Direct Measurement of Surfactant-Mediated Picoforces among Nanoparticles in a Quasi-Two-Dimensional Environment.

The lack of methodologies which enable us to measure forces acting between nanomaterials is one of the factors limiting the full comprehension of their behavior and their more effective exploitation in new devices. Here we exploit the irreversible adsorption of surfactant-decorated nanoparticles at the air/water interface to investigate interparticle forces and the effect of the surfactant structure on them. We measured the interparticle repulsive forces as a function of the modulation of the interparticle distance by simultaneously performing compression isotherms and the grazing incidence small-angle X-ray scattering (GISAXS) structural characterization of the monolayers at water-vapor interfaces. Our results demonstrate that the short-range interparticle forces are strongly affected by the presence of the organic ligands, which are shown to be able to influence the interparticle repulsions even when added in micromolar amounts. In particular, we demonstrate the predominant steric nature of short-range forces, which are accounted for in terms of the compression-induced stretched-to-coiled conformational transition of the ligand hydrophobic tail.

Epigenetic Aging and Colorectal Cancer: State of the Art and Perspectives for Future Research.

Although translational research has identified a large number of potential biomarkers involved in colorectal cancer (CRC) carcinogenesis, a better understanding of the molecular pathways associated with biological aging in colorectal cells and tissues is needed. Here, we aim to summarize the state of the art about the role of age acceleration, defined as the difference between epigenetic age and chronological age, in the development and progression of CRC. Some studies have shown that accelerated biological aging is positively associated with the risk of cancer and death in general. In line with these findings, other studies have shown how the assessment of epigenetic age in people at risk for CRC could be helpful for monitoring the molecular response to preventive interventions. Moreover, it would be interesting to investigate whether aberrant epigenetic aging could help identify CRC patients with a high risk of recurrence and a worst prognosis, as well as those who respond poorly to treatment. Yet, the application of this novel concept is still in its infancy, and further research should be encouraged in anticipation of future applications in clinical practice.

Supramolecular Sensing of a Chemical Warfare Agents Simulant by Functionalized Carbon Nanoparticles.

Real-time sensing of chemical warfare agents by optical sensors is today a crucial target to prevent terroristic attacks by chemical weapons. Here the synthesis, characterization and detection properties of a new sensor, based on covalently functionalized carbon nanoparticles, are reported. This nanosensor exploits noncovalent interactions, in particular hydrogen bonds, to detect DMMP, a simulant of nerve agents. The nanostructure of the sensor combined with the supramolecular sensing approach leads to high binding constant affinity, high selectivity and the possibility to reuse the sensor.

In situ structure and force characterization of 2D nano-colloids at the air/water interface.

The control of self-assembly and the related interactions among nanoparticles (NPs) at liquid surfaces and interfaces represents a stimulating experimental challenge to fully understand the behaviour of nano-colloids confined in a 2D asymmetric environment, in turn prompting the building of novel NP-based functional monolayers. Here, we first investigate the structural evolution of a model mixed surfactant/NP monolayer as a function of the surfactant/NP bulk ratio finding that, at ratios lower than 20, the adsorption at the air/water interface of surfactant-decorated NPs is dominant. We then employed these 2D nano-colloidal monolayers as model systems for grazing incidence small angle X-ray scattering measurements, performed using synchrotron radiation, while compressing the monolayers in a Langmuir trough. The simultaneous determination of the compression work and the related reduction of the inter-particle distance at the interface enabled, for the first time, the quantitative characterization of the forces acting between adsorbed NPs, as well as their dispersion law with the inter-particle distance. Distinct surfactant reorganization processes are proposed to interpret the measured forces and the characteristic inter-particle distances.

Reactive nanomessengers for artificial chemical communication.

Artificial chemical communication is an emerging field of study driven by the need of exchanging information in delicate environments where standard procedures based on electromagnetic waves cannot be used. A non-synchronized artificial chemical communication system, based on a new modulation technique, namely reaction shift keying (RSK), is presented. The RSK implies that the quenchers are injected into the transmitter, the chemical messenger reacts and a chemically modified messenger travels towards the receiver. Encoding of "0" is obtained by means of the emission of a messenger that reaches the receiver once chemically modified. To encode the value "1", the messenger is not subjected to chemical reaction. Fluorescent carbon nanoparticle molecular messengers that exploit the reaction with Cu(ii) ions for signal modulation were synthesized. A prototypal RSK modulated chemical communication system is developed, from simulations of the communication platform to an operating prototypal system.

