Toxicity of Nd2WO6 nanoparticles to the microalga Dunaliella salina: synthesis of nanoparticles and investigation of their impact on microalgae

The presence of nanoparticles in the environment and their impact on existing organisms is one of the main concerns of researchers working in this field. In this research, Nd₂WO₆ nanoparticles were prepared by an ultrasonic procedure for the first time. X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) analyses were applied to identify and prove the purity of these particles. In addition to increasing the reaction rate and efficiency with the help of a radical generation mechanism, ultrasound was able to aid the synthesis of these particles. After confirming nanoparticle formation, the optimal nanoparticles in view of scale and morphology were selected by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Optimal particles at three concentrations (25, 50, and 100 ppm) were mixed into the algae growth medium to investigate the effects of the nanoparticles on Dunaliella salina growth. Biological parameters, including the number of cells, biomass, specific growth rate, pigments, and malondialdehyde (MDA), were measured after ten days. Growth parameters showed an increasing trend in concentrations up to 50 ppm; however, at a concentration of 100 ppm, a significant decrease was observed in contrast to the nanoparticles-free treatment. The MDA content showed a linear relationship with enhanced concentration of the nanoparticles. The examination of biological parameters showed that the algae response to stress was dependent on the concentration of nanoparticles. The results showed that 50 ppm of nanoparticles are suitable for increasing algae and achieving a suitable growth rate for commercial purposes. However, in higher concentrations, algal growth inhibition occurs, which is of great importance from a biotechnological point of view.

In this work, Nd₂WO₆ nanoparticles were synthesized by the ultrasonic method for the first time. Also, for the first time, the impact of these nanoparticles on the environment was investigated.     

Cobalt-modified palladium nanocatalyst on nitrogen-doped reduced graphene oxide for direct hydrazine fuel cell

Nitrogen-doped reduced graphene oxide-supported palladium–cobalt nanoparticles (PdCo NPs/NrGO NSs) are synthesized and used as a high-performance and low-cost anodic catalyst for direct hydrazine–hydrogen peroxide fuel cells. The SEM and TEM images of PdCo NPs/NrGO NSs show the uniform metal nanoparticle distribution on the NrGO NSs. The reduction of the oxygen functional groups and the doping of the nitrogen atoms in the GO framework are confirmed by FT-IR and XRD spectroscopic studies. The Pd catalysts modified by Co exhibit a higher catalytic activity, lower onset potential, better durability, and lower impedance values than unmodified Pd catalysts for the electro-oxidation of hydrazine. The kinetic studies show a first-order reaction with an activation energy of 12.51 kJ mol⁻¹. A direct hydrazine–hydrogen peroxide fuel cell with PdCo NPs/NrGO NSs as anode and Pt/C as cathode provides an open circuit voltage of 1.76 V and a maximum power density of 148.58 mW cm⁻² at 60 °C, indicating that the PdCo NPs/NrGO NSs are an economical, high performance and reliable anode catalyst for the direct hydrazine–hydrogen peroxide fuel cell.

The superior catalytic activity and stability of a novel anodic PdCo NPs/NrGO NSs for HzOR are confirmed by half and signal cell investigations.     

Dynamics of a novel pathogen in an avian host: Mycoplasmal conjunctivitis in house finches

In early 1994, a novel strain of Mycoplasma gallisepticum (MG)--a poultry pathogen with a world-wide distribution--emerged in wild house finches and within 3 years had reached epidemic proportions across their eastern North American range. The ensuing epizootic resulted in a rapid decline of the host population coupled with considerable seasonal fluctuations in prevalence. To understand the dynamics of this disease system, a multi-disciplinary team composed of biologists, veterinarians, microbiologists and mathematical modelers set forth to determine factors driving and influenced by this host-pathogen system. On a broad geographic scale, volunteer observers ("citizen scientists") collected and reported data used for calculating both host abundance and disease prevalence. The scale at which this monitoring initiative was conducted is unprecedented and it has been an invaluable source of data for researchers at the Cornell Laboratory of Ornithology to track the spread and magnitude of disease both spatially and temporally. At a finer scale, localized and intensive field studies provided data used to quantify the effects of disease on host demographic parameters via capture-mark-recapture modeling, effects of host behavior on disease and vice-versa, and the biological and genetic profiles of birds with known phenotypic characteristics. To balance the field-based component of the study, experiments were conducted with finches held in captivity to describe and quantify the effects of experimental infections on hosts in both individual and social settings. The confluence of these various elements of the investigation provided the foundation for construction of a general compartmentalized epidemiological model of the dynamics of the house finch-MG system. This paper serves several purposes including (i) a basic review of the pathogen, host, and epidemic cycle; (ii) an explanation of our research strategy; (iii) a basic review of results from the diverse multi-disciplinary approaches employed; and (iv) pertinent questions relevant to this and other wildlife disease studies that require further investigation.     

