Light-induced modulation of viscoelastic properties in azobenzene polymers.

Photo-induced isomerization of azobenzene molecules drives mass migrations in azopolymer samples. The resulting macroscopic directional photo-deformation of the material morphology has found many applications in literature, although the fundamental mechanisms behind this mass transfer are still under debate. Hence, it is of paramount importance to find quantitative observables that could drive the community toward a better understanding of this phenomenon. In this regard, azopolymer mechanical properties have been intensively studied, but the lack of a nanoscale technique capable of quantitative viscoelastic measurements has delayed the progress in the field. Here, we use bimodal atomic force microscopy (AFM) as a powerful technique for nanomechanical characterizations of azopolymers. With this multifrequency AFM approach, we map the azopolymer local elasticity and viscosity, with high resolution, after irradiation. We find that, while in the (previously) illuminated region, a general photo-softening is measured; locally, the Young modulus and the viscosity depend upon the inner structuring of the illuminating light spot. We then propose a possible interpretation based on a light-induced expansion plus a local alignment of the polymer chains (directional hole-burning effect), which explains the experimental observations. The possibility to access, in a reliable and quantitative way, both Young modulus and viscosity could trigger new theoretical-numerical investigations on the azopolymer mass migration dynamics since, as we show, both parameters can be considered measurable. Furthermore, our results provide a route for engineering the nanomechanical properties of azopolymers, which could find interesting applications in cell mechanobiology research.

Identification of ultra-thin molecular layers atop monolayer terraces in sub-monolayer organic films with scanning probe microscopy.

The morphology of sub-monolayer sexithiophene films has been investigated in situ and ex situ as a function of the substrate temperature of deposition. In this thickness range, monolayer terraces formed of edge-on molecules, i.e. nearly upright, are typically nucleated. Herein, the terrace height is found to be correlated to both the film morphology and the substrate surface energy. In particular, the presence of a layer of variable thickness with molecules lying face-on or side-on can be identified atop the terraces when the deposition is carried out on inert substrates. This phenomenon can be evidenced thanks to accurate height measurements made with atomic force microscopy and further data obtained with advanced scanning probe microscopy techniques operating in different environments, viz. liquid, air and vacuum. An upward displacement of molecules from the substrate to the top of the terraces is considered to be responsible of this layer formation, whose molecules weakly interact with the underlying terraces.

Moiré Modulation of Van Der Waals Potential in Twisted Hexagonal Boron Nitride.

When a twist angle is applied between two layered materials (LMs), the registry of the layers and the associated change in their functional properties are spatially modulated, and a moiré superlattice arises. Several works explored the optical, electric, and electromechanical moiré-dependent properties of such twisted LMs but, to the best of our knowledge, no direct visualization and quantification of van der Waals (vdW) interlayer interactions has been presented, so far. Here, we use tapping mode atomic force microscopy phase-imaging to probe the spatial modulation of the vdW potential in twisted hexagonal boron nitride. We find a moiré superlattice in the phase channel only when noncontact (long-range) forces are probed, revealing the modulation of the vdW potential at the sample surface, following AB and BA stacking domains. The creation of scalable electrostatic domains, modulating the vdW potential at the interface with the environment by means of layer twisting, could be used for local adhesion engineering and surface functionalization by affecting the deposition of molecules or nanoparticles.

Visceral adiposity is associated with worse urinary and sexual function recovery after radical prostatectomy: Results from a longitudinal cohort study.

OBJECTIVE: A prospective longitudinal cohort study on the impact of anthropometric measures on the sexual function and continence recovery in patients treated with laparoscopic radical prostatectomy (LRP) is presented. MATERIAL AND METHODS: Anthropometric measures, International Index of Erectile Function (IIEF-5) and International Prostatic Symptoms Score questionnaires, were collected before surgery and at the end of follow-up period. All patients were assigned into the following groups: A) non-obese; B) non-obese with central adiposity; C) obese without central adiposity; D) obese with central adiposity. Urinary and sexual functions were the outcome measures. RESULTS: At the end of follow-up, in 29 patients with visceral adiposity (VA) the median IIEF-5 was 14 (IQR 7-18) while in 49 non-VA patients (62.8%) was 22 (IQR 17-24) (p < 0.001). Twenty-three patients (79.3%) with VA reported complete continence, while 6 (20.7%) used ≥ 2 pads per day. Forty-eight patients (97.9%) without VA reported complete continence. VA was confirmed as a strong independent predictor for worse continence (HR 3.67; 2.75-4.51 CI95% p = 0.003) and sexual function recovery (HR: 4.51; 3.09-5.63 CI95% p < 0.001). CONCLUSION: We truly believe obese with visceral adiposity patients with prostate cancer should receive detailed preoperative counseling before surgery, including higher risk of suboptimal functional outcomes.