Epigenetic Biomarkers in Colorectal Cancer Patients Receiving Adjuvant or Neoadjuvant Therapy: A Systematic Review of Epidemiological Studies.

Colorectal cancer (CRC) represents the third-most common cancer worldwide and one of the main challenges for public health. Despite great strides in the application of neoadjuvant and adjuvant therapies for rectal and colon cancer patients, each of these treatments is still associated with certain adverse effects and different response rates. Thus, there is an urgent need for identifying novel potential biomarkers that might guide personalized treatments for specific subgroups of patients. However, until now, there are no biomarkers to predict the manifestation of adverse effects and the response to treatment in CRC patients. Herein, we provide a systematic review of epidemiological studies investigating epigenetic biomarkers in CRC patients receiving neoadjuvant or adjuvant therapy, and their potential role for the prediction of outcomes and response to treatment. With this aim in mind, we identified several epigenetic markers in CRC patients who received surgery with adjuvant or neoadjuvant therapy. However, none of them currently has the robustness to be translated into the clinical setting. Thus, more efforts and further large-size prospective studies and/or trials should be encouraged to develop epigenetic biomarker panels for personalized prevention and medicine in CRC cancer.

Driving Coordination Polymer Monolayer Formation by Competitive Reactions at the Air/Water Interface.

We have developed a novel approach enabling us to follow and facilitate the formation of two-dimensional coordination polymer monolayers directly at the air/water interface without the need of complex instrumentation. The method is based on the use of a surface active ligand that, when spread at the air/water interface, progressively undergoes hydrolysis with consequent gradual decrease in surface pressure. Notably, if the aqueous subphase contains metal ions capable of coordinating the ligand, coordination competes with hydrolysis, resulting in a lower surface pressure decrease. As a consequence, the formation of the coordination polymer monolayer can be verified simply by surface pressure measurements. Competition between hydrolysis and coordination was investigated as a function of the main experimental parameters affecting the two reactions, enabling the formation of stable coordination polymer monolayers with controlled density. Finally, the formation of continuous rigid 2D layers was confirmed by compression isotherms and ex situ morphological characterization. This work will simplify the verification of coordination polymer monolayer formation; thus, it will boost the synthesis of novel and innovative 2D materials.

Reactive messengers for digital molecular communication with variable transmitter-receiver distance.

Molecular communication exploits functional molecular systems travelling along fluid media to deliver messages encoded as concentration pulses, e.g. molecular bits. As the bits are naturally broadened by diffusion, limiting the distance along which information can be transferred, by careful design and optimization of the molecular messengers, is required. A new paradigm, exploiting the chemical reactivity of a suitable molecular messenger, has been developed to achieve long range information transfer with variable transmitter-receiver distances. The experimental results and theoretical simulations, carried out by using fluorescent molecules switched by pH-driven hydrolysis, are reported here. In particular, we simulated the information transport process by using numerical solutions of differential equations governing information swapping and we show that by exploiting the reactivity of the chemical messenger, a stable signal at the receiver is maintained within a wide range of distance. This theoretical prediction was fully experimentally verified by using a prototypal molecular communication platform.

Real Space Imaging of Nanoparticle Assembly at Liquid-Liquid Interfaces with Nanoscale Resolution.

Bottom up self-assembly of functional materials at liquid-liquid interfaces has recently emerged as method to design and produce novel two-dimensional (2D) nanostructured membranes and devices with tailored properties. Liquid-liquid interfaces can be seen as a "factory floor" for nanoparticle (NP) self-assembly, because NPs are driven there by a reduction of interfacial energy. Such 2D assembly can be characterized by reciprocal space techniques, namely X-ray and neutron scattering or reflectivity. These techniques have drawbacks, however, as the structural information is averaged over the finite size of the radiation beam and nonperiodic isolated assemblies in 3D or defects may not be easily detected. Real-space in situ imaging methods are more appropriate in this context, but they often suffer from limited resolution and underperform or fail when applied to challenging liquid-liquid interfaces. Here, we study the surfactant-induced assembly of SiO2 nanoparticle monolayers at a water-oil interface using in situ atomic force microscopy (AFM) achieving nanoscale resolved imaging capabilities. Hitherto, AFM imaging has been restricted to solid-liquid interfaces because applications to liquid interfaces have been hindered by their softness and intrinsic dynamics, requiring accurate sample preparation methods and nonconventional AFM operational schemes. Comparing both AFM and grazing incidence X-ray small angle scattering data, we unambiguously demonstrate correlation between real and reciprocal space structure determination showing that the average interfacial NP density is found to vary with surfactant concentration. Additionally, the interaction between the tip and the interface can be exploited to locally determine the acting interfacial interactions. This work opens up the way to studying complex nanostructure formation and phase behavior in a range of liquid-liquid and complex liquid interfaces.

