Bimodal grain-size scaling of thermal transport in polycrystalline graphene from large-scale molecular dynamics simulations

Grain boundaries in graphene are inherent in wafer-scale samples prepared by chemical vapor deposition. They can strongly influence the mechanical properties and electronic and heat transport in graphene. In this work, we employ extensive molecular dynamics simulations to study thermal transport in large suspended polycrystalline graphene samples. Samples of different controlled grain sizes are prepared by a recently developed efficient multiscale approach based on the phase field crystal model. In contrast to previous works, our results show that the scaling of the thermal conductivity with the grain size implies bimodal behaviour with two effective Kapitza lengths. The scaling is dominated by the out-of-plane (flexural) phonons with a Kapitza length that is an order of magnitude larger than that of the in-plane phonons. We also show that in order to get quantitative agreement with the most recent experiments, quantum corrections need to be applied to both the Kapitza conductance of grain boundaries and the thermal conductivity of pristine graphene and the corresponding Kapitza lengths must be renormalized accordingly.Comment: Accepted to Nano Lett.; Numerical samples and computer codes availabl

Bimodal grain-size scaling of thermal transport in polycrystalline graphene from large-scale molecular dynamics simulations

Grain boundaries in graphene are inherent in wafer-scale samples prepared by chemical vapor deposition. They can strongly influence the mechanical properties and electronic and heat transport in graphene. In this work, we employ extensive molecular dynamics simulations to study thermal transport in large suspended polycrystalline graphene samples. Samples of different controlled grain sizes are prepared by a recently developed efficient multiscale approach based on the phase field crystal model. In contrast to previous works, our results show that the scaling of the thermal conductivity with the grain size implies bimodal behaviour with two effective Kapitza lengths. The scaling is dominated by the out-of-plane (flexural) phonons with a Kapitza length that is an order of magnitude larger than that of the in-plane phonons. We also show that in order to get quantitative agreement with the most recent experiments, quantum corrections need to be applied to both the Kapitza conductance of grain boundaries and the thermal conductivity of pristine graphene and the corresponding Kapitza lengths must be renormalized accordingly.Comment: Accepted to Nano Lett.; Numerical samples and computer codes availabl

BBBW on the spindle

We study the spindle compactification of families of AdS$_5$ consistent truncations corresponding to M5 branes wrapped on complex curves in Calabi-Yau three-folds. From the AdS/CFT correspondence these models are dual to $\mathcal{N}=1$ SCFTs obtained by gluing of $T_N$ blocks. The truncations considered here have both vector and hyper multiplets and the analysis of the BPS equations on the spindle allows to extract the central charges. Such analysis gives also consistency conditions for the existence of the solutions. The solutions are then found both analytically and numerically for opportune choices of the charges for some sub-families of truncations. We then compare our results with the one expected from the field theory side, by integrating the anomaly polynomial.Comment: 34 pages, 1 figur

Total Body Water Distribution in Breast Cancer Survivors Following Cancer Rehabilitation

Cancer in humans is frequently associated with compartmentalization of body fluids as a result of sedentary behavior and pharmacological cellular toxicity. Total Body Water (TBW) in the general population is approximately 55–60% of body weight in adult males and 50–55% in adult females, while varying significantly in pathological conditions. Exercise is largely recognized as an important tool to TBW distribution. The purpose of this study was to investigate, for a least 12 months, the impact of physical activity on body water distribution in a sample of cancer patients and compare their responses to a sample of healthy controls. Cancer patients included 28 clinically stable female cancer patients diagnosed with breast cancer (aged 59 ± 9 years, weight 70.2 ± 9.9 kg, and Body Mass Index (BMI 26.7 ± 5.4 kg·m ), who were enrolled in a year-long physical activity prescription program. The results indicated the absence of significant variations of TBW% between the cancer patients and controls, however, there was a significant improvement in intracellular water content (ICW%) at 6 months (T0: 51.1 ± 3.9 vs. T6: 52.4 ± 4.1; p \u3c 0.05) and at T12 (T0: 51.1 ± 3.9 vs. T12: 53.6 ± 3.1; p \u3c 0.005). In conclusion, in this small sample of cancer survivors, an unsupervised cancer rehabilitation program reduced the trend towards increased peripheral edema.

The addition of simvastatin administration to cold storage solution of explanted whole liver grafts for facing ischemia/reperfusion injury in an area with a low rate of deceased donation: a monocentric randomized controlled double-blinded phase 2 study.

BACKGROUND: Liver transplantation is the best treatment for end-stage liver disease. The interruption of the blood supply to the donor liver during cold storage damages the liver, affecting how well the liver will function after transplant. The drug Simvastatin may help to protect donor livers against this damage and improve outcomes for transplant recipients. The aim of this study is to evaluate the benefits of treating the donor liver with Simvastatin compared with the standard transplant procedure. PATIENT AND METHODS: We propose a prospective, double-blinded, randomized phase 2 study of 2 parallel groups of eligible adult patients. We will compare 3-month, 6-month, and 12-month graft survival after LT, in order to identify a significant relation between the two homogenous groups of LT patients. The two groups only differ by the Simvastatin or placebo administration regimen while following the same procedure, with identical surgical instruments, and medical and nursing skilled staff. To reach these goals, we determined that we needed to recruit 106 patients. This sample size achieves 90% power to detect a difference of 14.6% between the two groups survival using a one-sided binomial test. DISCUSSION: This trial is designed to confirm the effectiveness of Simvastatin to protect healthy and steatotic livers undergoing cold storage and warm reperfusion before transplantation and to evaluate if the addition of Simvastatin translates into improved graft outcomes. TRIAL REGISTRATION: ISRCTN27083228