Differential Entropy: An Appropriate Analysis to Interpret the Shape Complexity of Self-Similar Organic Islands.

Differential entropy, along with fractal dimension, is herein employed to describe and interpret the shape complexity of self-similar organic islands. The islands are imaged with in situ Atomic Force Microscopy, following, step-by-step, the evolution of their shape while deposition proceeds. The fractal dimension shows a linear correlation with the film thickness, whereas the differential entropy presents an exponential plateau. Plotting differential entropy versus fractal dimension, a linear correlation can be found. This analysis enables one to discern the 6T growth on different surfaces, i.e., native SiOx or 6T layer, and suggests a more comprehensive interpretation of the shape evolution. Changes in fractal dimension reflect rougher variations of the island contour, whereas changes in differential entropy correlates with finer contour details. The computation of differential entropy therefore helps to obtain more physical information on the island shape dependence on the substrate, beyond the standard description obtained with the fractal dimension.

Comparison of GreenLight 180-W XPS laser vaporization versus transurethral resection of the prostate: Outcomes of a single regional center.

BACKGROUND: To evaluate the intermediate perioperative outcomes, rate of complications and functional data after XPS 180-W Greenlight photoselective laser vaporization (PVP) compared with transurethral resection of the prostate (TURP) in a prospective non-randomized single centre study. METHODS: We analyzed a prospectively-maintained database collecting data on 100 patients undergoing surgical treatment of BPH (50 consecutive PVP and 50 consecutive TURP). All complications, recorded and graduated according to the Clavien Dindo system and the clinical, operative, perioperative variables were compared. The functional outcomes, International Prostate Symptom Score (IPSS), max flow rate (Qmax) and Prostate Specific Antigen (PSA), were recorded preoperatively and at 1 year of follow up. RESULTS: Age, prostate volume, use of anticoagulants or antiplatelets, ASA score and operative time were comparable in the two groups. The reduction in the hemoglobin levels (0.46 vs 1.8 g/dL), the catheterization time (1.2 vs 3.2 days), the hospital stay (1.7 vs 3.8 days) and rate of transfused patients (0 vs 8%), were significantly lower for PVP. Transient re-catherization (6 vs 26%) was significantly lower for PVP. The IPSS and Qmax at 1 year showed no significant difference. The rate of repeat TURP/PVP was higher in the TURP group (0 vs 10%). Reduction of PSA, that reflects the major reduction of prostate volume, was statistically greater in PVP group respect TURP group (p = 0.001). CONCLUSIONS: PVP has advantages in terms of perioperative safety and major complications than TURP. Functional outcomes at 1 year of follow-up were comparable.

Bottom Effect in Atomic Force Microscopy Nanomechanics.

In this work, the influence of the rigid substrate on the determination of the sample Young's modulus, the so-called bottom-effect artifact, is demonstrated by an atomic force microscopy force-spectroscopy experiment. The nanomechanical properties of a one-component supported lipid membrane (SLM) exhibiting areas of two different thicknesses are studied: While a standard contact mechanics model (Sneddon) provides two different elastic moduli for these two morphologies, it is shown that Garcia's bottom-effect artifact correction yields a unique value, as expected for an intrinsic material property. Remarkably, it is demonstrated that the ratio between the contact radius (and not only the indentation) and the sample thickness is the key parameter addressing the relevance of the bottom-effect artifact. The experimental results are validated by finite element method simulations providing a solid support to Garcia's theory. The amphiphilic nature of the investigated material is representative of several kinds of lipids, suggesting that the results have far reaching implications for determining the correct Young's modulus of SLMs. The generality of Garcia's bottom-effect artifact correction allows its application to every kind of supported soft film.

Emerging Two-Dimensional Crystallization of Cucurbit[8]uril Complexes: From Supramolecular Polymers to Nanofibers.

The binding of imidazolium salts to cucurbit[8]uril, CB[8], triggers a stepwise self-assembly process with semiflexible polymer chains and crystalline nanostructures as early- and late-stage species, respectively. In such a process, which involves the crystallization of the host-guest complexes, the guest plays a critical role in directing self-assembly toward desirable morphologies. These include platelet-like aggregates and two-dimensional (2D) fibers, which, moreover, exhibit viscoelastic and lyotropic properties. Our observations provide a deeper understanding of the self-assembly of CB[8] complexes, with fundamental implications in the design of functional 2D systems and crystalline materials.

