Multiscale Modeling of a Nanoelectromechanical Shuttle

In this article, we report a theoretical analysis of a nanoelectromechanical shuttle based on a multiscale model that combines microscopic electronic structure data with macroscopic dynamics. The microscopic part utilizes a (static) density functional description to obtain the energy levels and orbitals of the shuttling particle together with the forces acting on the particle. The macroscopic part combines stochastic charge dynamics that incorporates the microscopically evaluated tunneling rates with a Newtonian dynamics. We have applied the multiscale model to describe the shuttling of a single copper atom between two gold-like jellium electrodes. We find that energy spectrum and particle surface interaction greatly influence shuttling dynamics; in the specific example that we studied the shuttling is found to involve only charge states Q=0 and Q=+e. The system is found to exhibit two quasi-stable shuttling modes, a fundamental one and an excited one with a larger amplitude of mechanical motion, with random transitions between them.Comment: 9 pages, 9 figure

Quantum gate algorithm for reference-guided DNA sequence alignment

Reference-guided DNA sequencing and alignment is an important process in computational molecular biology. The amount of DNA data grows very fast, and many new genomes are waiting to be sequenced while millions of private genomes need to be re-sequenced. Each human genome has 3.2 B base pairs, and each one could be stored with 2 bits of information, so one human genome would take 6.4 B bits or about 760 MB of storage (National Institute of General Medical Sciences). Today most powerful tensor processing units cannot handle the volume of DNA data necessitating a major leap in computing power. It is, therefore, important to investigate the usefulness of quantum computers in genomic data analysis, especially in DNA sequence alignment. Quantum computers are expected to be involved in DNA sequencing, initially as parts of classical systems, acting as quantum accelerators. The number of available qubits is increasing annually, and future quantum computers could conduct DNA sequencing, taking the place of classical computing systems. We present a novel quantum algorithm for reference-guided DNA sequence alignment modeled with gate-based quantum computing. The algorithm is scalable, can be integrated into existing classical DNA sequencing systems and is intentionally structured to limit computational errors. The quantum algorithm has been tested using the quantum processing units and simulators provided by IBM Quantum, and its correctness has been confirmed.Comment: 19 pages, 13 figure

Mixed cation effect in chalcogenide glasses Rb2S-Ag2S-GeS2

Journal URL: http://prb.aps.org

Primary hepatocellular carcinoma in a patient with history of treated breast cancer: a case report with challenging diagnosis and treatment

Christoforos Kosmidis,1 Nikolaos Varsamis,1 Georgios Anthimidis,1 Sofia Baka,2 Dimitrios Valoukas,3 Triantafyllia Koletsa,4 Katerina Zarampouka,4 Georgios Koimtzis,5 Eleni Georgakoudi,6 Paul Zarogoulidis,7 Christoforos Efthymiadis1 1Department of Surgery, Interbalkan European Medical Center, Thessaloniki, Greece; 2Department of Oncology, Interbalkan European Medical Center, Thessaloniki, Greece; 3Department of Oncology, General Hospital of Ptolemaida, Ptolemaida, Greece; 4Pathology Department, Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece; 5Third Surgical Department, Faculty of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece; 6Aristotle University of Thessaloniki, Thessaloniki, Greece; 7Pulmonary-Oncology Unit, “Theageneio” Cancer Hospital, Thessaloniki, Greece Introduction: Breast cancer is the most common malignancy in women worldwide. Long-term survivors among patients treated for breast cancer are at a high risk for developing a second primary malignancy. Hepatocellular carcinoma is the most frequent primary hepatic malignancy and should be ruled out in breast cancer patients who are diagnosed with solitary hepatic lesions. False diagnosis may lead to inappropriate oncologic staging and treatment of the disease. Case presentation: We present the case of a 73-year-old female patient who had been treated for invasive ductal breast cancer 7 years ago and was diagnosed with a solid hepatic lesion at segments VI and VII and a small, calcified lesion at the tail of the pancreas on follow-up with an abdominal computed tomography. Oncology council decided that both lesions could be resected after determining whether they were metastatic or second primary malignancies. The patient underwent laparotomy and rapid biopsy which showed primary hepatocellular carcinoma and fibrosis of the pancreas. We performed hepatic segmentectomy (VI–VII) and cholecystectomy, while the pancreatic lesion was left intact. The postoperative course of the patient was uncomplicated and she remains disease free 2 years after the operation without any adjuvant therapy. Conclusion: All hepatic lesions detected in breast cancer patients should be evaluated with open mind and liver biopsy should be performed to get a definitive diagnosis and implement the proper treatment strategy. Keywords: breast cancer, hepatocellular cancer, second primary malignancy, rapid biopsy, microwave tissue coagulato