Cobalt–carbon/silica nanocomposites prepared by pyrolysis of a cobalt 2,2′-bipyridine terephthalate complex for remediation of cationic dyes

Recently, carbon nanostructures have attracted interest because of their unique properties and interesting applications. Here, CoC@SiO₂-850 (3) and CoC@SiO₂-600 (4) cobalt–carbon/silica nanocomposites were prepared by solid-state pyrolysis of anthracene with Co(tph)(2,2′-bipy)·4H₂O (1) complex in the presence of silica at 850 and 600 °C, respectively, where 2,2′-bipy is 2,2′-bipyridine and tph is the terephthalate dianion. Moreover, Co(μ-tph)(2,2′-bipy) (2) was isolated and its X-ray structure indicated that cobalt(ii) has a distorted trigonal prismatic coordination geometry. 2 is a metal–organic framework consisting of one-dimensional zigzag chains within a porous grid network. 3 and 4 consist of cobalt(0)/cobalt oxide nanoparticles with a graphitic shell and carbon nanotubes embedded in the silica matrix. They were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS revealed that the nanocomposites are functionalized with oxygen-containing groups, such as carboxylic acid groups. In addition, the presence of metallic cobalt nanoparticles embedded in graphitized carbon was verified by XRD and TEM. The efficiency of 3 for adsorption of crystal violet (CV) dye was investigated by batch and column experiments. At 25 °C, the Langmuir adsorption capacity of 3 for CV was 214.2 mg g⁻¹ and the fixed-bed column capacity was 36.3 mg g⁻¹. The adsorption data were well fitted by the Freundlich isotherm and pseudo-second-order kinetic model. The adsorption process was spontaneous and endothermic.

A cobalt–carbon@silica nanocomposite was synthesized from a cobalt 2,2′-bipyridine terephthalate complex and its adsorption behavior towards crystal violet dye was tested using batch and column techniques.     

Bi-doping improves the magnetic properties of zinc oxide nanowires

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction. However, due to oxidation, the ferromagnetism induced by defects is unstable. In the present work, the solution process synthesis route was utilized to grow pristine and bismuth-doped, highly crystalline ZnO nanowire (ZnO NW)-based samples. The FE-SEM images showed that the grown ZnO NWs have a preferred orientation along the c-axis in the (001) direction due to the anisotropic crystal nature of ZnO. X-ray photoelectron spectroscopy (XPS) confirmed the presence of Bi, and at a higher doping content, the bismuth oxide phase appeared. The XRD patterns showed the wurtzite crystal structure, and the large intensity of the (002) peak suggests that most of the reflection was from the top hexagonal face of the NWs, and thus, the wires are predominantly aligned along the c-axis. The TEM analysis further confirmed the crystal growth direction along the (001) direction. The UV-Visible absorption and PL measurements also showed a decrease in the bandgap with an increase in doping concentration, which may be associated with the sp–d exchange interaction between the localized d-electrons and band electrons of the Bi ions. Bi-doping tended to increase the PL intensity in the visible region. The magnetic properties measured by SQUID at 4 and 300 K showed ferromagnetic behaviour for both the pristine and Bi-doped samples. However, the saturation magnetization for the Bi-doped samples was higher compared to that of the pristine ZnO samples until the threshold doping value. The obtained results demonstrated that Bi-doping can be used to tune both the optical and magnetic properties of ZnO NWs, hence paving the way for future spintronics and spin-polarized optoelectronics applications.

Room-temperature ferromagnetism in the large and direct bandgap diluted magnetic semiconductor zinc oxide (ZnO) is attributed to the intrinsic defects and p-orbital–p-orbital (p–p) coupling interaction.     

Anesthetic management of an infant with Joubert syndrome for cardiac surgery

The anesthetic implications of Joubert syndrome in an infant who required cardiac surgery using cardiopulmonary bypass (CPB) is presented. Children with Joubert syndrome present with central apnea due to malformations in the midbrain and cerebellum. These patients have a marked sensitivity to opioids. The use of dexmedetomidine along with remifentanil was effective in this case.     

Two-Stage Arthroplasty for Prosthetic Joint Infection : A Systematic Review of Acute Kidney Injury,Systemic Toxicity and Infection Control

Periprosthetic infections of hip and knee joints are now treated by two-stage revision arthroplasty with an infection control rate of 91%. The present systematic review studied the reported incidence of acute kidney injury (AKI) and infection recurrence from January 1989 to June 2012 to assess the risk–benefit ratio of antibiotic spacer use. Ten observational studies (n = 544 patients) with clinical outcomes showed an average incidence of AKI of 4.8%. The average reported persistence or recurrence rate of infection was 11% during a follow-up period that ranged from 13 to 108 months. The risk–benefit ratio presently favors treatment although there appears to be higher complication rates and incidence of AKI than previously reported. Marked heterogeneity in practice and lack of detail in reporting precluded more robust quantitative synthesis. Clinicians need to be aware of the potential risk of AKI, particularly in high-risk patients; practice patterns for the use of antibiotic spacers need to be standardized.     

