Performance and onsite regeneration of natural zeolite for ammonium removal in a field-scale non-sewered sanitation system

Natural zeolite clinoptilolite was used as the primary ammonium removal method from the permeate of an anaerobic membrane bioreactor (AnMBR) treating high-strength blackwater generated from a community toilet facility. This zeolite-based nutrient capture system (NCS) was a sub-component of a non-sewered sanitation system (NSSS) called the NEWgenerator and was field tested for 1.5 years at an informal settlement in South Africa. The NCS was operated for three consecutive loading cycles, each lasting 291, 110, and 52 days, respectively. Both blackwater (from toilets) and blackwater with yellow water (from toilets and urinals) were treated during the field trial. Over the three cycles, the NCS was able to remove 80 ± 28%, 64 ± 23%, and 94 ± 11%, respectively, of the influent ammonium. The addition of yellow water caused the rapid exhaustion of zeolite and the observed decrease of ammonium removal during Cycle 2. After Cycles 1 and 2, onsite regeneration was performed to recover the sorption capacity of the spent zeolite. The regenerant was comprised of NaCl under alkaline conditions and was operated as a recycle-batch to reduce the generation of regenerant waste. Modifications to the second regeneration process, including an increase in regenerant contact time from 15 to 30 h, improved the zeolite regeneration efficiency from 76 ± 0.7% to 96 ± 1.0%. The mass of recoverable ammonium in the regenerant was 2.63 kg NH4-N and 3.15 kg NH4-N after Regeneration 1 and 2, respectively. However, the mass of ammonium in the regenerant accounted for only 52.8% and 54.4% of the estimated NH4-N originally sorbed onto the zeolite beds after Cycles 1 and 2, respectively. The use of zeolite clinoptilolite is a feasible method for ammonium removal by NSSS that observe variable nitrogen loading rates, but further research is still needed to recover the nitrogen from the regenerant waste.

Outcomes of Cutaneous Squamous Cell Carcinoma in the Head and Neck Region With Regional Lymph Node Metastasis: A Systematic Review and Meta-analysis

Importance

There is a need to summarize the available evidence and provide quantitative data of the most important prognostic factors for patients with metastatic cutaneous squamous cell carcinoma of the head and neck region with regional lymph node metastasis (McSCCHN).

Objective

To undertake a PRISMA-compliant systematic review and meta-analysis of all published studies on the risk factors for overall survival (OS), locoregional control (LRC), locoregional recurrence (LRR), and disease-specific survival (DSS) for patients with McSCCHN.

Data Sources

PubMed, CINAHL, and Embase were searched from 1946 to August 2018 for English-language articles.

Study Selection

Inclusion criteria were randomized clinical trials or observational studies reporting on at least 10 patients with McSCCHN; studies analyzing 1 defined risk factor; reporting OS, LRC, LRR, or DSS; and clinical follow-up of 1 year of more. For the final analysis we included risk factors that were analyzed for the same outcome in at least 3 studies. Of the 2923 articles screened, 21 articles met the inclusion criteria.

Data Extraction and Synthesis

PRISMA guidelines were used for abstracting the data. Two reviewers independently abstracted the data. Risk of bias was estimated with the Newcastle-Ottawa Scale. Meta-analysis was performed using the random-effects model. All analysis took place between January and October 2018.

Main Outcomes and Measures

The primary end point was OS. Secondary end points included LRC, LRR, and DSS.

Results

A total of 20 observational studies and 1 randomized clinical trial were identified, representing 3534 patients (some reviewed articles reported no demographic characteristics), and were included in the analysis. Significant risk factors associated with OS were immunosuppression (hazard ratio [HR] of death, 2.66; 95% CI, 2.26-3.13), extracapsular spread (HR, 1.90; 95% CI, 1.12-3.23), adjuvant radiotherapy (HR, 0.45; 95% CI, 0.27-0.78), lymph node ratio (HR, 1.91; 95% CI, 1.09-3.35), and advanced age (HR, 1.03; 95% CI, 1.00-1.07). Immunosuppression (HR, 3.82; 95% CI, 2.47-5.92) and adjuvant radiotherapy (HR, 0.52; 95% CI, 0.33-0.84) were also significant risk factors for DSS.

Conclusions and Relevance

Immunosuppressed patients and those with extracapsular extension have poor prognosis. Adjuvant radiotherapy is associated with an improvement in OS. These risk factors will assist with better risk stratification and may also help to inform future clinical trials.

Formation of optical supramolecular structures in a fibre laser by tailoring long-range soliton interactions

Self-assembly of fundamental elements through weak, long-range interactions plays a central role in both supramolecular DNA assembly and bottom-up synthesis of nanostructures. Optical solitons, analogous in many ways to particles, arise from the balance between nonlinearity and dispersion and have been studied in numerous optical systems. Although both short- and long-range interactions between optical solitons have attracted extensive interest for decades, stable soliton supramolecules, with multiple aspects of complexity and flexibility, have thus far escaped experimental observation due to the absence of techniques for enhancing and controlling the long-range inter-soliton forces. Here we report that long-range soliton interactions originating from optoacoustic effects and dispersive-wave radiations can be precisely tailored in a fibre laser cavity, enabling self-assembly of large numbers of optical solitons into highly-ordered supramolecular structures. We demonstrate several features of such optical structures, highlighting their potential applications in optical information storage and ultrafast laser-field manipulation.

