Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa

Correction to: Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background: The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey, a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods: A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results: 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions: The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years

Diagnosis of Nipple Discharge: Value of Magnetic Resonance Imaging and Ultrasonography in Comparison with Ductoscopy

Background: Pathologic nipple discharge, which is a common reason for referral to the breast imaging service, refers to spontaneous or bloody nipple discharge that arises from a single duct. The most common cause of nipple discharge is benign breast lesions, such as solitary intraductal papilloma and papillomatosis. Nevertheless, in rare cases, a malignant cause of nipple discharge can be found. Aims: To study the diagnostic value of ultrasonography, magnetic resonance imaging, and ductoscopy in patients with pathologic nipple discharge, compare their efficacy, and investigate the importance of magnetic resonance imaging in the diagnosis of intraductal pathologies. Study Design: Diagnostic accuracy study. Methods: Fifty patients with pathologic nipple discharge were evaluated by ultrasonography and magnetic resonance imaging. Of these, 44 ductoscopic investigations were made. The patients were classified according to magnetic resonance imaging, ultrasonography, and ductoscopy findings. A total of 25 patients, whose findings were reported as intraductal masses, underwent surgery oincluding endoscopic excision for two endoscopic excision. Findings were compared with the pathology results that were accepted as the gold standard in the description of the aetiology of nipple discharge. In addition, magnetic resonance imaging, ultrasonography and ductoscopy findings were analysed comparatively in patients who had no surgery. Results: Intraductal masses were reported in 26 patients, 20 of whom operated and established accurate diagnosis of 18 patients on magnetic resonance imaging. According to the ultrasonography, intraductal masses were identified in 22 patients, 17 of whom underwent surgery. Ultrasonography established accurate diagnoses in 15 patients. Intraductal mass was identified in 22 patients and ductoscopy established accurate diagnoses based on histopathologic results in 16 patients. The sensitivities of methods were 75% in ultrasonography, 90% in magnetic resonance imaging, and 94.6% in ductoscopy. The specificities were 66.7% in ultrasonography, 66.7% in magnetic resonance imaging, and 40% in ductoscopy. Intraductal papillomas were mostly observed as oval nodules with well-circumscribed smooth margins within dilated ducts and persistant in the dynamic analysis. Lesions that protruded into the lumen of the ducts, either solitary or multiple, were characteristic ductoscopy findings of our patients who were diagnosed as having papilloma/papillomatosis. Conclusion: Magnetic resonance imaging and ductoscopy had no statistical superiority over each other, however they were superior to ultrasonography in the diagnosis of pathologic nipple discharge. Magnetic resonance imaging may be highly sensitive for diagnosing nipple discharge with new techniques and sequences and a non-invasive method that more advantageous for showing ductal tree visualization and is able to detect completely obstructed intraductal lesion

NF-kappa B and MAPKs are involved in resistin-caused ADAMTS-5 induction in human chondrocytes

Yaykasli, Emine/0000-0001-6471-0106; Yaykasli, Kursat/0000-0001-7550-6370; Bender, Onur/0000-0003-0691-3508WOS: 000359119100021Purpose: Chronic inflammation is an important etiological factor in the development of arthritic diseases. Several factors contribute to aggregation of chronic inflammation, including the presence of excess adipose tissue. Methods: The putative induction mechanisms of ADAMTS-5 by resistin were investigated in normal primary human articular chondrocytes. Expression levels of the ADAMTS-5 gene were determined at several resistin doses and durations. Results: Human chondrocytes were activated and associated with upregulated ADAMTS-5 gene expression after exposure to resistin (also known as adipose tissue-specific secretary factor, ADSF). Release of ADAMTS-5 leads to joint cartilage degradation, a key event in the development of arthritic diseases rheumatoid arthritis (RA) and osteoarthritis (OA). Activation of chondrocytes was associated with upregulated NF-kappa B protein levels in a time-dependent fashion. Co-incubation of human chondrocytes with JNK and p38 inhibitors lead to abrogated levels of NF-kappa B, indicating that these MAPKs are important in the activation of chondrocytes after stimulation with resistin. Similarly, ADAMTS-5 expression levels were abrogated when co-incubated with p38, NF-kappa B, JNK, MEK and PI3K inhibitors. Our results demonstrate that resistin, released from adipose tissue, may be involved in the development of RA and OA in obese patients through degradation of joint cartilage via ADAMTS-5 released from activated chondrocytes

