Does the Schatzker III Tibial Plateau Fracture Exist?

Background: The Schatzker classification system for tibial plateau fractures is one of the most commonly used systems. However, there has been controversy if a Schatzker III type fracture truly exists by their original definition. We aimed to correlate the radiographic and CT images of type III fractures, describe the additional propagating fracture patterns and determine if these fractures do exist by their original description. Methods: This multicenter retrospective cohort observational study included patients with tibial plateau fractures across five trauma centers over 9 years were identified. All X-rays and CT scans were assessed. Two independent fellowship trained, Orthopaedic trauma surgeons reviewed all knee X-rays and classified them according to the Schatzker system. The CTs were subsequently reviewed and the fractures were reclassified based on CT findings. Results: 569 Tibial plateau fractures in 566 patients were analyzed. All X-ray classified Schatzker III fractures were reclassified to a Schatzker II type after review of CT scans by both assessors independently as there were always at least two or more fracture lines propagating from the depressed fragment to the lateral cortex in all cases. The interobserver variability as assessed by the kappa correlation coefficient (κ) for X-rays and CT-based classifications were κ = 0.274 and κ = 0.906, respectively. The majority of cases had two lateral cortical breaks (83.8%). In addition, the depression occurred mostly in the anterolateral and posterolateral positions (60.3%) of the lateral tibial plateau. Conclusion: This study did not support the existence of true Schatzker Type III fractures.

Influence of Cr Ion Bombardment on the Growth of Cu Coatings Deposited by Magnetron Sputtering on ABS Substrates.

Cu coatings were deposited on acrylonitrile-butadiene-styrene copolymer (ABS) substrates by DC magnetron sputtering with Cu target. Cr ions generated by arc evaporation were used to bombard the ABS substrates before the Cu coating process. The influences of the Cr ion bombardment on the surface topography and chemical bonds of the ABS substrates and the adhesion of the Cu coatings on the ABS substrate were studied using scanning electron microscopy, Fourier transform infrared spectroscopy, and micro-Scratch Tester as a function of bias voltage and treatment duration. The results show that the Cr ion bombardment causes Cr particles to embed in the surface. The Cr particles can interlock with the Cu coatings and ABS substrate and significantly improve the coating adhesion. In addition, the Cr particles can act as the nucleation sites of the Cu coatings and facilitate the growth of columnar crystals. Increasing the duration of Cr ion bombardment increases the number of Cr particles and, thus, enhances the adhesion. However, the continuous bombardment results in the degeneration of the ABS surface, causing the formation of the coarse columnar structure of the Cu coatings. Increasing the bias voltage can increase the energy of the Cr particles without causing degeneration of the ABS. The Cu coating deposited on the ABS substrate treated by Cr ion with high-bias voltage and short duration shows a dense and smooth growth structure. In contrast, the bombardment of the Cr ions carried out at high-bias voltage induces the formation of an interfacial layer (amorphous carbon-rich phase) in the ABS surface, which decreases the coating adhesion. It is believed that Cu coatings with strong adhesion and dense structures could be acquired on ABS substrates by optimizing the bias voltage and duration of the Cr ion bombardment pre-treatment.

Prevalence of olfactory and taste dysfunction in COVID-19 patients: a community care facility study.

PURPOSE: We aim to study the prevalence of olfactory and taste dysfunction (OTD) in subjects residing in a Community Care Facility (CCF), a center unique to Singapore that is dedicated to isolate foreign workers with COVID-19 infection who have mild disease with minimal or no symptoms. METHODS: This is a cross-sectional study analyzing data prospectively collected from COVID-19-positive subjects who were admitted into a single-center Singapore EXPO CCF from 1st May 2020 to 1st July 2020. The following variables were collected: age, gender, ethnicity, anosmia, ageusia and acute respiratory infection (ARI) symptoms. Symptoms of anosmia and ageusia were self-declared via a mandatory questionnaire administered on admission. RESULTS: A total of 1983 subjects were included. The overall prevalence of anosmia and ageusia is 3.0% and 2.6%, respectively. 58% of anosmic subjects have co-existent ageusia and 72.6% of anosmic subjects have no concurrent sinonasal symptoms. OTD is less likely to present in subjects who are asymptomatic for ARI, compared to those symptomatic for ARI (anosmia: 2.0% versus 4.4% p = 0.002; ageusia: 1.6% versus 4.2% p < 0.001). There is a difference in the prevalence of OTD between the different ethnic groups (Indian, Chinese, Bangladeshi and Others), with Chinese and Bangladeshi reporting a higher prevalence (p < 0.043) CONCLUSION: The true prevalence of OTD in COVID-19-positive subjects may be low with aggressive screening of all subjects, including those asymptomatic for ARI.

Point of Care Portable Spirometry in the Diagnosis and Treatment of Inpatients with Chronic Obstructive Pulmonary Disease.