Metastatic mammary carcinoma to the orbit masquerading as maxillary sinusitis

INTRODUCTION

We report on a case of isolated metastatic breast cancer to the medial rectus muscle. This entity is exceedingly rare.

CASE

A 44-year-old female with a history of breast cancer presented with unilateral maxillary symptoms and was treated for sinusitis. Over time, she developed ocular pain, diplopia, blurred vision and eventually complete adduction deficit.

RESULTS

T1-weighted magnetic resonance imaging revealed a medial rectus lesion. Biopsy via transnasal transorbital endoscopic approach revealed metastatic mammary carcinoma.

DISCUSSION

Metastatic disease to the orbit should be considered in the differential diagnosis of refractory maxillary sinus pain in patients with a known underlying malignancy.

The usefulness of routine histopathology of bilateral nasal polyps - a systematic review, meta-analysis, and cost evaluation

Background

Controversy regarding the usefulness of routine histopathological examination of bilateral nasal polyps removed during endoscopic sinus surgery to identify occult diagnoses still exists. There is a paucity of high-level evidence in the literature.

Methods

A systematic review and meta-analysis was conducted. Two independent reviewers were used. Pooled proportions and numbers needed to screen were calculated. A cost per life year model was generated based on varying survival benefits and compared to other Canadian screening programs to provide financial context.

Results

Six studies (n = 3772 patients) were included. Of the 3772 patients, 3751 had a pre-operative clinical and post-operative pathological diagnosis of inflammatory nasal polyps. Agreement proportion was 99.44 %. There were 18 unexpected benign and three unexpected malignant diagnoses identified. This translated to a proportion of 0.48 and 0.08 % respectively. Number needed to screen was 210 and 1258 respectively. Pooled proportion for expected findings using a random effect model was 0.99 (95 % CI = 0.99–1). Pooled proportion for unexpected benign findings using a random effect model was 0.00522 (95 % CI = 0.00133–0.01). Pooled proportion for unexpected malignant findings using a random effect model was 0.00107 (95 % CI = 0.000147–0.00283). The cost to pick up one unexpected benign diagnosis was $14557.2. The cost to pick up 1 unexpected malignant diagnosis was $87204.56. Cost per quality life year calculated ranged from 3211.83 to $64677.58 based on varying assumptions on the survival benefits of identifying an unexpected malignancy.

Conclusions

Routine pathological examination in screening for neoplasia may be low yield, however, no compelling evidence was found to cease such practice. Surgeons should exercise individual judgment in requesting routine examination.

Electronic supplementary material

The online version of this article (doi:10.1186/s40463-015-0100-8) contains supplementary material, which is available to authorized users.

Transoral robotic surgery vs. radiotherapy for management of oropharyngeal squamous cell carcinoma - A systematic review of the literature

BACKGROUND

Intensity-modulated radiation therapy (IMRT) with or without concurrent chemotherapy is widely utilized for the treatment of oropharyngeal squamous cell carcinoma (OPSCC). However, due to significant acute and late toxicities there has been increasing interest in minimally invasive surgical approaches, particularly transoral robotic surgery (TORS) in an attempt to preserve patient quality of life while maintaining oncologic outcomes. The aim of this study was to review the current literature in order to compare primary IMRT versus TORS in the management of OPSCC.

METHODS

A MEDLINE search was conducted to identify studies reporting on the outcomes of TORS or IMRT in the treatment of OPSCC. Reference lists were also reviewed for relevant articles. Oncologic, functional, and quality of life data is summarized and discussed.

RESULTS

One hundred-ninety papers were identified through the MEDLINE search. An additional 52 papers were retrieved by hand searching the reference lists. Ultimately, 44 papers were identified that discussed outcomes after IMRT or TORS for OPSCC. No outcomes from randomized trials were identified.

CONCLUSION

No randomized trials comparing TORS versus IMRT to each other were identified. Uncontrolled reports from the current literature suggest comparable oncologic outcomes with TORS compared to IMRT and functional outcomes may be superior. However, the median follow-up was relatively short and the TORS studies included patients with earlier stage OPSCC on average compared to IMRT studies. Prospective, randomized controlled trials and direct, well-matched comparisons are needed to further elucidate the role for TORS in the treatment of oropharyngeal squamous cell carcinoma.

Surgeon-estimated costs of common consumables in otolaryngology

OBJECTIVES/HYPOTHESIS

The current fiscal climate demands increasing emphasis on curbing hospital expenses incurred from surgical procedures. Disposable instruments and consumables play a major role, but the end user (the surgeon) is often unaware of the cost of these materials. The objectives of our study were: 1) to assess knowledge of costs of disposable instruments and consumable products, and 2) to gauge interest in greater access to cost information and its potential to change practice.