A Multifunctional Interlayer for Solution Processed High Performance Indium Oxide Transistors.

Multiple functionality of tungsten polyoxometalate (POM) has been achieved applying it as interfacial layer for solution processed high performance In2O3 thin film transistors, which results in overall improvement of device performance. This approach not only reduces off-current of the device by more than two orders of magnitude, but also leads to a threshold voltage reduction, as well as significantly enhances the mobility through facilitated charge injection from the electrode to the active layer. Such a mechanism has been elucidated through morphological and spectroscopic studies.

Angstrom-Resolved Metal-Organic Framework-Liquid Interfaces.

Metal-organic frameworks (MOFs) are a class of crystalline materials with a variety of applications in gas storage, catalysis, drug delivery or light harvesting. The optimization of those applications requires the characterization of MOF structure in the relevant environment. Dynamic force microscopy has been applied to follow dynamic processes of metal-organic-framework material. We provide images with spatial and time resolutions, respectively, of angstrom and seconds that show that Ce-RPF-8 surfaces immersed in water and glycerol experience a surface reconstruction process that is characterized by the diffusion of the molecular species along the step edges of the open terraces. The rate of the surface reconstruction process depends on the liquid. In water it happens spontaneously while in glycerol is triggered by applying an external force.

Nanoscale morphological analysis of soft matter aggregates with fractal dimension ranging from 1 to 3.

While the widespread emergence of nanoscience and nanotechnology can be dated back to the early eighties, the last decade has witnessed a true coming of age of this research field, with novel nanomaterials constantly finding their way into marketed products. The performance of nanomaterials being dominated by their nanoscale morphology, their quantitative characterization with respect to a number of properties is often crucial. In this context, those imaging techniques able to resolve nanometer scale details are clearly key players. In particular, atomic force microscopy can yield a fully quantitative tridimensional (3D) topography at the nanoscale. Herein, we will review a set of morphological analysis based on the scaling approach, which give access to important quantitative parameters for describing nanomaterial samples. To generalize the use of such morphological analysis on all D-dimensions (1D, 2D and 3D), the review will focus on specific soft matter aggregates with fractal dimension ranging from just above 1 to just below 3.

Retropubic, Laparoscopic, and Robot-Assisted Radical Prostatectomy: A Comparative Analysis of the Surgical Outcomes in a Single Regional Center.

BACKGROUND: To compare the surgical outcomes of radical prostatectomy (RP) performed via 3 different approaches: retropubic (RRP), laparoscopic-assisted (LRP), and robot-assisted (RARP), in a single non-academic regional center by a single surgeon. MATERIALS AND METHODS: The data of patients undergoing RP from 2005 to 2014 were reviewed. The standard approach changed through the years: RRP (n = 380, years 2005 to 2008), LRP (n = 240, years 2009 to 2011), and RARP (n = 262, years 2012 to 2014). Our analysis included the last consecutive 100 RP for each surgical technique by a single surgeon. A logistic regression model adjusted for pre-and postoperative variables was done to evaluate whether transfusion, conversion, and post-operative complication rates were influenced by the approach. RESULTS: RARP was associated with significantly lower blood loss (400 vs. 600 and 600 ml, respectively), transfusion (6 vs. 21 and 21%, respectively), and shorter hospital stay (6 vs. 7 and 8 days, respectively), compared to LRP and RRP, and a lower conversion rate (1 vs. 12%) compared to LRP. Multivariate analysis adjusted for confounders confirmed that the risk of transfusion and conversion was significantly lower in the RARP group compared to the LRP and RRP groups. The RARP group was also associated with a significantly lower risk of complications compared to the RRP group and with a trend in favor of the RARP group compared to the LRP group. The 1-year continence rate was significantly higher in the RARP group compared to the RRP and LRP groups (80 vs. 72 and 68%, respectively). CONCLUSION: The surgical approach affected the operative outcomes in a regional setting. The advantages of RARP over RRP (complications, transfusion, conversion, hospital stay, 1-year continence) were over LRP as well, with the only exception being complications.

Robotic-assisted partial nephrectomy provides better operative outcomes as compared to the laparoscopic and open approaches: results from a prospective cohort study.

