calorie diet that promotes early PDAC development were randomized onto low dosage metformin, simvastatin, or both drugs in combination administered orally. Dual treatment attenuated weight gain, fibro-inflammation, and development of advanced PDAC precursor lesions (pancreatic intraepithelial neoplasia [PanIN]-3) in male KC mice, without significant effect in females or when administered individually. Dual-treated KC mice had reduced proliferation of PanIN cells and decreased transcriptional activity of the Hippo effectors, YAP and TAZ, which are important regulators of PDAC development. Metformin and simvastatin also synergistically inhibited colony formation of pancreatic cancer cells in vitro. Together, our data demonstrated that a combination of low doses of metformin and simvastatin inhibits PDAC development and imply that both drugs are promising agents for being tested in clinical trials for preventing pancreatic cancer progression.

Elastocaloric signatures of symmetric and antisymmetric strain-tuning of quadrupolar and magnetic phases in DyB2C2.

The adiabatic elastocaloric effect measures the temperature change of a given system with strain and provides a thermodynamic probe of the entropic landscape in the temperature-strain space. Here, we demonstrate that the DC bias strain-dependence of AC elastocaloric effect allows decomposition of the latter into symmetric (rotation-symmetry-preserving) and antisymmetric (rotation-symmetry-breaking) strain channels, using a tetragonal [Formula: see text]-electron intermetallic DyB[Formula: see text]C[Formula: see text]-whose antiferroquadrupolar order breaks local fourfold rotational symmetries while globally remaining tetragonal-as a showcase example. We capture the strain evolution of its quadrupolar and magnetic phase transitions using both singularities in the elastocaloric coefficient and its jumps at the transitions, and the latter we show follows a modified Ehrenfest relation. We find that antisymmetric strain couples to the underlying order parameter in a biquadratic (linear-quadratic) manner in the antiferroquadrupolar (canted antiferromagnetic) phase, which are attributed to a preserved (broken) global tetragonal symmetry, respectively. The broken tetragonal symmetry in the magnetic phase is further evidenced by elastocaloric strain-hysteresis and optical birefringence. Additionally, within the staggered quadrupolar order, the observed elastocaloric response reflects a quadratic increase of entropy with antisymmetric strain, analogous to the role magnetic field plays for Ising antiferromagnetic orders by promoting pseudospin flips. Our results demonstrate AC elastocaloric effect as a compact and incisive thermodynamic probe into the coupling between electronic degrees of freedom and strain in free energy, which holds the potential for investigating and understanding the symmetry of a wide variety of ordered phases in broader classes of quantum materials.

Significant increase in mortality and risk of acute ischemic stroke in infective endocarditis patients with subarachnoid hemorrhage secondary to mycotic aneurysms.

Infective Endocarditis (IE) patients are known to have a variety of complications with one of the rarest, but serious being cerebral mycotic aneurysm, which can result in subarachnoid hemorrhage (SAH). Using the National In-Patient Sample database, we sought to determine the rate of acute ischemic stroke (AIS) and outcomes in IE- patients with and without SAH. In total, we identified 82,844 IE-patients from 2010 to 2016, of which 641 had a concurrent diagnosis of SAH. IE patients with SAH had a more complicated course, higher mortality rate (OR 4.65 CI 95% 3.9-5.5, P < 0.001), and worse outcomes. This patient population also had a significantly higher rate of AIS (OR 6.3 CI 95% 5.4-7.4, P < 0.001). Overall, 41.5% of IE-patients with SAH had AIS during their hospitalization as compared to 10.1% of IE only patients. IE-patients with SAH were more likely to undergo endovascular treatment (3.6%) with 0.8% of the IE patients with AIS undergoing mechanical thrombectomy. While IE-patients are at risk for various complications, our study suggests a significant increase in the mortality and risk of AIS in those with SAH.

Spin wavepackets in the Kagome ferromagnet Fe3Sn2: Propagation and precursors.

The propagation of spin waves in magnetically ordered systems has emerged as a potential means to shuttle quantum information over large distances. Conventionally, the arrival time of a spin wavepacket at a distance, d, is assumed to be determined by its group velocity, vg. Here, we report time-resolved optical measurements of wavepacket propagation in the Kagome ferromagnet Fe3Sn2 that demonstrate the arrival of spin information at times significantly less than d/vg. We show that this spin wave "precursor" originates from the interaction of light with the unusual spectrum of magnetostatic modes in Fe3Sn2. Related effects may have far-reaching consequences toward realizing long-range, ultrafast spin wave transport in both ferromagnetic and antiferromagnetic systems.

