Detection and imaging of quorum sensing in Pseudomonas aeruginosa biofilm communities by surface-enhanced resonance Raman scattering.

Most bacteria in nature exist as biofilms, which support intercellular signalling processes such as quorum sensing (QS), a cell-to-cell communication mechanism that allows bacteria to monitor and respond to cell density and changes in the environment. As QS and biofilms are involved in the ability of bacteria to cause disease, there is a need for the development of methods for the non-invasive analysis of QS in natural bacterial populations. Here, by using surface-enhanced resonance Raman scattering spectroscopy, we report rationally designed nanostructured plasmonic substrates for the in situ, label-free detection of a QS signalling metabolite in growing Pseudomonas aeruginosa biofilms and microcolonies. The in situ, non-invasive plasmonic imaging of QS in biofilms provides a powerful analytical approach for studying intercellular communication on the basis of secreted molecules as signals.

Pen-on-paper approach toward the design of universal surface enhanced Raman scattering substrates.

The translation of a technology from the laboratory into the real world should meet the demand of economic viability and operational simplicity. Inspired by recent advances in conductive ink pens for electronic devices on paper, we present a "pen-on-paper" approach for making surface enhanced Raman scattering (SERS) substrates. Through this approach, no professional training is required to create SERS arrays on paper using an ordinary fountain pen filled with plasmonic inks comprising metal nanoparticles of arbitrary shape and size. We demonstrate the use of plasmonic inks made of gold nanospheres, silver nanospheres and gold nanorods, to write SERS arrays that can be used with various excitation wavelengths. The strong SERS activity of these features allowed us to reach detection limits down to 10 attomoles of dye molecules in a sample volume of 10 µL, depending on the excitation wavelength, dye molecule and type of nanoparticles. Furthermore, such simple substrates were applied to pesticide detection down to 20 ppb. This universal approach offers portable, cost effective fabrication of efficient SERS substrates at the point of care. This approach should bring SERS closer to the real world through ink cartridges to be fixed to a pen to create plasmonic sensors at will.

No adjustment vs. adjustment formula as input weight for propofol target-controlled infusion in morbidly obese patients.

BACKGROUND AND OBJECTIVE: The purpose of this prospective, randomized, double-blind study was to determine the predictive performance of target-controlled infusions of propofol in morbidly obese patients using the 'Marsh' pharmacokinetic parameter set. METHODS: Twenty-four patients (ASA II or III, age 25-62 years, BMI 35.5-61.7) were randomly allocated to receive propofol target-controlled infusion based on a weight adjustment formula (group adjusted) or without adjustment [group total body weight (TBW)]. Anaesthesia was induced by a propofol-targeted concentration of 6 microg ml that was subsequently adapted to maintain stable bispectral index values ranging between 40 and 50. Arterial blood samples were collected before the start of the infusion and every 15 min thereafter to determine the predictive performances. RESULTS: There were no statistically significant differences between the groups with regard to performance errors, divergence and wobble. Results are presented as median (interquartiles). Median performance error and median absolute performance error were -31.7 (-35.9, -19.4) and 31.7% (20.2, 35.9) for group adjusted and -16.3 (-26.3, 2.2) and 20.6% (14.8, 26.9) for group TBW, respectively. Wobble median value was 7.4% (3.8, 8.4) for group adjusted and 8.2% (7.0, 9.6) for group TBW. As for wobble and divergence, no statistically significant differences were found between groups. CONCLUSION: Weight adjustment causes a clinically unacceptable performance bias, which is not corrected when TBW is used as an input to the 'Marsh' model. It is, therefore, advisable to administer propofol to morbidly obese patients by titration to targeted processed-EEG values.

Surface Functionalization of Grown-on-Tip ZnO Nanopyramids: From Fabrication to Light-Triggered Applications.

We report on a combined chemical vapor deposition (CVD)/radio frequency (RF) sputtering synthetic strategy for the controlled surface modification of ZnO nanostructures by Ti-containing species. Specifically, the proposed approach consists in the CVD of grown-on-tip ZnO nanopyramids, followed by titanium RF sputtering under mild conditions. The results obtained by a thorough characterization demonstrate the successful ZnO surface functionalization with dispersed Ti-containing species in low amounts. This phenomenon, in turn, yields a remarkable enhancement of photoactivated superhydrophilic behavior, self-cleaning ability, and photocatalytic performances in comparison to bare ZnO. The reasons accounting for such an improvement are unravelled by a multitechnique analysis, elucidating the interplay between material chemico-physical properties and the corresponding functional behavior. Overall, the proposed strategy stands as an amenable tool for the mastering of semiconductor-based functional nanoarchitectures through ad hoc engineering of the system surface.