Two-Photon Circularly Polarized Luminescence of Chiral Eu Complexes

We report the synthesis of chiral lanthanide complexes with extended π conjugation for efficient circularly polarized luminescence (CPL) via two-photon excitation (2PE). The pyridine bis-oxazoline (PyBox) core provides the chiral Ln3+ environment, while the extension of the conjugated backbone through the pyridine 4-position with a phenylacetylene unit increases the two-photon absorption cross section. This work presents an important step toward the development of chiral systems displaying enhanced nonlinear optical properties, with potential applications in imaging and sensing, as well as in photodynamic therapy due to the selective excitation of molecules within a specific focal volume

Case report: Trans-papillary free stenting of the cystic duct and of the common bile duct in a double biliary ducts anastomoses of a right lobe living donor transplantation

Background: One of the major issues related to the living donor liver transplantation recipient outcome is still the high rate of biliary complication, especially when multiple biliary ducts are present and multiple anastomoses have to be performed. Case presentation and conclusion: We report a case of adult-to-adult right lobe living donor liver transplantation performed for a recipient afected by alcohol-related cirrhosis with MELD score of 17. End-stage liver disease was complicated by refractory ascites, portal hypertension, small esophageal varices and portal gastropathy, hypersplenism, and abundant right pleural efusion. Here in the attached video we described the adult-to-adult LDLT procedures, where a right lobe with two biliary ducts draining respectively the right anterior and the right posterior segments has been transplanted. LDLT required a biliary reconstruction using the native cystic and common bile ducts stented trans-papillary with two 5- French 6 cm long soft silastic catheter. None major complications were detected during post-operative clinical courses. Actually, the donor and the recipient are alive and well. The technique we describe in the video, allow to keep the biliary anastomoses protected and patent without having the risk of creating cholestasis and the need of invasive additional procedure. No living donor right lobe transplantation should be refused because of the presence of multiple biliary ducts

Thermal conductivity decomposition in two-dimensional materials: Application to graphene

Two-dimensional materials have unusual phonon spectra due to the presence of flexural (out-of-plane) modes. Although molecular dynamics simulations have been extensively used to study heat transport in such materials, conventional formalisms treat the phonon dynamics isotropically. Here, we decompose the microscopic heat current in atomistic simulations into in-plane and out-of-plane components, corresponding to in-plane and out-of-plane phonon dynamics, respectively. This decomposition allows for direct computation of the corresponding thermal conductivity components in two-dimensional materials. We apply this decomposition to study heat transport in suspended graphene, using both equilibrium and nonequilibrium molecular dynamics simulations. We show that the flexural component is responsible for about two-thirds of the total thermal conductivity in unstrained graphene, and the acoustic flexural component is responsible for the logarithmic divergence of the conductivity when a sufficiently large tensile strain is applied

How important is the role of iterative liver direct surgery in patients with hepatocellular carcinoma for a transplant center located in an area with a low rate of deceased donation?

Introduction: Hepatocellular carcinoma (HCC) accounts for nearly 90% of primary liver cancers, with estimates of over 1 million people affected by 2025. We aimed to explore the impacting role of an iterative surgical treatment approach in a cohort of HCC patients within the Milan criteria, associated with clinical risk factors for tumor recurrence (RHCC) after liver transplant (LT) and loco-regional therapies (LRT), as well as liver resection (LR) and/or microwave thermal ablation (MWTA). Methods: We retrospectively analyzed our experience performed during an 8-year period between January 2013 and December 2021 in patients treated for HCC, focusing on describing the impact on preoperative end-stage liver disease severity, oncologic staging, tumor characteristics, and surgical treatments. The Cox model was used to evaluate variables that could predict relapse risks. Relapse risk curves were calculated according to the Kaplan-Meier method, and the log-rank test was used to compare them. Results: There were 557 HCC patients treated with a first-line approach of LR and/or LRTs (n = 335) or LT (n = 222). The median age at initial transplantation was 59 versus 68 for those whose first surgical approach was LR and/or LRT. In univariate analysis with the Cox model, nodule size was the single predictor of recurrence of HCC in the posttreatment setting (HR: 1.61, 95% CI: 1.05-2.47, p = 0.030). For the LRT group, we have enlightened the following clinical characteristics as significantly associated with RHCC: hepatitis B virus infection (which has a protective role with HR: 0.34, 95% CI: 0.13-0.94, p = 0.038), number of HCC nodules (HR: 1.54, 95% CI: 1.22-1.94, p < 0.001), size of the largest nodule (HR: 1.06, 95% CI: 1.01-1.12, p = 0.023), serum bilirubin (HR: 1.57, 95% CI: 1.03-2.40, p = 0.038), and international normalized ratio (HR: 16.40, 95% CI: 2.30-118.0, p = 0.006). Among the overall 111 patients with RHCC in the LRT group, 33 were iteratively treated with further curative treatment (12 were treated with LR, two with MWTA, three with a combined LR-MWTA treatment, and 16 underwent LT). Only one of 18 recurrent patients previously treated with LT underwent LR. For these RHCC patients, multivariable analysis showed the protective roles of LT for primary RHCC after IDLS (HR: 0.06, 95% CI: 0.01-0.36, p = 0.002), of the time relapsed between the first and second IDLS treatments (HR: 0.97, 95% CI: 0.94-0.99, p = 0.044), and the impact of previous minimally invasive treatment (HR: 0.28, 95% CI: 0.08-1.00, p = 0.051). Conclusion: The coexistence of RHCC with underlying cirrhosis increases the complexity of assessing the net health benefit of ILDS before LT. Minimally invasive surgical therapies and time to HCC relapse should be considered an outcome in randomized clinical trials because they have a relevant impact on tumor-free survival