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Cesium methylammonium lead iodide (CsxMA1−xPbI3) nanocrystals were obtained with a wide range of A‐site Cs‐MA compositions by post‐synthetic, room temperature cation exchange between CsPbI3 nanocrystals and MAPbI3 nanocrystals. The alloyed CsxMA1−xPbI3 nanocrystals retain their photoactive perovskite phase with incorporated Cs content, x, as high as 0.74 and the expected composition‐tunable photoluminescence (PL). Excess methylammonium oleate from the reaction mixture in the MAPbI3 nanocrystal dispersions was necessary to obtain fast Cs‐MA cation exchange. The phase transformation and degradation kinetics of films of CsxMA1−xPbI3 nanocrystals were measured and modeled using an Avrami expression. The transformation kinetics were significantly slower than those of the parent CsPbI3 and MAPbI3 nanocrystals, with Avrami rate constants, k, at least an order of magnitude smaller. These results affirm that A‐site cation alloying is a promising strategy for stabilizing iodide‐based perovskites. [ABSTRACT FROM AUTHOR]

Byline: Omar F. Aly, A.H.P. Andrade, M. Mattar Neto One of the main deterioration modes that cause risks to pressurised water reactors is the Primary Water Stress Corrosion Cracking (PWSCC) at the Control Rod Drive Mechanism (CRDM) nozzles in the reactor pressure vessel. These cracks can cause accidents that reduce nuclear safety, and/or leakage of primary water. In this paper, preliminary modelling to predict these failures is proposed. The potential-pH diagram for Alloy 600 on primary water at high temperature is assumed. Over it is marked the region where the PWSCC cracks can initiate and propagate. Later, a comparative model is superimposed based on strength fraction to PWSCC, a strain rate damage model and a semi-empirical one that can describe the time of failure. Some preliminary results are presented and discussed. These models are adequate for using experimental data to be obtained from Slow Strain Rate Testing (SSRT) at the CDTN-Development Center of Nuclear Technology, Belo Horizonte, Brazil.

Cesium methylammonium lead iodide (Cs x MA 1-x PbI 3 ) nanocrystals were obtained with a wide range of A-site Cs-MA compositions by post-synthetic, room temperature cation exchange between CsPbI 3 nanocrystals and MAPbI 3 nanocrystals. The alloyed Cs x MA 1-x PbI 3 nanocrystals retain their photoactive perovskite phase with incorporated Cs content, x, as high as 0.74 and the expected composition-tunable photoluminescence (PL). Excess methylammonium oleate from the reaction mixture in the MAPbI 3 nanocrystal dispersions was necessary to obtain fast Cs-MA cation exchange. The phase transformation and degradation kinetics of films of Cs x MA 1-x PbI 3 nanocrystals were measured and modeled using an Avrami expression. The transformation kinetics were significantly slower than those of the parent CsPbI 3 and MAPbI 3 nanocrystals, with Avrami rate constants, k, at least an order of magnitude smaller. These results affirm that A-site cation alloying is a promising strategy for stabilizing iodide-based perovskites., (© 2023 Wiley-VCH GmbH.)

Background: Squamous cell carcinoma of the cheek is a locoregionally aggressive tumor. Radical resection may be curative in cases of large tumor without distant metastases. We reviewed forty eight consecutive cases of Sq.c.c. of the oral cavity to evaluate the feasibility and efficacy of the reconstructive method., Patients and Methods: Forty eight cases of invasive Sq.c.c. affecting the cheek performed in Mansoura University, Surgical Oncology Department. From November 2001 to October 2004 were included. Twenty cafes presented primarily, and 28 were relapsing after previous surgery or radiotherapy. Tumors of T3 and T4 size were included. Radical excision with adequate safety margin followed by reconstruction was done in the same setting using: A- Double layered pectoralis major flap (n=30). B- Pectoralis major flap for external surface and tongue flap for mucosal lining (n=10). C- Pectoralis major flap plus free Latissmus dorsi flap (n=3). D- Latissmus dorsi flap plus tongue flap (n=5)., Results: Nine cases (18.7%) had local and distant relapse after a median follow up period of 36 months. However, total flap loss was not encountered. There were partial loss of three tongue flaps, seven pectoralis flaps corrected with debridement and reapproximation. Two patients had oral incompetence. Orocutaneous salivary fistula persistent more than three weeks occurred in eight patients. Functional outcome in terms of oral competence, sensibility, chewing movements was satisfactory in all but three cases., In Conclusion: Radical resection of extensive cheek carcinoma and reconstruction using pedicled flaps is an effective, economic and reliable method for oncologic and functional purposes.

Background: Squamous cell carcinoma of the head and neck is a challenging disease to both surgeons and radiation oncologists due to proximity of many important anatomical structures. Surgery could be curative as these cancers usually metastasize very late by blood stream., Aim of the Work: This work addresses the oncologic, functional and aesthetic factors affecting reconstruction of large orofacial defects involving the lip following tumor resection., Patients and Methods: The study reviews the surgical outcome of one hundred and twelve patients with invasive tumors at, or extending to, the lip(s), treated at the Mansoura University-Surgical Oncology Department, from January 2000 to January 2005. Tumor stage were T2 (43), T3 (56) and T4 (13). Nodal state was N0 in 80, N1 in 29 and N2 in three cases. AJCC stage grouping was II (T2N0) in 33 patients, stage III (T3N0 or T1-3N1) in 64 cases and stage IV (T4 due to bone erosion or N2) in 15 cases. The technique used for lip reconstruction was: Unilateral or bilateral myocutaneous depressor anguli oris flap (MCDAOF) for isolated lip defect (n=63). Bilateral myocutaneous depressor anguli oris (MCDAOF) plus local cervical rotational flap chin defects (n=3). Pectoralis major myocutaneous pedicled flap for cheek defects involving the lip together with a tongue flap for mucosal reconstruction (n=35). Sternocleidomastoid clavicular myo-osseous flap for concomitant mandibular defects (n=12)., Results: Aesthetic and functional results are evaluated regarding appearance, oral incompetence, disabling microstomia and eating difficulties. Depressor anguli oris reconstruction allowed functioning static and dynamic oral function in all cases in contrast to the Pectorails major flap. There were 18 cases of oral incompetence (46.1%), nine cases of speech difficulty (23%) and five patients with poor cosmetic appearance within the second group. Total flap loss was not encountered, Partial flap loss affected thirteen depressor anguli oris flaps (21.3%) and six pectoral flaps (15.3%).