Statins Inhibit Inflammatory Cytokine Production by Macrophages and Acinar-to-Ductal Metaplasia of Pancreatic Cells.

BACKGROUND AND AIMS: Animal data show that the presence of an oncogenic Kras mutation in pancreatic acinar cells leads to acinar-to-ductal metaplasia (ADM), pancreatic intraepithelial neoplasia (PanIN), and pancreatic ductal adenocarcinoma (PDAC). Inflammatory macrophages play an important role in the formation of ADMs and transition to PanINs. Epidemiologically, statins are associated with a reduced risk of PDAC. We investigated whether statins inhibit inflammatory cytokine production in macrophages and whether this leads to reduced ADM formation. METHODS: The efficacy of statins on inflammatory cytokine production in 2 macrophage cell lines was measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of macrophage-conditioned medium on ADM in primary pancreatic acinar cells was investigated. Mouse pancreatic tissue samples were analyzed for macrophage numbers, cytokine levels, and neoplastic/dysplastic area. RESULTS: Lipophilic statins prevented inflammatory cytokine production in Raw264.7 and J774A.1 cells stimulated by lipopolysaccharide. The inhibitory effect of statins was mediated by inhibition of mevalonate and geranylgeranyl pyrophosphate synthesis and disruption of the actin cytoskeleton but not by a reduction in intracellular cholesterol. Treatment of macrophages with lipophilic statins also blocked ADM formation of primary pancreatic acinar cells. Furthermore, oral administration of simvastatin was associated with a reduction in the number of intrapancreatic macrophages, decreased inflammatory cytokine levels in the pancreas, and attenuated ADM/PanIN formation in mice. CONCLUSION: Our data support the hypothesis that statins oppose early PDAC development by their effects on macrophages and ADM formation. The inhibitory actions of statins on macrophages may collaborate with direct inhibitory effects on transformed pancreatic epithelial cells, which cumulatively may reduce early PDAC development and progression.

Snapshots of a light-induced metastable hidden phase driven by the collapse of charge order.

Nonequilibrium hidden states provide a unique window into thermally inaccessible regimes of strong coupling between microscopic degrees of freedom in quantum materials. Understanding the origin of these states allows the exploration of far-from-equilibrium thermodynamics and the development of optoelectronic devices with on-demand photoresponses. However, mapping the ultrafast formation of a long-lived hidden phase remains a longstanding challenge since the initial state is not recovered rapidly. Here, using state-of-the-art single-shot spectroscopy techniques, we present a direct ultrafast visualization of the photoinduced phase transition to both transient and long-lived hidden states in an electronic crystal, 1T-TaS2, and demonstrate a commonality in their microscopic pathways, driven by the collapse of charge order. We present a theory of fluctuation-dominated process that helps explain the nature of the metastable state. Our results shed light on the origin of this elusive state and pave the way for the discovery of other exotic phases of matter.

Higher risk tumor features are not associated with higher nodal stage in patients with estrogen receptor-positive, node-positive breast cancer.

INTRODUCTION: Studies support omission of axillary lymph node dissection (ALND) for patients with sentinel node-positive disease, with ALND recommended for patients who present with clinically positive nodes. Here, we evaluate patient and tumor characteristics and pathologic nodal stage of patients with estrogen receptor-positive (ER +) breast cancer who undergo ALND to determine if differences exist based on nodal presentation. MATERIALS AND METHODS: Retrospective chart review from 2010 to 2019 defined three groups of patients with ER + breast cancer who underwent ALND for positive nodes: SLN + (positive node identified at SLN biopsy), cNUS (abnormal preoperative US and biopsy), and cNpalp (palpable adenopathy). Patients who received neoadjuvant chemotherapy or presented with axillary recurrence were excluded. RESULTS: Of 191 patients, 94 were SLN + , 40 were cNUS, and 57 were cNpalp. Patients with SLN + compared with cNpalp were younger (56 vs 64 years, p < 0.01), more often pre-menopausal (41% vs 14%, p < 0.01), and White (65% vs 39%, p = 0.01) with more tumors that were low-grade (36% vs 8%, p < 0.01). Rates of PR + (p = 0.16), levels of Ki67 expression (p = 0.07) and LVI (p = 0.06) did not differ significantly among groups. Of patients with SLN + disease, 64% had pN1 disease compared to 38% of cNUS (p = 0.1) and 40% of cNpalp (p = 0.01). On univariable analysis, tumor size (p = 0.01) and histology (p = 0.04) were significantly associated with pN1 disease, with size remaining an independent predictor on multivariable analysis (p = 0.02). CONCLUSION: Historically, higher risk features have been attributed to patients with clinically positive nodes precluding omission of ALND, but when restricting evaluation to patients with ER + breast cancer, only tumor size is associated with higher nodal stage.