Exciton Fine Structure and Lattice Dynamics in InP/ZnSe Core/Shell Quantum Dots.

Nanocrystalline InP quantum dots (QDs) hold promise for heavy-metal-free optoelectronic applications due to their bright and size-tunable emission in the visible range. Photochemical stability and high photoluminescence (PL) quantum yield are obtained by a diversity of epitaxial shells around the InP core. To understand and optimize the emission line shapes, the exciton fine structure of InP core/shell QD systems needs be investigated. Here, we study the exciton fine structure of InP/ZnSe core/shell QDs with core diameters ranging from 2.9 to 3.6 nm (PL peak from 2.3 to 1.95 eV at 4 K). PL decay measurements as a function of temperature in the 10 mK to 300 K range show that the lowest exciton fine structure state is a dark state, from which radiative recombination is assisted by coupling to confined acoustic phonons with energies ranging from 4 to 7 meV, depending on the core diameter. Circularly polarized fluorescence line-narrowing (FLN) spectroscopy at 4 K under high magnetic fields (up to 30 T) demonstrates that radiative recombination from the dark F = ±2 state involves acoustic and optical phonons, from both the InP core and the ZnSe shell. Our data indicate that the highest intensity FLN peak is an acoustic phonon replica rather than a zero-phonon line, implying that the energy separation observed between the F = ±1 state and the highest intensity peak in the FLN spectra (6 to 16 meV, depending on the InP core size) is larger than the splitting between the dark and bright fine structure exciton states.

Prospective Comparison and Quality of Life for Single-Incision and Conventional Laparoscopic Sleeve Gastrectomy in a Series of Morbidly Obese Patients.

BACKGROUND: Laparoscopic sleeve gastrectomy has gained a wide acceptance in the surgical community with an increasing popularity in the field of bariatric surgery. Simultaneously more surgeons have become acquainted with the single port techniques and sleeve gastrectomy has been regarded as an ideal field of application. Literature is scarce about operative and clinical outcomes of single port sleeve gastrectomy compared to conventional laparoscopy. The primary purpose of the study was to compare operative outcomes in the two study groups. Assessment and comparison of functional outcomes in terms of quality of life between groups was also performed. METHODS: Prospective data on 130 consecutive patients who underwent randomized SI or CL sleeve gastrectomy were collected between January 2009 to December 2014. Preoperative parameters, outcomes, post-operative functional results and quality of life, according to the short-form SF-36 questionnaire, were evaluated and compared between groups. RESULTS: 65 patients underwent conventional laparoscopic (CL) and 65 single incision (SI) sleeve gastrectomy. Operative time, post-operative pain, in-hospital stay, and complications were similar in the two groups. No difference emerged with respect to passage of flatus and resumption of oral intake (p = NS). Cosmetic results were excellent in SI patients with higher satisfaction rates. Post-operative quality of life was significant higher compared to baseline (p < 0.05), and comparable between the two procedures. CONCLUSIONS: Single incision sleeve gastrectomy is safe, effective and comparable to the conventional laparoscopic technique in terms of outcomes. Post-operative quality of life is comparable between the two procedures.