The objective of this is to compare the surgical outcomes of partial nephrectomy (PN), performed via three different approaches: robot-assisted (RAPN), laparoscopic (LPN), and open (OPN), in a single non-academic regional center. The data of patients undergoing PN at our Department from 2005 to 2016 were prospectively collected. A logistic regression model adjusted for preoperative variables (age, tumor size, creatinine and hemoglobin, ASA and Padua scores) was performed to evaluate whether transfusion, conversion, and postoperative complication rate were influenced by the surgical approach. Overall 270 patients underwent PN: analysis included 253 cases (RAPN = 110, LPN = 70, OPN = 73). Preoperative variables did not differ significantly among the three groups. Shorter operative (130 vs 180 and 200') and ischaemia (12 vs 23 and 22') times and longer hospital stay (8 vs 7 and 6 days) were found in the OPN group as compared to LPN and RAPN, respectively. The RAPN group included a higher rate of pT1b (31.8 vs 14.2 and 15%) and malignant histotype (90 vs 82.9 and 68.5%) as compared to LPN and OPN, respectively. Clavien Grade III-IV complications were lower in the RAPN (7.2%) as compared to OPN (12.3%) and LPN (17.1%) groups. Multivariate analysis showed a lower risk for conversion, transfusion and overall complications in the RAPN group versus LPN and OPN. The surgical approach affects the perioperative outcomes in a regional setting. The advantages of RAPN over OPN (lower risk of conversion, transfusion, and overall complications) are extended over LPN as well, although OPN offered faster operative and ischemia times at the expense of greater blood loss and hospital stay.

Early impact of robot-assisted partial nephrectomy on renal function as assessed by renal scintigraphy.

To measure the early impact of robot-assisted partial nephrectomy (RAPN) on renal function as assessed by renal scan (Tc 99m-DTPA), addressing the issue of risk factors for ischemic damage to the kidney. All patients undergoing RAPN for cT1 renal masses between June 2013 and May 2014 were included in this prospective study. Renal function as expressed by glomerular filtration rate (GFR) was assessed by Technetium 99m-diethylenetriaminepentaacetic acid (Tc 99m-DTPA) renal scan preoperatively and postoperatively at 1 month in every patient. A multivariable analysis was used for the determination of independent factors predictive of GFR decrease of the operated kidney. Overall, 32 patients underwent RAPN in the time interval. Median tumor size, blood loss, and ischemia time were 4 cm, 200 mL, and 24 min, respectively. Two grade III complications occurred (postoperative bleeding in the renal fossa, urinoma). The GFR of the operated kidney decreased significantly from 51.7 ± 15.1 mL/min per 1.73 m(2) preoperatively to 40, 12 ± 12.4 mL/min per 1.73 m(2) 1 month postoperatively (p = 0.001) with a decrease of 22.4 %. On multivariable analysis, only tumor size (p = 0.05) was a predictor of GFR decrease of the operated kidney. Robotic-assisted partial nephrectomy had a detectable impact on early renal function in a series of relatively large tumors and prevailing intermediate nephrometric risk. A mean decrease of 22 % of GFR as assessed by renal scan in the operated kidney was found at 1 month postoperatively. In multivariable analysis, tumor size only was a significant predictor of renal function loss.

Unusual case of locally advanced and metastatic paratesticular liposarcoma: a case report and review of the literature.

Liposarcoma accounts for 20% of all sarcomas and is a rare occurrence in the paratesticular region. We present the case of a 66-year-old man with a massive liposarcoma of the right scrotum invading the lower limb and the abdominal wall skin. The case concerns an unusually large and aggressive liposarcoma (25 cm), presenting with multiple lung and nodal metastases. The patient had an unfavourable evolution with rapid progression of metastases, although there were no signs of local disease. In this case, a wide local excision was performed in order to obtain local control of the disease. Even though paratesticular sarcomas might have a more favourable evolution, the association with lung involvement carries an ominous prognosis. Diagnosis of paratesticular sarcoma should be kept in mind in case of irregular necrotic masses in the inguinal and scrotal region.

Apple consumption is related to better sexual quality of life in young women.

INTRODUCTION: Even if some evidence exists of a positive correlation between regular intake of phytoestrogens, polyphenols, antioxidants and women's sexual health, there is not a study addressing the potential correlation between daily apple consumption and women's sexual function. We aim to assess whether there is a tie between daily apple intake and sexual function in a sample of healthy young sexually active Italian women, not complaining of any sexual disorders. MATERIALS AND METHODS: Seven hundred and thirty-one women (mean age 31.9, range 18-43) were enrolled in this cross-sectional study (from September 2011 to April 2012). All participants completed anonymously the Female Sexual Function Index (FSFI) and were asked to report on their amount of daily apple consumption and their eating habits. On the basis of apple consumption all women were split into two groups: Group A--regular daily apple consumption, Group B--no regular apple consumption (<1 apple/day). The main outcome measure was the FSFI questionnaire result. RESULTS: Three hundred and forty-three women reported a regular daily apple intake and were classified in Group A, while 388 were included in Group B. Group A had a significantly higher total (p = 0.001; Cohen's d = 3.39) and lubrication domain (p = 0.001; Cohen's d = 3.02) FSFI scores than participants in Group B. Multivariate analysis demonstrated that daily apple intake must be considered as an independent parameter (p = 0.002) in predicting a better score at questionnaire examination. DISCUSSION: This study suggests a potential relationship between regular daily apple consumption and better sexuality in our young women population.