Hospitalizations in solid tumor phase I clinical trial patients: Incidence, pattern and clinical outcomes at an Australian phase I clinical trial unit.

BACKGROUND: Participation in early-phase clinical trials has become a prominent part of medical oncology patient management. We examined the incidence and pattern of hospitalizations in early-phase clinical trial patients and the associated clinical outcomes. METHOD: We conducted a retrospective review of 194 patients with solid tumors treated on phase I clinical trials between July 2014 and October 2018 at a phase I trial unit. Unplanned hospitalizations occurring during the study period were characterized and correlated with treatment response and duration of trial participation. RESULTS: Among 194 patients, 104 hospitalizations were recorded involving 62 patients (31%). Nineteen percent of patients were hospitalized for cancer-related complications and 8% for treatment toxicity. No significant correlation was seen between the hospitalization and age, sex, tumor type, or trial drug. Best response to trial therapy was complete response, partial response, stable disease, and progressive disease in 5%, 11%, 37%, and 47% of patients, respectively. Median duration on trial was 86 days (range 0-1,412). Twenty-two patients (11%) remained on trial for more than 12 months. Overall, hospitalization did not impact treatment response or trial duration. However, cancer-related hospitalization was associated with significantly lower response (p < 0.001) and early patient attrition (p < 0.001). Resolution of the hospitalization event was associated with improved response (p = 0.002) and longer duration on trial (p < 0.001). The treatment related mortality was 0.5% (n = 1). CONCLUSION: Approximately one third of patients required hospitalization, most commonly for cancer-related complications which correlated with poorer clinical outcomes. Hospitalizations related to treatment toxicity were infrequent. A significant proportion of patients derived significant therapeutic benefit. Phase I clinical trials provide a valuable treatment option for patients with cancer.

Clinical outcomes and cost of robotic ventral hernia repair: systematic review.

BACKGROUND: Robotic ventral hernia repair (VHR) has seen rapid adoption, but with limited data assessing clinical outcome or cost. This systematic review compared robotic VHR with laparoscopic and open approaches. METHODS: This systematic review was undertaken in accordance with PRISMA guidelines. PubMed, MEDLINE, Embase, and Cochrane databases were searched for articles with terms relating to 'robot-assisted', 'cost effectiveness', and 'ventral hernia' or 'incisional hernia' from 1 January 2010 to 10 November 2020. Intraoperative and postoperative outcomes, pain, recurrence, and cost data were extracted for narrative analysis. RESULTS: Of 25 studies that met the inclusion criteria, three were RCTs and 22 observational studies. Robotic VHR was associated with a longer duration of operation than open and laparoscopic repairs, but with fewer transfusions, shorter hospital stay, and lower complication rates than open repair. Robotic VHR was more expensive than laparoscopic repair, but not significantly different from open surgery in terms of cost. There were no significant differences in rates of intraoperative complication, conversion to open surgery, surgical-site infection, readmission, mortality, pain, or recurrence between the three approaches. CONCLUSION: Robotic VHR was associated with a longer duration of operation, fewer transfusions, a shorter hospital stay, and fewer complications compared with open surgery. Robotic VHR had higher costs and a longer operating time than laparoscopic repair. Randomized or matched data with standardized reporting, long-term outcomes, and cost-effectiveness analyses are still required to weigh the clinical benefits against the cost of robotic VHR.

Comparison of Clinical Outcomes of Robot-Assisted, Video-Assisted, and Open Esophagectomy for Esophageal Cancer: A Systematic Review and Meta-analysis.

