Spray-assisted alignment of Layer-by-Layer assembled silver nanowires: a general approach for the preparation of highly anisotropic nano-composite films

The present article focuses on the build-up and the properties of oriented silver nanowire monolayer films and Layer-by-Layer assembled multilayer films. We describe the template-free oriented spray-assisted assembly of silver nanowires at solid/air-interfaces using Grazing Incidence Spraying, a simple and versatile approach that allows the formation of highly oriented thin films with a tunable density and in-plane orientation. Depending on the spraying conditions the nematic order parameter, which describes the angular spread of misaligned nanowires, can be as high as 0.98 (a value of 1.00 corresponding to a perfectly parallel alignment). The combination with the Layer-by-Layer assembly allows building multilayer thin films possessing in-plane anisotropy. In order to demonstrate that the local alignment does not cancel out on the macroscopic scale but leads to direction-dependent properties, we use linearly polarized UV-Vis-NIR spectroscopy to probe the selective excitation of the transverse and longitudinal localized plasmon resonances of the nanowires. The polarization efficiency of the thin films increases strongly with the in-plane density, the degree of orientation, and the number of silver nanowire layers. Multilayer films containing 4 layers of nanowires oriented in the same direction reach a polarization efficiency of up to 97% in the near-infrared region.

Long term continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) in children: Initiation criteria in real life

INTRODUCTION

Long term noninvasive continuous positive airway pressure (CPAP) and noninvasive ventilation (NIV) are increasingly used in children but limited information is available on the criteria and conditions leading to the initiation of these treatments. The aim of the study is to describe the objective overnight respiratory parameters and clinical situations that led to the initiation of CPAP/NIV in a pediatric NIV unit.

MATERIAL AND METHODS

Retrospective analysis of the data of all the children discharged on home CPAP/NIV over a 1 year period.

RESULTS

Seventy-six patients were started on CPAP (n = 64) or NIV (n = 12). CPAP/NIV was initiated because of CPAP/NIV weaning failure (Acute group) in 15 patients. None of these patients had an overnight gas exchange or sleep study before CPAP/NIV initiation. In 18 patients, CPAP/NIV was initiated on abnormal nocturnal gas exchange alone (Subacute group). These patients had a median of three of the following five overnight gas exchange abnormalities: minimal pulse oximetry (SpO2 ) <90%, maximal transcutaneous carbon dioxide (PtcCO2 ) >50 mmHg, time spent with SpO2 <90% or PtcCO2 >50 mmHg ≥2% of recording time, oxygen desaturation index >1.4/hr. In the last 43 patients, CPAP/NIV was initiated after an abnormal sleep study (Chronic group) on a mean of four of the aforementioned criteria and an apnea-hypopnea index >10/hr.

CONCLUSION

In clinical practice, CPAP/NIV was initiated in an acute, subacute and chronic setting with most patients having an association of several abnormal gas exchange or sleep study parameters. Future studies should evaluate the effectiveness and benefits of CPAP/NIV according to the clinical situation and initiation criteria. Pediatr Pulmonol. 2016; 51:968-974. © 2016 Wiley Periodicals, Inc.

The technical approach to laparoscopic colectomy in patients who have undergone prior abdominoplasty

BACKGROUND

For those patients undergoing laparoscopic colorectal surgery who have had prior abdominoplasty, cosmetic outcome is important and the technical considerations for laparoscopy in post-abdominoplasty patients have not been previously addressed. The aim of the present study was to define the technical approach to the post-abdominoplasty patient undergoing laparoscopic colorectal surgery after abdominoplasty.

METHODS

Utilizing the technical approach described, eleven patients underwent laparoscopy after prior abdominoplasty over a 7-year period.

RESULTS

The majority of patients (10/11) felt their laparoscopic colorectal resection had no adverse effect on the aesthetics of their prior abdominoplasty. From a surgeon's standpoint, the only significant challenge was due to the loss of abdominal wall compliance.

CONCLUSIONS

The surgical approach to laparoscopic colectomy in the post-abdominoplasty patient requires careful planning. Cosmetic outcome is a particularly important consideration for this subset of patients, and this should be appreciated by the operating surgeon.

[Life-threatening complication of schizophrenia]

The Wernicke Encephalopathy (WE) as a result of a (sub)acute thiamine deficiency remains, unfortunately, still under-diagnosed, especially among non-alcoholics. It should be considered in each occurrence of delirium as well as in any ocular motor disorder and ataxia, in particular if there is a history of weight loss with or without gastrointestinal symptoms. In cases with suspected WE an immediate intravenous substitution of 3×200 mg/d is recommended.