Vertical Gastric Bypass with Fundectomy: Feasibility and 2-Year Follow-Up in a Series of Morbidly Obese Patients.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is the gold standard procedure for morbid obesity and its results are well known and largely discussed. The major limitation of the procedure is the difficult exploration of the excluded gastric pouch and duodenum. The vertical gastric bypass with fundectomy was recently introduced in attempt to overcome these limitations. To date, its effectiveness is debated and outcomes still unclear. The purposes of this study were to describe the vertical gastric bypass with fundectomy and to analyse its outcomes in term of weight loss, complications, and comorbid resolutions. MATERIAL AND METHODS: Since January 2012 to July 2014, 30 consecutive patients were enrolled and prospectively followed for a 24-month period. All patients underwent the vertical gastric bypass with fundectomy. Follow-up visits were scheduled at 7 days, 1, 6, 12, and 24 months, or whenever necessary. RESULTS: Overall, 24 women and six men were enrolled in the study. Mean preoperative BMI was 38.2 ± 8.5 kg/m2. No intraoperative complications were reported. Postoperative overall complication rate was 10%. Compliance to the 24-month follow-up was 100%. Mean BMI and excess weight loss (EWL%) were significantly lower compared to baseline (p < 0.05). Comorbid improvement or resolution was recorded in the 80% of the patients. CONCLUSIONS: Vertical gastric bypass with fundectomy is feasible and effective with similar results in terms of weight loss, complications, and comorbid improving compared to the classic RYGB. Complete evaluation of the gastric anatomy and easy access to the main duodenal papilla are unquestionable advantages.

Disentangling the effect of seed size and crystal habit on gold nanoparticle seeded growth.

Oxidative etching was used to produce gold seeds of different sizes and crystal habits. Following detailed characterization, the seeds were grown under different conditions. Our results bring new insights toward understanding the effect of size and crystallinity on the growth of anisotropic particles, whilst identifying guidelines for the optimisation of new synthetic protocols of predesigned seeds.

Splenic rupture following colonoscopy: Case report and literature review.

INTRODUCTION: Colonoscopy is a safe and routinely performed diagnostic and therapeutic procedure for colorectal diseases. Although bleeding and perforation are most common complications, extra colonic or visceral injuries have been described. Splenic rupture is rare with few cases reported in current literature. PRESENTATION OF CASE: We report the case of a 73-year old man who presented to surgical consultation 50h after colonoscopy. Clinical, laboratory and imaging findings were suggestive for haemoperitoneum. At surgery an almost complete splenic disruption was evident and urgent splenectomy was performed. DISCUSSION: Splenic injury following colonoscopy is exceptional, probably related to instrumental looping with excessive traction on the splenocolic ligament. In patients with an early presentation a sudden onset of symptoms is the rule. By contrast a delayed presentation (>48h) is nonspecific and subtle with arduous diagnosis. CONCLUSION: Awareness of this potential complication, high level of suspicion and prompt treatment are at the basis of better outcomes in such patients.

Subcapsular hepatic haematoma of the right lobe following endoscopic retrograde cholangiopancreatography: Case report and literature review.

Sub capsular hepatic haematoma is a rare complication after endoscopic retrograde cholangiopancreatography (ERCP). Exact pathological mechanism is still unclear and few reports are nowadays available in literature. We report the case of a 58-year-old woman with recurrent episodes of upper abdominal pain, nausea and vomiting. On the basis of laboratory exams, abdomen ultrasound and magnetic resonance imaging she was diagnosed with a common bile duct stone. Endoscopic biliary sphincterotomy was performed. On the following day the patient complaint severe abdominal pain with rebound and hemodynamic instability. A computed tomography scan reveal a 14 cm × 6 cm × 19 cm sub-capsular hepatic haematoma on the right lobe that was successfully managed via percutaneous embolization. Sub capsular liver haematoma is a rare life threatening complication after ERCP that should be managed according to patients' haemodynamic and clinic.

Multifunctional self-assembled composite colloids and their application to SERS detection.

We present a simple method for the co-encapsulation of gold nanostars and iron-oxide nanoparticles into hybrid colloidal composites that are highly responsive to both light and external magnetic fields. Self-assembly was driven by hydrophobic interactions between polystyrene capped gold nanostars and iron oxide nanocrystals stabilized with oleic acid, upon addition of water. A block copolymer was then used to encapsulate the resulting spherical colloidal particle clusters, which thereby became hydrophilic. Electron microscopy analysis unequivocally shows that each composite particle comprises a single Au nanostar surrounded by a few hundreds of iron oxide nanocrystals. We demonstrate that this hybrid colloidal system can be used as an efficient substrate for surface enhanced Raman scattering, using common dyes as model molecular probes. The co-encapsulation of iron oxide nanoparticles renders the system magnetically responsive, so that application of an external magnetic field leads to particle accumulation and limits of detection are in the nM range.

Cystic liver metastases from lung adenocarcinoma: a case report.