Blood Pressure Recordings During Hemodialysis Access Interventions: Implications for Acute Management

A retrospective study evaluating the pattern of blood pressure and its related complications before, during, and after percutaneous hemodialysis interventions was performed in patients presenting with asymptomatic hypertension. Hemodialysis patients undergoing percutaneous interventions including tunneled hemodialysis catheter insertion, percutaneous balloon angioplasty and thrombectomy procedure, and stage II hypertension (systolic blood pressure ≥160 mmHg) were included in this analysis. Blood pressure medications were not used while midazolam and fentanyl were routinely administered. Patients were followed for up to 4 weeks to monitor any complications. The mean blood pressure before, during, and after the procedures were 185 ± 18/96 ± 14, 172 ± 22/92 ± 15, and 153 ± 25/87 ± 14, respectively. There was a statistically significant difference between the blood pressure readings before and after the procedure (before = 185 ± 18/96 ± 14, after = 153 ± 25/87 ± 14; p = 0.001). None of the patients had a stroke, myocardial infarction, or acute pulmonary edema before, during, or after the procedure or during the 4‐week follow‐up period. A significant reduction in blood pressure was observed after the procedure without the administration of any antihypertensive medication. These results suggest that the reduction in blood pressure observed after percutaneous dialysis access interventions (particularly in the presence of midazolam and fentanyl) may make it unnecessary to treat asymptomatic hypertension prior to these procedures.     

Frequency and Intensity of Postoperative Surveillance After Curative Treatment of Pancreatic Cancer: A Cost-Effectiveness Analysis

Background

Few data exist to guide oncologic surveillance following curative treatment of pancreatic cancer. We sought to identify a rational, cost-effective postoperative surveillance strategy.

Methods

We constructed a Markov model to compare the cost-effectiveness of 5 postoperative surveillance strategies. No scheduled surveillance served as the baseline strategy. Clinical evaluation and carbohydrate antigen (CA) 19-9 testing without/with routine computed tomography and chest X-ray at either 6- or 3-month intervals served as the 4 comparison strategies of increasing intensity. We populated the model with symptom, recurrence, treatment, and survival data from patients who had received intensive surveillance after multimodality treatment at our institution between 1998 and 2008. Costs were based on Medicare payments (2011 US dollars).

Results

The baseline strategy of no scheduled surveillance was associated with a postoperative overall survival (OS) of 24.6 months and a cost of $3837/patient. Clinical evaluation and CA 19-9 assay every 6 months until recurrence was associated with a 32.8-month OS and a cost of $7496/patient, with an incremental cost-effectiveness ratio (ICER) of $5364/life-year (LY). Additional routine imaging every 6 months incrementally increased total cost by $3465 without increasing OS. ICERs associated with clinic visits every 3 months without/with routine imaging were $127,680 and $294,696/LY, respectively. Sensitivity analyses changed the strategies’ absolute costs but not the relative ranks of their ICERs.

Conclusions

Increasing the frequency and intensity of postoperative surveillance of patients after curative therapy for pancreatic cancer beyond clinical evaluation and CA 19-9 testing every 6 months increases cost but confers no clinically significant survival benefit.     

Tracheal intubation with size 1 Airtraq in a 3 month old child with occipital meningocele: A novel experience

Meningocele is a neural tube defect where meninges protrude through a skeletal defect. Occipital meningocele compounded with the problems of paediatric airway itself pose challenges to anaesthesiologist in securing and maintaining airway. We present a case report of a 3 month-old-child with occipital meningocele posted for ventriculo-peritoneal shunt for hydrocephalus, who was successfully intubated using a size 1 Airtraq optical laryngoscope.     

Laparoendoscopic single-site surgery for the placement of an adjustable gastric band: a large cohort comparison

BackgroundLaparoendoscopic single-site (LESS) surgery has been shown to be a well-tolerated alternative for the placement of an adjustable gastric band. To date, only small series have suggested that this approach may provide potential clinical benefits over standard multiport laparoscopy. The objective of this study was to compare the outcomes of patients undergoing LESS adjustable gastric banding (LESS-AGB) and a cohort of patients undergoing standard multiport laparoscopic adjustable gastric banding (LAGB).MethodsA total of 206 patients underwent placement of an adjustable gastric band. Of these, 106 patients underwent LESS-AGB and were compared with a demographically similar cohort of 100 patients who underwent standard LAGB. Data collected included operative time, parenteral and oral narcotic consumption, duration of patient controlled analgesia (PCA) device, subjective pain scores using the 0–10 numeric pain intensity scale, and length of stay. Unpaired t test was used for analysis.ResultsCompared with multiport LAGB patients, LESS-AGB patients reported significantly less pain at the first postoperative hour (P = .012), twelfth postoperative hour (P = .017), and twenty-fourth postoperative hour (P = .012), and consumed fewer oral analgesic tablets (P = .012). Operative times were significantly longer in the LESS-AGB group (P = .029). No significant differences were seen in duration of PCA, parenteral narcotic consumption, or length of stay. One LESS-AGB case required conversion to multiport laparoscopy. Complication rates were similar between the 2 groups.ConclusionLESS-AGB is associated with less pain and less oral analgesic consumption than multiport LAGB. Given these clinical advantages and superior cosmetic results, laparoendoscopic single-site surgery may be an attractive alternative approach for patients considering LAGB. (Surg Obes Relat Dis 2013;0;000–00.) © 2013 American Society for Metabolic and Bariatric Surgery. All rights reserved.