Giuseppe Pesce

Bio: Giuseppe Pesce is an academic researcher from University of Naples Federico II. The author has contributed to research in topics: Optical tweezers & Raman spectroscopy. The author has an hindex of 27, co-authored 97 publications receiving 2216 citations. Previous affiliations of Giuseppe Pesce include Istituto Nazionale di Fisica Nucleare & ARCO.

Spectroscopical and mechanical characterization of normal and thalassemic red blood cells by Raman Tweezers

Abstract: In this work, the effects of thalassemia, a blood disease quite diffuse in the Mediterranean sea region, have been investigated at single cell level using a Raman Tweezers system. By resonant excitation of hemoglobin Raman bands, we have examined the oxygenation capability of beta-thalassemic erythrocytes. A reduction of this fundamental erythrocyte function has been found. The measurements have been performed on a significant number of red blood cells; the relative statistical analysis is presented. Moreover, the response to photo-induced oxidative stress of diseased cells with respect to the normal ones has been analyzed. Finally, the deformability of thalassemic erythrocytes has been quantified by measuring the membrane shear modulus by using a double-trap system: the measurements have revealed an increase in membrane rigidity of more than 40%, giving evidence that the genetic defect associated to thalassemia, which manly relies on hemoglobin structure, also strongly affects the erythrocyte mechanical properties. Our results demonstrate that the developed set-up may have potential for the monitoring of blood diseases and their response to drug therapies.

Work and heat probability distribution of an optically driven Brownian particle: theory and experiments.

Abstract: We analyze the equations governing the evolution of distributions of the work and the heat exchanged with the environment by a manipulated stochastic system, by means of a compact and general derivation. We obtain explicit solutions for these equations for the case of a dragged Brownian particle in a harmonic potential. We successfully compare the resulting predictions with the outcomes of experiments, consisting of dragging a micron-sized colloidal particle through water with a laser trap.

Noninvasive diagnosis of small bowel Crohn's disease: direct comparison of bowel sonography and magnetic resonance enterography.

Abstract: Background: The diagnosis of small bowel Crohn’s disease (CD) is performed by ileocolonoscopy, whereas the assessment of its extension can be achieved by radiologic studies or, noninvasively, by magnetic resonance (MR) enterography and bowel sonography (BS). However, few comparative studies exist directly comparing the diagnostic accuracy of BS and MRI. The aim of this study was to evaluate the diagnostic accuracy of BS and MRI for the diagnosis of small bowel CD. Methods: We prospectively performed a noninferiority diagnostic study including 234 consecutive subjects with suspected small bowel CD. All patients underwent IC (used as gold standard for diagnosis), BS, and MR enterography performed in random order by physicians who were blinded about the results. Results: The diagnosis of small bowel CD was made in 120 of 249 subjects (48%). Sensitivity, specificity, positive predictive value, and negative predictive value for CD diagnosis were 94%, 97%, 97%, and 94% for BS and 96%, 94%, 94%, and 96% for MR enterography, respectively. BS was less accurate than MR enterography in defining CD extension (r ¼ 0.69), whereas the concordance in terms of CD location between the 2 procedures was high (k ¼ 0.81). Also, MRI showed a fair concordance with BS about strictures (k ¼ 0.82) and abscesses (k ¼ 0.88), with better detection of enteroenteric fistulas (k ¼ 0.67). Conclusions: BS and MR enterography are 2 accurate procedures for the diagnosis of small bowel CD, although MR seems to be more sensitive in defining its extension. BS could be used to select the patients for subsequent MRI examination. (Inflamm Bowel Dis 2013;0:1–8)

Optical tweezers — from calibration to applications: a tutorial

Abstract: Since their invention in 1986 by Arthur Ashkin and colleagues, optical tweezers have become an essential tool in several fields of physics, spectroscopy, biology, nanotechnology, and thermodynamics. In this tutorial, we provide a primer on how to calibrate optical tweezers and how to use them for advanced applications. After a brief general introduction on optical tweezers, we focus on describing and comparing the various available calibration techniques. Then, we discuss some cutting-edge applications of optical tweezers in a liquid medium, namely, to study single-molecule and single-cell mechanics, microrheology, colloidal interactions, statistical physics, and transport phenomena. Finally, we consider optical tweezers in vacuum, where the absence of a viscous medium offers vastly different dynamics and presents new challenges. We conclude with some perspectives for the field and the future applications of optical tweezers. This tutorial provides both a step-by-step guide ideal for non-specialists entering the field and a comprehensive manual of advanced techniques useful for expert practitioners. All of the examples are complemented by the sample data and software necessary to reproduce them.