Cystic hepatic metastases arising from lung cancer are rare. We herein describe a case of a 71-year-old women admitted to our hospital for abdominal pain 6 months after the resection of a lung adenocarcinoma. Two cystic lesions of the liver were discovered at abdominal ultrasonography and computerized tomography scan. An ERCP excluded a biliary adenoma or adenocarcinoma, and an ultrasound-guided liver biopsy was negative for malignant cells. For persistence of symptoms and lack of a diagnosis, the patient underwent an exploratory laparotomy, a surgical biopsy with a diagnosis of adenocarcinoma, and a consequent right hepatectomy. After 2 years of follow-up, the patient is well and disease free. Although cystic liver metastasis are rare and a differential diagnosis difficult, the malignant nature should always be considered in the differential diagnosis of hepatic cysts to offer the patient the best treatment.

Surgical treatment of hydatid disease of the liver. An experience from outside the endemic area.

Hydatid disease is quite rare in European countries outside the endemic areas. It occurs most frequently in the liver and lungs. Surgery remains the main treatment modality for hydatid disease of the liver. There is still considerable debate as to whether the best approach is conservative surgery or radical surgery in which the cyst is totally removed including the pericyst by total pericystectomy or partial hepatectomy. We report the results of our 15-year experience with this type of surgery. A series of 35 consecutive patients operated on for hydatid disease of the liver from January 1985 to December 2000 was analysed (18 women and 17 men with a mean age of 47.7 years). The most common complaints were pain (59%), hepatomegaly and intra-abdominal masses (37%). The cysts were single in 23 patients and multiple in 12, and were found in the right lobe in 21 cases (59%), in the left lobe in 9 cases (26%), and in both lobes in 5 (15%). In one patient (2.8%), concomitant extrahepatic (splenic) disease was present. The diameter of the cysts ranged from 3.5 to 20 cm (mean value: 9.5 cm). Patients were subdivided according to the kind of surgery (radical versus conservative) and period of operation (group 1: 1985-1992; group 2: 1993-2000). With the increase in surgical skills and the advent of new techniques, radical surgery (12 cystoperistectomies, 3 left lobectomies and 3 segmentectomies) came to be performed more frequently than conservative surgery in the second period (18/20 in group 2 versus in 7/15 group 1) with low complication rates, a 3.7% mortality rate and similar operative time (175 min versus 145 min) and hospital stay (16.8 days versus 19.2 days) as compared to the conservative approach. The policy of applying radical surgery whenever feasible can be implemented with acceptable morbidity and near zero mortality. Radical surgery, however, needs to be applied judiciously, and there is still an important role for conservative surgery.

Gold Nanowire Forests for SERS Detection.

Simple wet chemistry has been applied to control the vertical growth of gold nanowires on a glass substrate. As a consequence, the longitudinal localized surface plasmon band position can be tuned from 656 to 1477 nm in a few minutes by simply controlling the growth rate and time. This allowed us to select the optimum conditions for maximum electromagnetic enhancement and performance in surface enhanced Raman scattering (SERS) detection. SERS measurements confirmed the uniform and reproducible distribution of the nanowires on the substrate, with the subsequent high reproducibility of hot spot formation. Detection of malachite green in water and of 1-naphthalenethiol from the gas phase are demonstrated as proof-of-concept applications of these three-dimensional SERS substrates.

Roux-en-Y reconstruction at greater curvature in biliopancreatic diversion: effects on early postoperative functional recovery.

Delayed gastric emptying after distal gastrectomy and reconstruction of alimentary tract with a gastroenteric anastomosis can significantly influence early and late postoperative course and the length of hospital stay. The purpose of this study was to compare the effect on postoperative functional recovery of two different Roux-en-Y reconstructions: at the gastric greater curvature and at the transected gastric staple line in the Scopinaro's biliopancreatic diversion. We conducted comparative study; 80 patients were enrolled and divided in two groups: group A (RY-GC) and group B (RY-SL) with 40 patients in each group. We compared the early postoperative functional recovery for both groups measuring four parameters: gastric stasis indicated with the volume of the gastric fluid collected per 24 h, day of removal of the nasogastric tube, day of starting the oral intake, and day of hospital discharge. There was statistically significant (p < 0.001) reduction in gastric fluid volume in favor of the RY-GC group starting from the first postoperative day resulting in earlier removal of nasogastric tube with earlier starting of oral feeding than RY-SL group, with no symptoms of stasis required nutrition suspension; while three patients in RY-SL group experienced persistence of nausea and vomiting and needed nutrition suspension for several days. There was statistically significant (p < 0.001) reduction in the hospital stay for RY-GC group. Roux-en-Y reconstruction at the greater curvature ensures a rapid functional recovery with early hospital discharge. The use of stapler devices made this method easier and safer and no complications have arisen with mechanical anastomoses.