The Link Between Self-Assembly and Molecular Conformation of Amphiphilic Block Copolymers Monolayers at the Air/Water Interface: The Spreading Parameter.

Two amphiphilic block copolymers, namely polystyrene-b-poly(methyl-methacrylate) (PS-b-PMMA), at the air/water interface were studied combining the in situ structural characterization, by means of X-ray reflectivity (XRR) and grazing incidence small-angle X-ray scattering (GISAXS), and the ex situ morphological one, by atomic force microscopy (AFM). We observed that the conformation of the hydrophilic block spread on the water surface is dramatically influenced by the morphology of the monolayer. Our results showed that the hydrophilic PMMA block adopts an expanded conformation when thermodynamically stable nanodots are formed, whereas a coiled conformation is observed when the block copolymer formed kinetically frozen nanostrands. This effect is interpreted in terms of the spreading parameter, which changes with the relative length ratio between the two blocks. Finally, we proved that, even for block copolymer monolayer with fixed block length ratio, it is possible to change the morphology, and in turn the conformation of the hydrophilic block, by changing the spreading parameter value.

Structure-rheology relationship in weakly amphiphilic block copolymer Langmuir monolayers.

The linear viscoelastic behavior in the low-frequency regime at the water/air interface of three different polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) copolymer monolayers, with block length ratio varying from 66-33 to 50-50 and 25-75 in molecular units, was studied and related to the interfacial behavior, characterized by means of Langmuir isotherms, and their structure, characterized by means of the atomic force microscopy technique. The two monolayers with the highest PMMA amount showed a single phase transition at about 12 mN/m, the viscoelastic behavior changing from a predominantly elastic to a viscoelastic one. This change in the viscoelastic properties was ascribed to the beginning of entanglement among the PMMA coronas of the predominantly circular quasi-2D micelles formed by the two copolymer systems. Conversely, the polymer with the lowest PMMA amount, despite having the same PMMA block length of the PS-PMMA 50-50 block copolymer, was found to behave as a viscoelastic system at any surface pressure value. This characteristic behavior cannot therefore be simply related to the molecular weight difference, but it has been put in connection to the irregular micelle structure observed in this case, consisting of a mixture of spherical and wormlike micelles, and to the different conformation adopted by the PMMA block. By blending this copolymer with an immiscible elastic homopolymer, namely poly(2-vinylpyridine), it was possible to tune the micelle nanostructure, obtaining regular circular quasi-2D micelles, with viscoelastic properties as expected for the PMMA-rich copolymer monolayers. To the best of our knowledge, this study shows for the first time the explicit dependence upon the relative block length and, in turn, upon the nanostructure of the quasi-2D micelles, of the viscoelastic properties of Langmuir monolayers and suggests that molecular weight and intermolecular interactions are not the only parameters governing the polymer conformation and, in turn, the polymer rheology and dynamics in quasi-2D confined systems.

Modulating Polymer Ultrathin Film Crystalline Fraction and Orientation with Nanoscale Curvature.