Operative safety and oncologic outcome of laparoscopic radical nephrectomy for renal cell carcinoma >7 cm: a multicenter study of 222 patients.

OBJECTIVE: To evaluate the safety of laparoscopic radical nephrectomy (LRN) for renal cell carcinoma (RCC) >7 cm, addressing the issue of modality and risk factors for complications and open conversion, and to assess the oncologic outcome. METHODS: The data of 222 patients undergoing LRN for RCC >7 cm prospectively enrolled from 2002 to 2010 at 5 urologic centers were reviewed. Transperitoneal LRN was performed by 5 experienced laparoscopic surgeons. The Clavien-Dindo classification was used to assess complications. Multivariable analysis of factors predictive of conversions was performed. Oncologic outcomes for survival were estimated using the Kaplan-Meier method. RESULTS: Median tumor size was 8.5 cm, operative time was 180 minutes, and blood loss was 280 mL. Forty-two patients (19%) received a blood transfusion. Six (2.7%) patients had grade III-IV complications: 2 with postoperative bleeding requiring abdominal re-exploration and 1 each with adrenal injury, splenic injury, wound diastasis, and respiratory insufficiency. Twelve patients (5.4%) were converted to open surgery. The diameter was 11.9 in converted groups and 8.5 cm in nonconverted groups (P = .001). Multivariable analysis revealed that pathologic stage was the only independent predictor of conversion (P = .002). The 5-year overall (OS), cancer-specific (CSS), and progression-free (PFS) survival was 74%, 78%, and 66%, respectively. The 5-year stage-adjusted CSS was 89% in pT2 and 40% in pT3 patients (P <.0001). Limitations of this study were its retrospective nature and the relatively short follow-up period for oncologic outcome. CONCLUSION: LRN for large RCC is a safe operation. Stage pT3 is a risk factor for open conversion and is associated to significantly lower cancer-specific survival compared with pT2 stage.

Primary aorto-duodenal fistula as a late complication of radiotherapy: report of a case and review of the literature.

Primary aorto-duodenal fistula (PADF) is a rare condition that may result in rapid exsanguination if untreated. PADF due to radiotherapy appears to be extremely rare with only a few cases reported in the medical literature. We report the case of a 61-year-old man who presented with massive gastrointestinal bleeding 25 years after surgery and radiotherapy for seminoma of the testicle and was successfully treated at our institution. We also review the literature on this very uncommon condition. A Medline search was conducted for the period from 1966 to June 2006 to identify case reports of PADF following radiotherapy. Only 7 cases of PADF due to radiotherapy were identified in addition to our own, 4 males and 3 females, aged 40 to 73 years, all treated for various forms of abdominal malignancies. The latency period ranged from 2 weeks to 25 years. None of the aortas were aneurysmatic. One patient died before he could be taken to the operating room. 5 patients underwent surgical repair and 4 survived. 2 patients underwent endovascular treatment but did not survive. PADF may develop up to 25 years after radiotherapy. Diagnosis should be considered when massive upper gastrointestinal bleeding develops in a patient who had previous abdominal radiotherapy, no matter how long before the episode of bleeding. Prompt surgical repair offers a reasonable chance of cure. Endovascular procedures do not appear to be efficacious.

Primary retroperitoneal abscess extending to the calf.

A 77-year-old man with diabetes mellitus presented with a 2-month history of lumbago radiating to the right lower limb as well as high fever spikes. Physical examination revealed a distended abdomen with right lower quadrant tenderness. A computed tomographic scan of the abdomen revealed a large right retroperitoneal cavity containing an air-fluid level that was consistent with a gas-producing abscess. The patient began receiving intravenous antibiotics, but fever and abdominal pain persisted and a large, fluctuating, tender swelling appeared on the medial aspect of his right thigh and right calf. The patient underwent surgical exploration: a right lateral abdominal incision was performed, and the pus collection in retroperitoneal space was completely evacuated. We also made 3 separate incisions on the medial aspect of the right thigh and 1 incision on the upper calf, resulting in the drainage of pus. The patient made a slow but steady recovery.