Laparoscopic versus open biliopancreatic diversion: a prospective comparative study.

BACKGROUND: Bariatric surgery is playing an increasingly important role in our society. The surgical approach should be chosen in consistent with the patients' problem. The purpose of this study was to compare surgical outcomes in patients who underwent laparoscopic Scopinaro's biliopancreatic diversion (BPD) versus open BPD in our institute experience. METHODS: Eighty patients were enrolled and divided in two groups: laparoscopic group (VL) and open group (OP), with 40 patients in each group during two calendar years 2006-2007. We performed the same technique for both groups using the same staplers for anastomosis, with the same measurements for alimentary and common limbs in both groups. We compared the following variables in the two groups: operative time, intra and early postoperative complications, postoperative pain, consumption of analgesics, recovery of intestinal function, days to removal of NG tube and start of oral intake, hospital stay, and late complication-incisional hernia incidence. RESULTS: We found statistically significant reduction in favor of laparoscopic group regarding reduction in postoperative pain, consumption of analgesics, incidence of incisional hernia, operative time, and hospital stay-with early removal of NG tube and early oral intake. We did not find any statistically significant difference regarding intra, immediate and early postoperative complications and recovery of intestinal functions. CONCLUSIONS: Laparoscopic BPD is a safe technique; has good results without affecting the duration of the intervention; and ensures less postoperative pain with rapid functional recovery, less hospital stay, and drastic reduction of incisional hernia incidence.

Predictive performance of the 'Minto' remifentanil pharmacokinetic parameter set in morbidly obese patients ensuing from a new method for calculating lean body mass.

BACKGROUND AND OBJECTIVES: In a previous article, we showed that the pharmacokinetic set of remifentanil used for target-controlled infusion (TCI) might be biased in obese patients because it incorporates flawed equations for the calculation of lean body mass (LBM), which is a covariate of several pharmacokinetic parameters in this set. The objectives of this study were to determine the predictive performance of the original pharmacokinetic set, which incorporates the James equation for LBM calculation, and to determine the predictive performance of the pharmacokinetic set when a new method to calculate LBM was used (the Janmahasatian equations). METHODS: This was an observational study with intraoperative observations and no follow-up. Fifteen morbidly obese inpatients scheduled for bariatric surgery were included in the study. The intervention included manually controlled continuous infusion of remifentanil during the surgery and analysis of arterial blood samples to determine the arterial remifentanil concentration, to be compared with concentrations predicted by either the unadjusted or the adjusted pharmacokinetic set. The statistical analysis included parametric and non-parametric tests on continuous variables and determination of the median performance error (MDPE), median absolute performance error (MDAPE), divergence and wobble. RESULTS: The median values (interquartile ranges) of the MDPE, MDAPE, divergence and wobble for the James equations during maintenance were -53.4% (-58.7% to -49.2%), 53.4% (49.0-58.7%), 3.3% (2.9-4.7%) and 1.4% h(-1) (1.1-2.5% h(-1)), respectively. The respective values for the Janmahasatian equations were -18.9% (-24.2% to -10.4%), 20.5% (13.3-24.8%), 2.6% (-0.7% to 4.5%) and 1.9% h(-1) (1.4-3.0% h(-1)). The performance (in terms of the MDPE and MDAPE) of the corrected pharmacokinetic set was better than that of the uncorrected one. The predictive performance of the original pharmacokinetic set is not clinically acceptable. Use of a corrected LBM value in morbidly obese patients corrects this pharmacokinetic set and allows its use in obese patients. The 'fictitious height' can be a valid alternative for use of TCI infusion of remifentanil in morbidly obese patients until commercially available infusion pumps and research software are updated and new LBM equations are implemented in their algorithms.