We investigated the effect of nanoscale curvature on the structure of thermally equilibrated poly-3-hexylthiophene (P3HT) ultrathin films. The curvature-induced effects were investigated with synchrotron grazing incidence X-ray diffraction (GIXRD) and atomic force microscopy (AFM). Our results demonstrate that nanoscale curvature reduces the polymer crystalline fraction and the crystal length. The first effect is strongest for the lowest curvature and results in a decrease in the out-of-plane thickness of the polymer crystals. On the other hand, the crystal in-plane length decreases with the increase in substrate curvature. Finally, the semi-quantitative analysis of crystal anisotropy shows a marked dependence on the substrate curvature characterized by a minimum at curvatures between 0.00851 nm-1 and 0.0140 nm-1. The results are discussed in terms of a curvature-dependent polymer fraction, which fills the interstices between neighboring particles and cannot crystallize due to extreme space confinement. This fraction, whose thickness is highest at the lowest curvatures, inhibits the crystal nucleation and the out-of-plane crystal growth. Moreover, because of the adhesion to the curved portion of the substrates, crystals adopt a random orientation. By increasing the substrate curvature, the amorphous fraction is reduced, leading to polymer films with higher crystallinity. Finally, when the thickness of the film exceeds the particle diameter, the curvature no longer affects the crystal orientation, which, similarly to the flat case, is predominantly edge on.

Bile duct injury during laparoscopic cholecystectomy without intraoperative cholangiography: a retrospective study on 1,100 selected patients.

BACKGROUND: Whether to routinely or selectively use intraoperative cholangiography (IOC) during laparoscopic cholecystectomy (LC) has been a controversial issue for many years. Many authors maintain that IOC decreases the rate of biliary complications such as bile duct injuries, biliary leak, and missed common bile duct (CBD) stones. However, in contrast to these claims, many centers have opted to perform LC without IOC. In this retrospective study, the results of a series of 1,100 LCs, all of which involved major biliary complications and which were performed without the use of IOC, were reviewed. METHODS: Data from 1,100 selected patients (728 females and 372 males) undergoing LC without the use of IOC from January 2003 to November 2011 were analyzed. One hundred and seventy LCs were performed by young surgeons during the learning curve, and 930 by surgeons with over 10 years of experience. Two techniques were used to create pneumoperitoneum: the Veress technique in 319 cases (29%) and the Hasson technique in the remaining 781 cases (71%). Patients with a suspicion of CBD stones were excluded from the study. RESULTS: Two CBD injuries (0.18%) and three biliary leaks (0.27%) were detected among this group. Thirty-three patients (3%) needed conversion to open cholecystectomy. Missed CBD stones were reported in 4 cases (0.36%). There was no postoperative mortality. CONCLUSION: LC can be performed safely without the use of IOC and with acceptable low rates of biliary complications. An accurate preoperative evaluation of clinical risk factors, precise operative procedures, and conversion to an open approach in doubtful cases are important measures which must be taken to prevent CBD injury.

A rare pancreatic pseudoaneurysm in patient with acute pancreatitis and multiple myeloma.

The authors report the case of a 78-year old patient affected by multiple myeloma who develops acute pancreatitis and pseudoaneurysmal dilatation of the inferior pancreaticoduodenal artery causing erosion of the second portion of the duodenal wall and hematemesis. The authors focus first on the supposed etiological relationship between multiple myeloma and acute pancreatitis, and they assume that the therapeutic treatment for the bone marrow disease (bortezomib) may have triggered the pancreatic inflammatory response. They then analyze the pathogenesis of the vascular complication which seems to be related to the lytic action of pancreatic enzymes on the vessel wall which results in the formation of a pseudoaneurysm first and a pseudocyst then. The vascular complication was diagnosed by computed tomography (CT) thus avoiding selective angiography which was considered too invasive for the patient. The careful and conservative treatment of the complication has allowed for full healing of the cephalopancreatic region, in addition to avoiding surgery or embolization treatment of the pseudoaneurysm which is accompanied by a mortality rate as high as 50%.

Incidental rectal carcinoid discovered after stapled hemorrhoidopexy: importance of histopathologic examination.

AIM: Haemorrhoids are the most common surgically-treated gastrointestinal disorder. Complications of this surgery are generally non-neoplastic. Because rectal tumours usually present demonstratively during endoscopic examination, it is perhaps tempting to omit histopathologic examination after haemorrhoidectomy, especially in younger patients. METHODS: The AA present a case of an early rectal carcinoid discovered after surgical treatment of haemorrhoids in a 27 years old man as an example of why it is essential to send all such specimens in the pathologist. RESULTS: The detection of early lesions permits the adequate follow-up necessary to preclude more extensive surgery and eventually to prevent recurrence of tumour. CONCLUSION: All tissue resected by haemorrhoidopexy must be sent to the pathology laboratory to protect the life and health of the patient .