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Stochastic thermodynamics, fluctuation theorems and molecular machines

Abstract: Stochastic thermodynamics as reviewed here systematically provides a framework for extending the notions of classical thermodynamics such as work, heat and entropy production to the level of individual trajectories of well-defined non-equilibrium ensembles. It applies whenever a non-equilibrium process is still coupled to one (or several) heat bath(s) of constant temperature. Paradigmatic systems are single colloidal particles in time-dependent laser traps, polymers in external flow, enzymes and molecular motors in single molecule assays, small biochemical networks and thermoelectric devices involving single electron transport. For such systems, a first-law like energy balance can be identified along fluctuating trajectories. For a basic Markovian dynamics implemented either on the continuum level with Langevin equations or on a discrete set of states as a master equation, thermodynamic consistency imposes a local-detailed balance constraint on noise and rates, respectively. Various integral and detailed fluctuation theorems, which are derived here in a unifying approach from one master theorem, constrain the probability distributions for work, heat and entropy production depending on the nature of the system and the choice of non-equilibrium conditions. For non-equilibrium steady states, particularly strong results hold like a generalized fluctuation–dissipation theorem involving entropy production. Ramifications and applications of these concepts include optimal driving between specified states in finite time, the role of measurement-based feedback processes and the relation between dissipation and irreversibility. Efficiency and, in particular, efficiency at maximum power can be discussed systematically beyond the linear response regime for two classes of molecular machines, isothermal ones such as molecular motors, and heat engines such as thermoelectric devices, using a common framework based on a cycle decomposition of entropy production. (Some figures may appear in colour only in the online journal) This article was invited by Erwin Frey.

Active Particles in Complex and Crowded Environments

Abstract: Differently from passive Brownian particles, active particles, also known as self-propelled Brownian particles or microswimmers and nanoswimmers, are capable of taking up energy from their environment and converting it into directed motion. Because of this constant flow of energy, their behavior can be explained and understood only within the framework of nonequilibrium physics. In the biological realm, many cells perform directed motion, for example, as a way to browse for nutrients or to avoid toxins. Inspired by these motile microorganisms, researchers have been developing artificial particles that feature similar swimming behaviors based on different mechanisms. These man-made micromachines and nanomachines hold a great potential as autonomous agents for health care, sustainability, and security applications. With a focus on the basic physical features of the interactions of self-propelled Brownian particles with a crowded and complex environment, this comprehensive review will provide a guided tour through its basic principles, the development of artificial self-propelling microparticles and nanoparticles, and their application to the study of nonequilibrium phenomena, as well as the open challenges that the field is currently facing.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Abstract: Ulcerative colitis and Crohn’s disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn’s and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn’s disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn’s disease, including patients, their families and friends.

The second European evidence-based Consensus on the diagnosis and management of Crohn's disease: Special situations

Abstract: Principal changes with respect to the 2004 ECCO guidelines Ileocolonoscopy is recommended within the first year after surgery where treatment decisions may be affected (Statement 8C). Thiopurines are more effective than mesalazine or imidazole antibiotics alone in post-operative prophylaxis (Statement 8F). ### 8.1 Epidemiology of post-operative Crohn's disease In the natural history of CD, intestinal resection is almost unavoidable since about 80% of patients require surgery at some stage. Surgery is unfortunately not curative as the disease inexorably recurs in many patients. The post-operative recurrence rate varies according to the definition used: clinical, endoscopic, radiological, or surgical. It is lowest when the repeat resection rate is considered, intermediate when clinical indices are used and highest when endoscopy is employed as the diagnostic tool.1–10 Data from endoscopic follow-up of patients after resection of ileo-caecal disease have shown that in the absence of treatment, the post-operative recurrence rate is around 65–90% within 12 months and 80–100% within 3 years of the operation. The clinical recurrence without therapy is about 20–25%/year.1,10 It has been demonstrated that the post-operative clinical course of CD is best predicted by the severity of endoscopic lesions. Symptoms, in fact, appear only when severe lesions are present and it is not uncommon to observe patients with fairly advanced recurrent lesions at endoscopy who remain asymptomatic.1 For these reasons, clinical indices such as the CDAI have low sensitivity at discriminating between patients with or without post-operative recurrence.11 These data mandate strategies aimed at interrupting or delaying the natural course of post-operative recurrence. Several medications have been tried in an attempt to prevent post-operative recurrence, mostly with disappointing results. The aim of this Consensus was therefore critically to evaluate the optimal strategies for the management of post-operative recurrence in CD. Most, if not all, of the evidence available deals with …