Highly reversible extrinsic electrocaloric effects over a wide temperature range in epitaxially strained SrTiO3 films

Electrocaloric effects have been experimentally studied in ferroelectrics and incipient ferroelectrics, but not incipient ferroelectrics driven ferroelectric using strain. Here we use optimally oriented interdigitated surface electrodes to investigate extrinsic electrocaloric effects in low-loss epitaxial SrTiO3 films near the broad second-order 243 K ferroelectric phase transition created by biaxial in-plane coherent tensile strain from DyScO3 substrates. Our extrinsic electrocaloric effects are an order of magnitude larger than the corresponding effects in bulk SrTiO3 over a wide range of temperatures including room temperature, and unlike electrocaloric effects associated with first-order transitions they are highly reversible in unipolar applied fields. Additionally, the canonical Landau description for strained SrTiO3 films works well if we set the low-temperature zero-field polarization along one of the in-plane pseudocubic <100> directions. In future, similar strain engineering could be exploited for other films, multilayers and bulk samples to increase the range of electrocaloric materials for energy efficient cooling.

Isolating the Role of Bone Lacunar Morphology on Static and Fatigue Fracture Progression through Numerical Simulations

Currently, the onset of bone damage and the interaction of cracks with the surrounding micro-architecture are still black boxes. With the motivation to address this issue, our research targets isolating lacunar morphological and densitometric effects on crack advancement under both static and cyclic loading conditions by implementing static extended finite element models (XFEM) and fatigue analyses. The effect of lacunar pathological alterations on damage initiation and progression is evaluated; the results indicate that high lacunar density considerably reduces the mechanical strength of the specimens, resulting as the most influencing parameter among the studied ones. Lacunar size has a lower effect on mechanical strength, reducing it by 2%. Additionally, specific lacunar alignments play a key role in deviating the crack path, eventually slowing its progression. This could shed some light on evaluating the effects of lacunar alterations on fracture evolution in the presence of pathologies.

Guideline Application in Real world: multi-Institutional Based survey of Adjuvant and first-Line pancreatic Ductal adenocarcinoma treatment in Italy. Primary analysis of the GARIBALDI survey

BACKGROUND

Information about the adherence to scientific societies guidelines in the 'real-world' therapeutic management of oncological patients are lacking. This multicenter, prospective survey was aimed to improve the knowledge relative to 2017-2018 recommendations of the Italian Association of Medical Oncology (AIOM).

PATIENTS AND METHODS

Treatment-naive adult patients with pancreatic adenocarcinoma were enrolled. Group A received adjuvant therapy, group B received primary chemotherapy, and group C had metastatic disease. The results on patients accrued until 31 October 2019 with a mature follow-up were presented.

RESULTS

Since July 2017, 833 eligible patients of 923 (90%) were enrolled in 44 Italian centers. The median age was 69 years (range 36-89 years; 24% >75 years); 48% were female; 93% had Eastern Cooperative Oncology Group (ECOG) performance status (PS) score of 0 or 1; group A: 16%, group B: 30%; group C: 54%; 72% Nord, 13% Center, 15% South. In group A, guidelines adherence was 68% [95% confidence interval (CI) 59% to 76%]; 53% of patients received gemcitabine and 15% gemcitabine + capecitabine; median CA19.9 was 29 (range 0-7300; not reported 15%); median survival was 36.4 months (95% CI 27.5-47.3 months). In group B, guidelines adherence was 96% (95% CI 92% to 98%); 55% of patients received nab-paclitaxel + gemcitabine, 27% FOLFIRINOX, 12% gemcitabine, and 3% clinical trial; median CA19.9 was 337 (range 0-20220; not reported 9%); median survival was 18.1 months (95% CI 15.6-19.9 months). In group C, guidelines adherence was 96% (95% CI 94% to 98%); 71% of patients received nab-paclitaxel + gemcitabine, 16% gemcitabine, 8% FOLFIRINOX, and 4% clinical trial; liver and lung metastases were reported in 76% and 23% of patients, respectively; median CA19.9 value was 760 (range 0-1374500; not reported 9%); median survival was 10.0 months (95% CI 9.1-11.1 months).

CONCLUSIONS

The GARIBALDI survey shows a very high rate of adherence to guidelines and survival outcome in line with the literature. CA19.9 testing should be enhanced; nutritional and psychological counseling represent an unmet need. Enrollment to assess adherence to updated AIOM guidelines is ongoing.