Importance: The utilization of robot-assisted minimally invasive esophagectomy (RAMIE) for esophageal cancer is increasing, despite limited data comparing RAMIE with other surgical approaches. Objective: To evaluate the literature for clinical outcomes of RAMIE compared with video-assisted minimally invasive esophagectomy (VAMIE) and open esophagectomy (OE). Data Sources: A systematic search of PubMed, Cochrane, Ovid Medline, and Embase databases from January 1, 2013, to May 6, 2020, was performed. Study Selection: Studies that compared RAMIE with VAMIE and/or OE for cancer were included. Data Extraction and Synthesis: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline, data were extracted by independent reviewers. A random-effects meta-analysis of 9 propensity-matched studies was performed for the RAMIE vs VAMIE comparison only. A narrative synthesis of RAMIE vs VAMIE and OE was performed. Main Outcomes and Measures: The outcomes of interest were intraoperative outcomes (ie, estimated blood loss [EBL], operative time, lymph node [LN] harvest), short-term outcomes (anastomotic leak, recurrent laryngeal nerve [RLN] palsy, pulmonary and total complications, and 90-day mortality), and long-term oncologic outcomes. Results: Overall, 21 studies (2 randomized clinical trials, 11 propensity-matched studies, and 8 unmatched studies) with 9355 patients were included. A meta-analysis was performed with 9 propensity-matched studies comparing RAMIE with VAMIE. The random-effects pooled estimate found an adjusted risk difference (RD) of -0.06 (95% CI, -0.11 to -0.01) favoring fewer pulmonary complications with RAMIE. There was no evidence of differences between RAMIE and VAMIE in LN harvest (mean difference [MD], -1.1 LN; 95% CI, -2.45 to 0.25 LNs), anastomotic leak (RD, 0.0; 95% CI, -0.03 to 0.03), EBL (MD, -6.25 mL; 95% CI, -18.26 to 5.77 mL), RLN palsy (RD, 0.01; 95% CI, -0.08 to 0.10), total complications (RD, 0.05; 95% CI, -0.01 to 0.11), or 90-day mortality (RD, -0.01; 95% CI, -0.02 to 0.0). There was low certainty of evidence that RAMIE was associated with a longer disease-free survival compared with VAMIE. For OE comparisons (data not pooled), RAMIE was associated with a longer operative time, decreased EBL, and less pulmonary and total complications. Conclusions and Relevance: In this study, RAMIE had similar outcomes as VAMIE but was associated with fewer pulmonary complications compared with VAMIE and OE. Studies on long-term functional and cancer outcomes are needed.

Evidence of two-dimensional flat band at the surface of antiferromagnetic kagome metal FeSn.

The kagome lattice has long been regarded as a theoretical framework that connects lattice geometry to unusual singularities in electronic structure. Transition metal kagome compounds have been recently identified as a promising material platform to investigate the long-sought electronic flat band. Here we report the signature of a two-dimensional flat band at the surface of antiferromagnetic kagome metal FeSn by means of planar tunneling spectroscopy. Employing a Schottky heterointerface of FeSn and an n-type semiconductor Nb-doped SrTiO3, we observe an anomalous enhancement in tunneling conductance within a finite energy range of FeSn. Our first-principles calculations show this is consistent with a spin-polarized flat band localized at the ferromagnetic kagome layer at the Schottky interface. The spectroscopic capability to characterize the electronic structure of a kagome compound at a thin film heterointerface will provide a unique opportunity to probe flat band induced phenomena in an energy-resolved fashion with simultaneous electrical tuning of its properties. Furthermore, the exotic surface state discussed herein is expected to manifest as peculiar spin-orbit torque signals in heterostructure-based spintronic devices.

The Effect of Perioperative Blood Transfusion on Long-Term Survival Outcomes After Surgery for Pancreatic Ductal Adenocarcinoma: A Systematic Review.

OBJECTIVE: To evaluate survival outcomes associated with perioperative allogeneic red blood cell transfusion (RBCT) in patients with pancreatic ductal adenocarcinoma undergoing surgery. METHODS: PubMed, Embase, Cochrane, and Web of Science Core Collection were queried for English-language articles until May 28, 2020. Studies evaluating long-term outcomes of RBCT compared with no transfusion in adults with pancreatic ductal adenocarcinoma undergoing pancreatectomy were included. E-value sensitivity analysis assessed the potential for unmeasured confounders to overcome these findings. RESULTS: Of 4379 citations, 5 retrospective cohort studies were included. Three studies reported shorter recurrence-free survival by 1 to 5 months with RBCT. Two studies found shorter disease-specific survival by 5 to 13 months with RBCT. Overall survival was reduced by 5 to 7 months with RBCT in 3 studies. All multivariable findings associated with RBCT could be readily overcome unmeasured confounding on sensitivity analysis. Confounding in baseline characteristics resulted in high risk of bias. CONCLUSIONS: Imprecision, unmeasured confounding, small effect sizes, and overall low quality of the available literature result in uncertainty regarding the effect of transfusion on recurrence-free survival, disease-specific survival, and overall survival in patients undergoing surgery for pancreatic cancer. Randomized trials are needed to determine if there is a causal relationship between transfusion and survival after pancreatic resection.

Direct Effects of Lipopolysaccharide on Human Pancreatic Cancer Cells.