Lamellar carbon-aluminosilicate nanocomposites with macroscopic orientation.

Novel preparative approaches towards lamellar nanocomposites of carbon and inorganic materials are relevant for a broad range of technological applications. Here, we describe how to utilize the co-assembly of a liquid-crystalline hexaphenylene amphiphile and an aluminosilicate precursor to prepare carbon-aluminosilicate nanocomposites with controlled lamellar orientation and macroscopic order. To this end, the shear-induced alignment of a precursor phase of the two components resulted in thin films comprising lamellae with periodicities on the order of the molecular length scale, an "edge-on" orientation relative to the substrate and parallel to the shearing direction with order on the centimeter length scale. The lamellar structure, orientation, and macroscopic alignment were preserved in the subsequent pyrolysis that yielded the corresponding carbon-aluminosilicate nanocomposites.

Thyroid surgery without cut and tie: the use of Ligasure for total thyroidectomy.

Total thyroidectomy is the surgical preferred procedure for the treatment of benign and malignant disease. The purpose of this research was to evaluate total thyroidectomy operation by Ligasure in comparison with total thyroidectomy by the traditional technique that uses clamp and tie. We evaluated 256 patients. In 144 patients (56%), we used Ligasure without tie for total thyroidectomy; in the remaining 112 patients (44%), we used clamp and tie. The middle values of the variables examined were inferior (P < 0.0005) in the Ligasure group compared with the clamp and tie group. Only the middle value of operating room costs was higher in the first group than in the second, balanced by a decreased hospital stay of two days. Ligasure can be safely used for total thyroidectomy, because there is a meaningful difference in the distribution of variance between the two groups. There are decreasing risks of parathyroid gland and laryngeal nerve injury in the Ligasure group.

[Intestinal obstruction from undiagnosed rectal and ileal endometriosis. Two clinical cases and review of the most recent literature]. / Sub-occlusione intestinale da insospettata endometriosi rettale ed ileale. Due casi clinici e revisione della più recente letteratura.

Deep endometriosis is a subserosal growth (for more than 5 mm) of funzional endometrial tissue outside the uterine cavity. Authors report two clinical cases of intestinal endometriosis localized in the anterior wall of the rectum and in the last ileal loop. Both cases were characterized by sub-occlusive symptoms, diagnosis performed by laparoscopy and surgical resection. Authors focus the various pathogenetic theories and dwell itself on the symptomatology often characterized by nonspecific abdominal symptoms such as chronic abdominal pain, sometimes in relation to the menstrual cycle, and intestinal disorders. If rectal bleeding is rare, more frequent are dysmenorrhea, dyspareunia and infertility may occur in up to 50% of patients. The diagnosis of intestinal endometriosis is very difficult and can be made by radiological methods (CT or MRI) or by endoscopic ultrasound only for the rectal localization but nowadays often the diagnosis is due to laparoscopic techniques. In the absence of guidelines the surgical therapy is not well defined. When is not necessary surgical emergency, according to the depth of endometriotic infiltration, elective surgery includes several surgical techniques both conservative and extensive such as segmental intestinal resection with hysterectomy and ovariectomy. In the most recent literature, finally, are reported over 50% of pregnancies after surgery

Nanoparticles as suitable messengers for molecular communication.

Molecular communication (MoCo) is a new paradigm of bio-inspired communication in which the transport of information occurs through information particles instead of electromagnetic waves. Herein, the enormous potential of nanoparticles in this field is highlighted. The MoCo concept has been extensively modelled both theoretically and computationally within the scientific community, mainly in the field of engineering. We collected the most relevant findings about the implementation of prototypal MoCo platforms by exploiting nanoparticles as informative nanomessengers and herein the theoretical and computational modelling used to design MoCo systems is presented.

Fluorescent nanoparticle-based Internet of things.

A prototypal molecular Internet of things (IoT) network is reported. Starting from the design of the communication architecture, we have theoretically simulated molecular messenger information exchange by means of fluid-based advection. The objective was to determine the key experimental parameters affecting information storage and transfer efficiency. The first working molecular-IoT prototype, based on a chemical communication network, was then developed. Its selectivity was ensured by employing as many different chemical messengers as networked devices; thus three different carbon nanoparticles, characterized by different fluorescence wavelengths, were employed to ensure an effective communication between three networked actuators.