Characterization of the HER2 status in BRCA-mutated breast cancer: a single institutional series and systematic review with pooled analysis

BACKGROUND

Pathogenic variants (PVs) in BRCA1/2 genes account for ∼6% of breast and 20% of ovarian cancers. Most breast tumors developed by BRCA1 carriers are triple negative. BRCA2 tumors have similar rates of estrogen receptor positivity as sporadic controls but are less likely to be human epidermal growth factor receptor 2 (HER2)-positive. Prevalence of HER2 positivity among breast cancers (BCs) in BRCA1/2 mutation carriers is poorly and variably described, ranging from 0% to 10% and 0% to 13% in BRCA1 and BRCA2 carriers, respectively.

PATIENTS AND METHODS

We assessed the prevalence of HER2 positivity among a single institutional cohort of 398 BCs developed in carriers of BRCA1/2 PVs (240 BRCA1, 158 BRCA2). Subsequently, a systematic review of the literature and pooled analysis was carried out.

RESULTS

In our series we found a 7% HER2 positivity rate among all first BRCA1/2 BCs overall. In BRCA1 carriers, 5.4% of BCs were HER2-positive compared with 9.5% in BRCA2-mutated patients. Among bilateral BCs, HER2-positive cases were 15.2% in the BRCA1 group and 23.1% in the BRCA2 group. Notably, six BRCA1 and eight BRCA2 carriers showed discordant HER2 status between BC and bilateral BC (23.7%, 14/59). The systematic review included 21 083 BRCA1/2 patients from 73 eligible studies. The pooled rate of BRCAmut/HER2-positive BCs is 9.1% (95% confidence interval 7.3% to 11.2%). BRCA1 and BRCA2 when reported as separate data ranged from 0% to 33.3% (mean 8.3%) and from 0% to 86% (mean 10.3%), respectively.

CONCLUSIONS

As compared with sporadic cases, BCs occurring in BRCA1 and/or BRCA2 PVs carriers are less frequently HER2-positive. Prevalence of HER2 positivity in our series was consistent with pooled analysis and did not exceed 10%. Although not common, co-existence of BRCA mutations and HER2 overexpression and/or gene amplification should be acknowledged. More research is needed to better characterize this subgroup of patients who should not be excluded a priori from clinical trials of targeted therapy for BRCA1/2-driven cancers.

Exchange-bias via nanosegregation in novel Fe2-x Mn1+x Al (x = -0.25, 0, 0.25) Heusler films

Exchange-bias has been reported in bulk nanocrystalline Fe₂MnAl, but individual thin films of this Heusler alloy have never been studied so far. Here we study the structural and magnetic properties of nanocrystalline thin films of Fe_2-x Mn_1+x Al (x = -0.25, 0 and 0.25) obtained by sputtering and ex situ post-deposition annealing. We find that Fe₂MnAl films display exchange-bias, and that varying Mn concentration determines the magnitude of the effect, which can be either enhanced (in Fe_1.75Mn_1.25Al) or suppressed (in Fe_2.25Mn_0.75Al). X-ray diffraction shows that our films present a mixed L2₁-B2 Heusler structure where increasing Mn concentration favors the partial transformation of the L2₁ phase into the B2 phase. Scanning transmission electron microscopy (STEM) and energy dispersive X-ray spectroscopy (EDX) reveal that this composition-driven L2₁ → B2 transformation is accompanied by phase segregation at the nanoscale. As a result, the Fe_2-x Mn_1+x Al films that show exchange-bias (x = 0, 0.25) are heterogeneous, with nanograins of an Fe-rich phase embedded in a Mn-rich matrix (a non-negative matrix factorisation algorithm was used to give an indication of the phase composition from EDX data). Our comparative analysis of XRD, magnetometry and X-ray magnetic circular dichroism (XMCD), shows that the Fe-rich nanograins and Mn-rich matrix are composed of a ferromagnetic L2₁ phase and an antiferromagnetic B2 phase, respectively, thus revealing that exchange-coupling between these two phases is the cause of the exchange-bias effect. Our work should inspire the development of single-layer, environmentally friendly spin valve devices based on nanocomposite Heusler films.

Voltage-driven annihilation and creation of magnetic vortices in Ni discs

Using photoemission electron microscopy (PEEM) to image ferromagnetism in polycrystalline Ni disks, and ferroelectricity in their single-crystal BaTiO₃ substrates, we find that voltage-driven 90° ferroelectric domain switching serves to reversibly annihilate each magnetic vortex via uniaxial compressive strain, and that the orientation of the resulting bi-domain reveals the chirality of the annihilated vortex. Micromagnetic simulations reveal that only 60% of this strain is required for annihilation. Voltage control of magnetic vortices is novel, and should be energetically favourable with respect to the use of a magnetic field or an electrical current. In future, stray field from bi-domains could be exploited to read vortex chirality. Given that core polarity can already be read via stray field, our work represents a step towards four-state low-power memory applications.

