Study of electro-absorption effects in 1300nm In(Ga)As/GaAs quantum dot materials

No abstract available

Radiative Heat Transfer Modeling in Fibrous Porous Media

Phenolic-Impregnated Carbon Ablator (PICA) was developed at NASA Ames Research Center as a lightweight thermal protection system material for successful atmospheric entries. The objective of the current work is to compute the effective radiative conductivity of fibrous porous media, such as preforms used to make PICA, to enable the efficient design of materials that can meet the thermal performance goals of forthcoming space exploration missions

Microscale Modeling of High-Temperature Heat Transfer in Anisotropic Porous Materials

No abstract availabl

Incorporating Structural Analysis in a Quantum Dot Monte-Carlo Model

We simulate the shape of the density of states (DoS) of the quantum dot (QD) ensemble based upon size information provided by high angle annular dark field scanning transmission electron microscopy (HAADF STEM). We discuss how the capability to determined the QD DoS from micro-structural data allows a MonteCarlo model to be developed to accurately describe the QD gain and spontaneous emission spectra. The QD DoS shape is then studied, with recommendations made via the effect of removing, and enhancing this size inhomogeneity on various QD based devices is explored

Electrochemical determination of the antipsychotic medication clozapine by a carbon paste electrode modified with a nanostructure prepared from titania nanoparticles and copper oxide

A nanostructure was prepared from titania nanoparticles and copper oxide (TiO2NP@CuO) and used to modify a carbon paste electrode (CPE). The modified CPE is shown to enable sensitive voltammetric determination of the drug clozapine (CLZ). The sensor was characterized by various techniques and some key parameters were optimized. Under the optimum conditions and at a working potential of 0.6 V (vs. Ag/AgCl), the modified CPE has two linear response ranges, one from 30 pmol L�1 to 4 nmol L�1 of CLZ, the other from 4 nmol L�1 to 10 μmol L�1. The detection limit is as low as 9 pM. The transfer coefficient (α) and catalytic rate constant (kcat) were calculated and the reliability of the sensor was estimated for CLZ sensing in real samples where it gave satisfactory results. Figure not available: see fulltext.. © 2019, Springer-Verlag GmbH Austria, part of Springer Nature

Lenvatinib for the treatment of renal cell carcinoma

Introduction: Renal cell carcinoma (RCC) accounts for 2\u20133% of all solid tumors. Expression of the receptor for the vascular endothelial growth factor (VEGF) is one of the most common features of RCC. Areas covered: Lenvatinib is a novel multi-kinase inhibitor that has been studied in several solid tumors. It has shown promising results in the treatment of RCC, especially when combined with everolimus, In this review, we summarize the available data of lenvatinib for the treatment of advanced/metastatic renal cell carcinoma. Expert opinion: Lenvatinib in combination with everolimus has provided encouraging results in both clinical and laboratory investigations showing that blocking angiogenesis and the mTOR signalling pathway could be a remarkable approach for treating RCC. As an additive to this type of approach it would be interesting in future clinical settings testing also the combination of lenvatinib and everolimus with immune-therapy

Predictors of mortality following emergency open colectomy for ischemic colitis: A single-center experience

Background: Ischemic colitis (IC) is a severe emergency in gastrointestinal surgery. The aim of the present study was to identify the predictors of postoperative mortality after emergent open colectomy for IC treatment. Additionally, we compared postoperative outcomes of patients undergoing emergent colectomy due to aortic surgery-related IC (AS-IC group) vs. other IC etiologies (Other-IC group). Methods: We analyzed records of consecutive patients who underwent emergency open colectomy for IC between 2008 and 2019. Logistic regression analysis was performed to identify clinical and operative parameters associated with postoperative mortality. The AS-IC and Other-IC groups were compared for mortality, morbidity, ICU stay, hospital stay, and survival. Results: During the study period, 94 patients (mean age, 67.4 ± 13.7 years) underwent emergent open colectomy for IC. In the majority of cases, IC involved the entire colon (53.2%) and vasopressor agents were required preoperatively (63.8%) and/or intraoperatively (78.8%). Thirty-four patients underwent surgery due to AS-IC, whereas 60 due to Other-IC causes. In the AS-IC group, 9 patients had undergone endovascular aortic repair and 25 open aortic surgery; 61.8% of patients needed aortic surgery for ruptured abdominal aortic aneurism (AAA). Overall, 66 patients (70.2%) died within 90 days from surgery. The AS-IC and Other-IC groups showed similar operative outcomes and postoperative complication rates. However, the duration of the ICU stay (19 days vs. 11 days; p = 0.003) and of the total hospital stay (22 days vs. 16 days; p = 0.016) was significantly longer for the AS-IC group than for the Other-IC group. The rate of intestinal continuity restoration at 1 year after surgery was higher for the Other-IC group than for the AS-IC group (58.8% vs. 22.2%; p = 0.05). In the multivariate model, preoperative increased lactate levels, a delay between signs/symptoms' onset and surgery > 12 h, and the occurrence of postoperative acute kidney injury were statistically associated with postoperative mortality. Neither IC etiology (aortic surgery vs. other etiology) nor ruptured AAA was associated with postoperative mortality. Conclusion: Emergency open colectomy for IC is associated with high postoperative mortality, which appears to be unrelated to the IC etiology. Preoperative lactate levels, > 12-h delay to surgery, and postoperative acute kidney injury are independent predictors of postoperative mortality

Robotic multiquadrant colorectal procedures: A single-center experience and a systematic review of the literature

Purpose: Robotic surgery has been progressively implemented for colorectal procedures but is still limited for multiquadrant abdominal resections. The present study aims to describe our experience in robotic multiquadrant colorectal surgeries and provide a systematic review and meta-analysis of the literature investigating the outcomes of robotic total proctocolectomy (TPC), total colectomy (TC), subtotal colectomy (STC), or completion proctectomy (CP) compared to laparoscopy. Methods: At our institution 16 consecutive patients underwent a 2- or 3-stage totally robotic total proctocolectomy (TPC) with ileal pouch-anal anastomosis. A systematic review of the literature was performed to select studies on robotic and laparoscopic multiquadrant colorectal procedures. Meta-analyses were used to compare the two approaches. Results: In our case series, 14/16 patients underwent a 2-stage robotic TPC for ulcerative colitis with a mean operative time of 271.42 (SD:37.95) minutes. No conversion occurred. Two patients developed postoperative complications. The mean hospital stay was 8.28 (SD:1.47) days with no readmissions. Mortality was nil. All patients underwent loop-ileostomy closure, and functional outcomes were satisfactory. The literature appraisal was based on 23 retrospective studies, including 736 robotic and 9,904 laparoscopic multiquadrant surgeries. In the robotic group, 36 patients underwent STC, 371 TC, 166 TPC, and 163 CP. Pooled data analysis showed that robotic TC and STC had a lower conversion rate (OR = 0.17;95% CI, 0.04–0.82; p = 0.03) than laparoscopic TC and STC. The robotic approach was associated with longer operative time for TC and STC (MD = 104.64;95% CI, 18.42–190.87; p = 0.02) and TPC and CP (MD = 38.8;95% CI, 18.7–59.06; p = 0.0002), with no differences for postoperative complications and hospital stay. Reports on urological outcomes, sexual dysfunction, and quality of life were missing. Conclusions: Our experience and the literature suggest that robotic multiquadrant colorectal surgery is safe and effective, with low morbidity and mortality rates. Nevertheless, the overall level of evidence is low, and functional outcomes of robotic approach remain largely unknown. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42022303016