A feasible, aesthetic quality evaluation of implant-supported single crowns: an analysis of validity and reliability

Objectives: To test the reliability and validity of six aesthetic parameters and to compare the professional‐ and patient‐reported aesthetic outcomes. Material and methods: Thirty‐four patients with 66 implant‐supported premolar crowns were included. Two prosthodontists and 11 dental students evaluated six aesthetic parameters, the Copenhagen Index Score (CIS): (i) crown morphology score, (ii) crown colour match score, (iii) symmetry/harmony score, (iv) mucosal discolouration score, (v) papilla index score, mesially and (vi) papilla index score, distally. The intra‐ and inter‐observer agreement and the internal consistency were analysed by Cohen's κ and Cronbach's α, respectively. The validity of CIS parameters was tested against the corresponding Visual Analogue Scales (VAS) scores. The Spearman correlation coefficients were used. Six aesthetic Oral Health Impact Profile (OHIP) questions were correlated to the CIS and the overall VAS scores. Results: The intra‐observer agreement was >70% in 2/3 and >50% in all observations. The inter‐observed agreement was >50% in 4/5 of all observations. The mucosal discolouration score had the overall highest observed agreement followed by the papilla index scores. The crown morphology and the symmetry/harmony scores had the overall lowest agreement. The Cronbach α value was over 0.8 for all observers. All CIS scores demonstrated significant (P<0.0001) correlation to the corresponding VAS scores. Low correlation coefficients (CIS/OHIP: r_s<0.36; VAS/OHIP: r_s >?0,24) were found between patient and professional evaluations. Conclusions: The feasibility, reliability and validity of the CIS make the parameters useful for quality control of implant‐supported restorations. The professional‐ and patient‐reported aesthetic outcomes had no significant correlation. To cite this article:
Hosseini M, Gotfredsen K. A feasible, aesthetic quality evaluation of implant‐supported single crowns: an analysis of validity and reliability.
Clin. Oral Impl. Res. 23 , 2012 453–458.
doi: 10.1111/j.1600‐0501.2011.02162.x     

Robot-assisted Radical Cystectomy: Description of an Evolved Approach to Radical Cystectomy

Background

Although open radical cystectomy (ORC) remains the gold standard of care for muscle-invasive bladder cancer, robot-assisted radical cystectomy (RARC) continues to gain wider acceptance. In this article, we focus on the steps of RARC, describing our approach, which has been developed over the past 10 yr. Totally intracorporeal RARC aims to offer the benefits of a complete minimally invasive approach while replicating the oncologic outcomes of open surgery.

Objective

We report our outcomes of a totally intracorporeal RARC procedure, describing step by step our technique and highlighting the variations on this standard template of nerve-sparing and female organ–preserving approaches in men and women.

Design, setting, and participants

Between December 2003 and October 2012, a total of 113 patients (94 male and 19 female) underwent totally intracorporeal RARC.

Surgical procedure

We performed RARC, extended pelvic lymph node dissection, and a totally intracorporeal urinary diversion (UD) in all patients. In the accompanying video, we focus on the standard template for RARC, also describing nerve-sparing and female organ–preserving approaches.

Outcome measurements and statistical analysis

Complications and oncologic outcomes are reported, including overall survival (OS) and cancer-specific survival (CSS) using Kaplan-Meier analysis.