Shear-strain-mediated magnetoelectric effects revealed by imaging

Large changes in the magnetization of ferromagnetic films can be electrically driven by non-180° ferroelectric domain switching in underlying substrates, but the shear components of the strains that mediate these magnetoelectric effects have not been considered so far. Here we reveal the presence of these shear strains in a polycrystalline film of Ni on a 0.68Pb(Mg_1/3Nb_2/3)O₃-0.32PbTiO₃ substrate in the pseudo-cubic (011)_pc orientation. Although vibrating sample magnetometry records giant magnetoelectric effects that are consistent with the hitherto expected 90° rotations of a global magnetic easy axis, high-resolution vector maps of magnetization (constructed from photoemission electron microscopy data, with contrast from X-ray magnetic circular dichroism) reveal that the local magnetization typically rotates through smaller angles of 62-84°. This shortfall with respect to 90° is a consequence of the shear strain associated with ferroelectric domain switching. The non-orthogonality represents both a challenge and an opportunity for the development and miniaturization of magnetoelectric devices.

Epidemiological, clinical and pathological characteristics of gastric neoplasms in the province of Cremona: the experience of the first population-based specialized gastric cancer registry in Italy

BACKGROUND

The gastric cancer incidence rate differs widely across geographical areas. In Italy, in the province of Cremona the incidence is high, compared to the national situation. For this reason a specialized population-based registry was set up.

METHODS

The collection encompasses all gastric cancers diagnosed in the three districts of the province since January 1, 2010. The main data sources were the pathological and Hospital Discharge Records and patient clinical charts. Only diagnoses of primary gastric cancer were considered. For each case the following variables were registered: personal data, medical history and symptoms at diagnosis; imaging assessments performed, details on surgery and other treatments received; genetic background and biomolecular characteristics; social and environmental factors.

RESULTS

As of November 2017, 1087 cases were collected; of which 876, diagnosed up to December 2015, were analyzed. Male/female ratio was 1.4. The European Age-standardized Incidence Rate was 41.4 for males and 28.3 for females as compared to a national average of 33.3 and 17.0 respectively. Median age at diagnosis was 73 for male and 78 for female. Helicobacter Pylori infection was present in fewer than 20% of cases. HER-2 gene was amplified in about 25% of cases. Primary tumour location was the gastro-esophageal junction or cardia in 17.5% in males and 8.3% in females. The majority of cases (58.3%) were diagnosed at an advanced stage and overall only 41.2% underwent surgery. Median overall survival was 14.8 months for men and 18.5 for women. Age standardized 5-year relative survival was 31.4% for men and 40.5% for females. Neoadjuvant treatment was performed in fewer than 10% of patients who underwent surgery, and the rate of postoperative therapy adherence was low.

DISCUSSION

This study shows a high gastric cancer incidence in the province of Cremona, with a geographical spread across different districts. Moreover, a high percentage of gastric cancers were detected at an advanced stage of disease and a low rate of 5-year relative survival was registered. Based on these findings, effective preventive interventional health strategies and screening procedures need to be implemented to reduce the impact of this pathology in this geographical area.

Estimating 12-week death probability in patients with refractory metastatic colorectal cancer: the Colon Life nomogram

Background

Regorafenib and TAS-102 have recently demonstrated statistically significant survival gains in patients with refractory metastatic colorectal cancer (mCRC). Life expectancy ≥12 weeks was an inclusion criterion in registrative trials, and the identification of proper clinical selection tools for the daily use of these drugs in heavily pre-treated patients is needed to improve the cost-benefit ratio. We aimed at building a nomogram able to predict death probability within 12 weeks from the date of assessment of refractory mCRC.

Patients and methods

Four hundred eleven refractory mCRC patients with ECOG performance status (PS) ≤2 receiving regorafenib, TAS-102 or other treatments were used as developing set. Putative prognostic variables were selected using a random forest model and included in a binary logistic model from which the nomogram was developed. The nomogram was externally validated and its performance was evaluated by examining calibration (how close predictions were to the actual outcome) and discriminative ability (Harrell C index) both on developing (internal validation) and validating (external validation) sets.

Results

Four variables were selected and included in the nomogram: PS (P < 0.0001), primary tumor resection (P = 0.027), LDH value (P = 0.0001) and peritoneal involvement (P = 0.081). In the developing set, the nomogram discriminative ability was high (C = 0.778), and was confirmed in the validating set (C = 0.778), where the overall outcome was better as a consequence of the enrichment in patients receiving regorafenib or TAS-102 (46% versus 34%; P < 0.0001).