STUDY DESIGN

We used a cross-sectional survey study to meet our study's objectives.

METHODS

A paper-based anonymous questionnaire was administered in the Department of Otolaryngology at McGill University and at Western University asking for estimations of costs of 23 commonly used products in the operating room. Our primary outcome measure was accuracy of cost estimations, which were considered accurate if within ± 50% of the true cost at the respective institution.

RESULTS

The average accuracy was 29.9% (standard deviation = 16.7%). There was no significant difference between residents (32.5%, 95% confidence interval [CI]: 10.2%-54.7%) and staff (28.3%, 95% CI: 11.0%-45.6%). Less than 10% of participants were able to accurately estimate the costs of at least half of the disposable products. The majority of participants (82%) felt that greater information would change their use of consumables.

CONCLUSIONS

Surgical residents and staff have a generally poor knowledge of the cost of common consumable products used in the operating room. There is potential for increased awareness of costs to change behavior.

LEVEL OF EVIDENCE

NA.

The utility of routine polyp histopathology after endoscopic sinus surgery

BACKGROUND

Routine histopathological assessment is standard practice for nasal polyp specimens obtained during endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS). Retrospective studies suggest that routine histopathology of nasal polyps shows few unexpected diagnoses that alter patient management. Our objective was to study the use of routine pathological analysis, and its cost to the healthcare system, in a prospective manner.

METHODS

A multicenter prospective assessment was performed from data collected between 2007 and 2013. Only cases of patients undergoing ESS for bilateral CRS were included. We excluded unilateral disease cases, and cases in which diagnoses other than polyps were suspected either preoperatively or intraoperatively. We then compared the preoperative diagnosis with the final histopathology and identified the rate of unexpected pathologies. A cost analysis was performed.

RESULTS

Only 4 of 866 pathological specimens were identified as having a clinically significant unexpected diagnosis. All unexpected pathologies in this series were benign. These 4 cases account for 0.46% of all specimens reviewed. This translates to a number needed to screen of 217 cases of bilateral CRS to discover 1 unexpected pathology. The associated cost for making an unexpected diagnosis was $19,192.73.

CONCLUSION

Routine histopathology of nasal polyps in ESS for bilateral CRS with polyps yields few unexpected and management-altering diagnoses. It carries a significant cost to the healthcare system. In cases of bilateral CRS with no other concerning clinical features, clinicians should exercise judgment in submitting polyp specimens for pathology rather than routinely sending polyps for histopathologic analysis.

Anaerobic biodegradability of Tween surfactants used as a carbon source for the microbial reductive dechlorination of hexachlorobenzene

Three structurally-related, nonionic, polysorbate surfactants (Tween 60, 61, and 65) were used as the sole carbon source to sustain the microbial, sequential reductive dechlorination of hexachlorobenzene (HCB) in a mixed, methanogenic culture derived from a contaminated estuarine sediment. The surfactants were partially degraded and fermented to methane with no measurable accumulation of volatile fatty acids, indicating that methanogenesis was rapid relative to the rates of hydrolysis and acidogenesis. Addition of the methanogenesis inhibitor 2-bromoethanesulfonic acid resulted in acetate accumulation without impact on the sequential dechlorination of HCB. An anaerobic biodegradability assay was performed and the following data were obtained for the Tween 60, 61, and 65, respectively: 53, 62, and 62% COD destruction; 35, 57, and 48% COD to methane conversion; and 38, 38, and 45% COD to acetate conversion. These data suggest that the hydrophobic moiety (stearate) of the surfactants was preferentially degraded, most likely through beta-oxidation, to acetate and ultimately to methane and carbon dioxide. Between 38 and 47% of the initial surfactant COD remained after 46 d incubation, which most likely corresponds to the hydrophilic polyoxyethylene moiety. An anaerobic biodegradation pathway of the Tween surfactants is proposed.

Development of hexachlorobenzene-dechlorinating mixed cultures using polysorbate surfactants as a carbon source

The use of three nonionic polysorbate surfactants--Tween 60, 61 or 65--as the sole carbon source to sustain methanogenesis and dechlorination, as well as the effect of long-term exposure of enriched cultures to these surfactants, was investigated through the development of three sediment-derived cultures. Over a one-year period, the carbon source in these cultures was gradually switched from glucose and methanol to surfactant only, while the surfactant concentration was increased from an initial concentration of 100 mg/L to 400 mg/L. In each feeding cycle, the surfactants were partially degraded and converted to methane. Transition from glucose to Tween surfactants as the electron donor did not affect the rate, extent, and pathway of HCB transformation. These surfactants sustained the reductive dechlorination of HCB even after one year of continuous addition to the enriched cultures. This study demonstrated that reductive dechlorination of HCB sustained by the fermentation of Tween surfactants is feasible. The results support the use of anaerobically degradable Tween surfactants for the biotransformation of polychlorinated organic compounds. In principle, these surfactants could be used to simultaneously increase the bioavailability of subsurface contaminants while serving as the carbon and electron source for microbial reductive dechlorination.