Results and limitations

RARC with intracorporeal UD was performed in 113 patients. Mean age was 64 yr (range: 37–84). Forty-three patients underwent intracorporeal ileal conduit, and 70 had intracorporeal neobladder. On surgical pathology, 48% of patients had ≤pT1 disease, 27% had pT2 disease, 13% had pT3 disease, and 12% had pT4 disease. The mean number of lymph nodes removed was 21 (range: 0–57). Twenty percent of patients had lymph node–positive disease. Positive surgical margins occurred in six cases (5.3%). Median follow-up was 25 mo (range: 3–107). We recorded a total of 70 early complications (0–30 d) in 54 patients (47.8%), with 37 patients (32.7%) having Clavien grade ≥3. Thirty-six late complications (>30 d) were recorded in 30 patients (26.5%), with 20 patients (17.7%) having Clavien grade ≥3. One patient (0.9%) died within 90 days of operation from pulmonary embolism. Using Kaplan-Meier analysis, CSS was 81% at 3 yr and 67% at 5 yr.

Conclusions

Our structured approach to RARC has enabled us to develop this complex service while maintaining patient outcomes and complication rates comparable with ORC series. Our results demonstrate acceptable oncologic outcomes and encouraging long-term CSS rates.     

Oncologic,Functional, and Complications Outcomes of Robot-assisted Radical Cystectomy with Totally Intracorporeal Neobladder Diversion

Background

Robot-assisted radical cystectomy (RARC) with totally intracorporeal neobladder diversion is a complex procedure that has been reported with good outcomes in small series.

Objective

To present complications and oncologic and functional outcomes of this procedure.

Design, setting, and participants

Between 2003 and 2012 in a tertiary referral center, 70 patients were operated on by two experienced robotic surgeons. Data were collected prospectively and reviewed retrospectively.

Intervention

RARC with totally intracorporeal modified Studer ileal neobladder formation.

Outcome measurements and statistical analysis

The overall outcome of RARC with a totally intracorporeal neobladder was presented by assessing (1) surgical margins, (2) recurrence or cancer-specific death at 24 mo, (3) 30-d and 90-d complications graded according to the modified Clavien-Dindo system, (4) daytime and nighttime continence (no or one pad per day) at 6 and 12 mo, and (5) satisfactory sexual activity or potency at 6 mo and 12 mo. Survival rates were estimated by Kaplan-Meier plots.

Results and limitations

Median follow-up of the cohort was 30.3 mo (interquartile range: 12.7–35.6). We recorded negative margins in 69 of 70 patients (98.6%). Clavien 3–5 complications occurred in 22 of 70 patients (31.4%) at 30 d and 13 of 70 (18.6%) at >30 d. At 90 d, the overall complication rate was 58.5%. Clavien <3 and Clavien ≥3 complications were recorded in 15 of 70 patients (21.4%) and 26 of 70 (37.1%), respectively. Kaplan-Meier estimates for recurrence-free, cancer-specific, and overall survival at 24 mo were 80.7%, 88.9%, and 88.9%, respectively. Daytime continence and satisfactory sexual function or potency at 12 mo ranged between 70% and 90% in both men and women. Limitations of this study include its retrospective design, selection bias due to the learning curve phase, and missing data.

Conclusions

In this expert center for RARC, outcomes after RARC with totally intracorporeal neobladder diversion appear satisfactory and in line with contemporary open series.     

Experimental evaluation of ileal patch in delayed primary repair of penetrating colon injuries: An animal study

Primary repair of traumatic colonic perforation is progressively gaining acceptance as the best method of management. However, when delayed, the risk of infection-related complications may increase. Here, we present a new method of repairing colon perforation in the presence of peritonitis. Acute colon injury was simulated in 22 German shepherd dogs. The dogs were randomly divided into two groups of 11 and after 24 hours they were operated on. The perforations were repaired by subserosal suture technique. In the first group (group A), ileal patch was used. In the other group (group B), the colon was closed by debridement and anastomosis. After 6 weeks, the repairs were assessed on the basis of survival, gross and histological assessments. Nine (82%) dogs in group A and six (56%) in group B survived. Ileal patch utilization significantly decreased the mortality rate (p < 0.05). The cause of death in two group A dogs and five group B dogs was peritonitis and intra-abdominal abscess formation. None of the surviving dogs showed evidence of anastomotic leakage or breakdown. Small bowel patch used in primary repair of colon injury in the presence of peritonitis may decrease the risk of postoperative infection-related complications and the mortality rate.