Conclusions

Our nomogram may be a useful tool to predict the probability of death within 12 weeks in patients with refractory mCRC. Based on four easy-to-collect variables, the 'Colon Life' nomogram and free app for smartphones may improve mCRC patients' selection for later-line therapies and assist researchers for the enrollment in clinical trials in this setting.

Long Spin Diffusion Length in Few-Layer Graphene Flakes

We report a spin valve with a few-layer graphene flake bridging highly spin-polarized La_{0.67}Sr_{0.33}MnO_{3} electrodes, whose surfaces are kept clean during lithographic definition. Sharp magnetic switching is verified using photoemission electron microscopy with x-ray magnetic circular dichroism contrast. A naturally occurring high interfacial resistance ∼12  MΩ facilitates spin injection, and a large resistive switching (0.8  MΩ at 10 K) implies a 70-130  μm spin diffusion length that exceeds previous values obtained with sharp-switching electrodes.

Magnetoelectric CoFe2O4/polyvinylidene fluoride electrospun nanofibres

Magnetoelectric 0-1 composites comprising CoFe2O4 (CFO) nanoparticles in a polyvinylidene fluoride (PVDF) polymer-fibre matrix have been prepared by electrospinning. The average diameter of the electrospun composite fibres is ∼325 nm, independent of the nanoparticle content, and the amount of the crystalline polar β phase is strongly enhanced when compared to pure PVDF polymer fibres. The piezoelectric response of these electroactive nanofibres is modified by an applied magnetic field, thus evidencing the magnetoelectric character of the CFO/PVDF 0-1 composites.

Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain

Large thermal changes driven by a magnetic field have been proposed for environmentally friendly energy-efficient refrigeration, but only a few materials that suffer hysteresis show these giant magnetocaloric effects. Here we create giant and reversible extrinsic magnetocaloric effects in epitaxial films of the ferromagnetic manganite La(0.7)Ca(0.3)MnO(3) using strain-mediated feedback from BaTiO(3) substrates near a first-order structural phase transition. Our findings should inspire the discovery of giant magnetocaloric effects in a wide range of magnetic materials, and the parallel development of nanostructured bulk samples for practical applications.

A randomized phase II trial of two different four-drug combinations in advanced pancreatic adenocarcinoma: Cisplatin, capecitabine, gemcitabine plus either epirubicin or docetaxel

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Background: The combination of cisplatin (P), epirubicin (E), 5-fluorouracil (F) and gemcitabine (G) (PEFG regimen) yielded a progression-free survival at 6 months from treatment start (PFS6) of about 50% and a 1-year overall survival (OS) around 40% in patients with advanced pancreatic adenocarcinoma (PA). The current trial was aimed to assess whether the replacement of E with docetaxel (D) may improve PFS6. Methods: Chemo-naive patients with stage III or metastatic PA, age 18–75y, Karnofsky performance status (PS) >50 received P (30 mg/m2 day 1), G (800 mg/m2 day 1) and capecitabine (1250 mg/m2/day days 1 to 14) and were randomized to receive either D at 25–30 mg/m2 day 1 (arm A: PDXG regimen) or E at 30 mg/m2 day 1 (arm B: PEXG regimen). Cycles were repeated every 14 days for a maximum of 6 months. Tumor was assessed by CT scan every 8 weeks. The Fleming design was used to calculate the sample size on the probability of being PFS6 (primary endpoint). Assuming P0=40% and P1=60%, α .05 and β.10, the study was to enroll 52 patients per arm. The regimen had to be considered of interest with > 26 patients being PFS6. Results: Between July 2005 and September 2008, 105 patients were enrolled at a single institution, stratified by stage and randomized (53 arm A). Patients’ characteristics were (A/B): median age 61/59, PS > 70 92/88%, metastatic disease 66/65%; CA19.9 > upper limit of laboratory normal (ULN) 87/90%, median CA19.9 820/755 UI/mL. To date, 46 patients per arm are assessable for the primary endpoint: PFS6 was 58/54%. One- year OS was 41% in both arms. A partial response was observed in 61/37% of patients. Among assessable patients with basal CA19.9 value > ULN (37 per arm), a major biochemical response (reduction >89%) was observed in 46/35% and a minor biochemical response (reduction between 50 and 89%) in 43/35% of patients. Main per cycle G3–4 toxicity was: neutropenia 4/13%, thrombocytopenia 3/2%, anemia 4/3%, fatigue 6/4%. Conclusions: PEXG yielded similar results when compared to prior series treated by PEFG, suggesting that capecitabine may replace F. The inclusion of D instead of E seems to be promising. The present trial confirms the relevant impact on outcome of advanced PA of four-drug regimens.

No significant financial relationships to disclose.