NF-?B and MAPKs are involved in resistin-caused ADAMTS-5 induction in human chondrocytes

Purpose: Chronic inflammation is an important etiological factor in the development of arthritic diseases. Several factors contribute to aggregation of chronic inflammation, including the presence of excess adipose tissue. Methods: The putative induction mechanisms of ADAMTS-5 by resistin were investigated in normal primary human articular chondrocytes. Expression levels of the ADAMTS-5 gene were determined at several resistin doses and durations. Results: Human chondrocytes were activated and associated with upregulated ADAMTS-5 gene expression after exposure to resistin (also known as adipose tissue-specific secretary factor, ADSF). Release of ADAMTS-5 leads to joint cartilage degradation, a key event in the development of arthritic diseases rheumatoid arthritis (RA) and osteoarthritis (OA). Activation of chondrocytes was associated with upregulated NF-?B protein levels in a time-dependent fashion. Co-incubation of human chondrocytes with JNK and p38 inhibitors lead to abrogated levels of NF-?B, indicating that these MAPKs are important in the activation of chondrocytes after stimulation with resistin. Similarly, ADAMTS-5 expression levels were abrogated when co-incubated with p38, NF-?B, JNK, MEK and PI3K inhibitors. Our results demonstrate that resistin, released from adipose tissue, may be involved in the development of RA and OA in obese patients through degradation of joint cartilage via ADAMTS-5 released from activated chondrocytes. © 2015 CIM

Two years later: Is the SARS-CoV-2 pandemic still having an impact on emergency surgery? An international cross-sectional survey among WSES members

Background The SARS-CoV-2 pandemic is still ongoing and a major challenge for health care services worldwide. In the first WSES COVID-19 emergency surgery survey , a strong negative impact on emergency surgery (ES) had been described already early in the pandemic situation. However, the knowledge is limited about current effects of the pandemic on patient flow through emergency rooms, daily routine and decision making in ES as well as their changes over time during the last two pandemic years. This second WSES COVID-19 emergency surgery survey investigates the impact of the SARS-CoV-2 pandemic on ES during the course of the pandemic. Methods A web survey had been distributed to medical specialists in ES during a four-week period from January 2022, investigating the impact of the pandemic on patients and septic diseases both requiring ES, structural problems due to the pandemic and time-to-intervention in ES routine. Results 367 collaborators from 59 countries responded to the survey. The majority indicated that the pandemic still significantly impacts on treatment and outcome of surgical emergency patients (83.1% and 78.5%, respectively). As reasons, the collaborators reported decreased case load in ES (44.7%), but patients presenting with more prolonged and severe diseases, especially concerning perforated appendicitis (62.1%) and diverticulitis (57.5%). Otherwise, approximately 50% of the participants still observe a delay in time-to-intervention in ES compared with the situation before the pandemic. Relevant causes leading to enlarged time-to-intervention in ES during the pandemic are persistent problems with in-hospital logistics, lacks in medical staff as well as operating room and intensive care capacities during the pandemic. This leads not only to the need for triage or transferring of ES patients to other hospitals, reported by 64.0% and 48.8% of the collaborators, respectively, but also to paradigm shifts in treatment modalities to non-operative approaches reported by 67.3% of the participants, especially in uncomplicated appendicitis, cholecystitis and multiple-recurrent diverticulitis. Conclusions The SARS-CoV-2 pandemic still significantly impacts on care and outcome of patients in ES. Well-known problems with in-hospital logistics are not sufficiently resolved by now; however, medical staff shortages and reduced capacities have been dramatically aggravated over last two pandemic years