OBJECTIVES: Obesity, a risk factor for pancreatic adenocarcinoma (PDAC), is often accompanied by a systemic increase in lipopolysaccharide (LPS; metabolic endotoxemia), which is thought to mediate obesity-associated inflammation. However, the direct effects of LPS on PDAC cells are poorly understood. METHODS: The expression of toll-like receptor 4, the receptor for LPS, was confirmed in PDAC cell lines. AsPC-1 and PANC-1 cells were exposed to LPS, and differential gene expression was determined by RNA sequencing. The activation of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway by LPS in PDAC cells was assessed by Western blotting. RESULTS: The expression of toll-like receptor 4 was confirmed in all PDAC cell lines. The exposure to LPS led to differential expression of 3083 genes (426 ≥5-fold) in AsPC-1 and 2584 genes (339 ≥5-fold) in PANC-1. A top canonical pathway affected by LPS in both cell lines was PI3K/Akt/mTOR. Western blotting confirmed activation of this pathway as measured by phosphorylation of the ribosomal protein S6 and Akt. CONCLUSIONS: The exposure of PDAC cells to LPS led to differential gene expression. A top canonical pathway was PI3K/Akt/mTOR, a known oncogenic driver. Our findings provided evidence that LPS can directly induce differential gene expression in PDAC cells.

Intraoperative and postoperative outcomes of robot-assisted cholecystectomy: a systematic review.

BACKGROUND: Rapid adoption of robotic-assisted general surgery procedures, particularly for cholecystectomy, continues while questions remain about its benefits and utility. The objective of this study was to compare the clinical effectiveness of robot-assisted cholecystectomy for benign gallbladder disease as compared with the laparoscopic approach. METHODS: A literature search was performed from January 2010 to March 2020, and a narrative analysis was performed as studies were heterogeneous. RESULTS: Of 887 articles screened, 44 met the inclusion criteria (range 20-735,537 patients). Four were randomized controlled trials, and four used propensity-matching. There were variable comparisons between operative techniques with only 19 out of 44 studies comparing techniques using the same number of ports. Operating room time was longer for the robot-assisted technique in the majority of studies (range 11-55 min for 22 studies, p < 0.05; 15 studies showed no difference; two studies showed shorter laparoscopic times), while conversion rates and intraoperative complications were not different. No differences were detected for the length of stay, surgical site infection, or readmissions. Across studies comparing single-port robot-assisted to multi-port laparoscopic cholecystectomy, there was a higher rate of incisional hernia; however, no differences were noted when comparing single-port robot-assisted to single-port laparoscopic cholecystectomy. CONCLUSIONS: Clinical outcomes were similar for benign, elective gallbladder disease for robot-assisted compared with laparoscopic cholecystectomy. Overall, the rates of complications were low. More high-quality studies are needed as the robot-assisted technique expands to more complex gallbladder disease, where its utility may prove increasingly beneficial. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020156945.

The Current Lung Cancer Neoantigen Landscape and Implications for Therapy.

All tumors harbor unique mutant peptides, some of which are able to elicit T-cell-mediated immune responses. These are known as neoantigens. Lung cancers bear a heavy mutational burden and hence many potential neoantigens. Neoantigens are increasingly recognized as key mediators of tumor-specific immune activation and have been identified as potential targets for personalized cancer therapies. In this review, we discuss the current data on neoantigens in lung cancer and provide an overview of the recent advances in neoantigen-based immunotherapy. Furthermore, we look ahead to highlight the major opportunities and challenges for the clinical application of neoantigen-based treatment strategies for thoracic and other malignancies.

Narrative review of immunotherapy and radiation therapy in elderly patients.

Cancer is primarily a disease of the elderly, but there is a disproportionate lack of data from clinical trials in this population. Oncologists tend to underdiagnose and undertreat geriatric patients with cancer, leading to poor survival outcomes. New therapies or therapeutic combinations such as immunotherapy and stereotactic body radiation therapy (SBRT) can be used in the elderly for better tumor control and survival, with fewer toxicities. The aim of this review is to describe the synergistic effects of immunotherapy and radiation therapy (RT) and to discuss the use of these therapies concurrently and/or sequentially in the elderly. To gain a fuller picture of their elderly patient's health, physicians may also consider incorporating a comprehensive geriatric assessment (CGA) to evaluate their functional capacity, cognition, physical and mental health, and social supports which we will discuss in this review. It is recommended that oncologists use geriatric assessments in their everyday practice to have better insight on their complex elderly patients, therefore providing them a higher quality of care. They should also be incorporated in clinical trials as a way to assess and include more elderly patients in the study. Ultimately, the elderly deserve to be treated with more than their chronological age in mind, and new combination therapies and use of a geriatric assessment can help achieve that.