INTRODUCTION: Spirometry is required to accurately diagnose chronic obstructive pulmonary disease (COPD). Following an acute exacerbation, it is recommended that spirometry be performed after a delay of 4-6 weeks to allow stability and a measure of 'baseline' lung function. However, poor attendance at these appointments can occur, leading to an inability to confirm the diagnosis of COPD or assess the severity of airflow obstruction. Portable spirometry (PS) is a proven surrogate device that may provide a convenient method to address these issues. The purpose of this study was to compare PS values, obtained prior to hospital discharge to laboratory-based spirometry (LS) results undertaken 4 weeks later. METHODS: Thirty-three eligible inpatients with a clinically determined exacerbation of COPD were recruited. Patients underwent PS prior to discharge and LS 4 weeks later. RESULTS: Reliability of PS values at discharge compared with outpatient LS 4 weeks later was excellent (intraclass correlation coefficient > 0.9). The PS confirmed a new diagnosis of COPD at the bedside in 29% of patients and excluded COPD in 6% at both time points. Patients were found to have a similar severity of airflow obstruction on both PS and LS, with clinical stability maintained between visits. The PS and LS may be used interchangeably for earlier diagnosis of COPD. PS at the point of discharge from hospital offers a unique opportunity to diagnose and facilitate COPD management from hospital to primary care.

Fungal Isolates in Peritoneal Fluid Culture Do Not Impact Peri-Operative Outcomes of Peptic Ulcer Perforation.

Background: Fungal isolates from peritoneal fluid sampling in patients with perforated peptic ulcer (PPU) is not uncommon and its management unclear. This study aims to evaluate whether the presence of fungus in peritoneal fluid cultures is a predictor of morbidity and mortality after laparotomy for PPU. Method: This is a single-center retrospective study including adult patients with perforated gastric and duodenal ulcers over a 10-year period (January 2004 to January 2014). Evaluation of predictors contributing to fungal growth was conducted using multiple logistic regression analysis. Operative factors and 30-day mortality and morbidity outcomes were compared against fungal growth using a multivariable generalized linear mixed model analysis. Results: The median age was 58 (interquartile range [IQR] 44-70) years with 110 (20.3%) females. In addition to hypertension and hyperlipidemia, diabetes mellitus (13.5%), ischemic heart disease (2.6%), and heart failure (2.4%) were common. Fungus was cultured from peritoneal fluid in 209 (38.6%) patients. Median American Society of Anesthesiology (ASA) score was 2 (IQR 2-3) and median Mannheim peritonitis index (MPI) score was 15 (IQR 10-20). Free air was detected in 323 (59.6%) patients and 52 (9.6%) patients had gastrectomy. Median length of stay was 7 (IQR 6-11) days. All-cause complications were seen in 53 (9.8%) patients, of whom 37 patients (6.8%) developed intra-abdominal collection, 20 patients (3.7%) had anastomotic leakage, and 12 patients (2.2%) required repeat operation. Thirty-day mortality was seen in 47 (8.7%) patients. Multivariable analysis showed age (median age, 64; IQR 53-74) as a predictor of fungal growth (p < 0.001) but fungal growth not a predictor of adverse peri-operative outcomes. Conclusion: Fungal isolates in peritoneal fluid cultures are more likely to occur in older patients who have PPU. Presence of fungal isolates does not impact peri-operative outcomes.

'Is it okay for me to ... ?' Assessment of recreational activity risk in patients with chronic lung conditions.

BACKGROUND: Recreational activities, including travel, can be associated with risks to health. Assessing and advising on these risks can be an important part of travel planning for a person with a chronic lung condition when they ask, 'Is it okay for me to ...?' OBJECTIVE: This article discusses the respiratory considerations important in the assessment of, and advice for, a proposed activity in a person with a chronic lung condition. DISCUSSION: Patients with chronic lung disease can safely engage in a range of recreational, sporting and other activities. However, there are a number of general factors that should be taken into account, including access to, and the standard of, medical care available and the travel destination and medication availability. Guidelines based on limited evidence and expert opinion are available for some activities, but not all. Simple precautions and a common sense approach guided by knowledge of the particular risks in each setting should ensure a satisfactory outcome for the patient who asks, 'Is it okay for me to ... ?'

Response of poly-phosphate accumulating organisms to free nitrous acid inhibition under anoxic and aerobic conditions.

The response of free nitrous acid (FNA)-adapted poly-phosphate accumulating organisms (PAOs) to FNA inhibition under aerobic and anoxic conditions was studied. Anoxic P-uptake was 1-6 times more sensitive to the inhibition compared to aerobic P-uptake. The aerobic nitrite reduction rate increased with FNA concentration, accompanied by an equivalent decrease in the oxygen uptake rate, suggesting under high FNA concentration conditions, electrons were channeled to nitrite reduction from oxygen reduction. In contrast, the nitrite reduction rate decreased with increased FNA concentration under anoxic conditions. Anaerobic metabolism of PAO under both anoxic and aerobic conditions was observed at high FNA concentrations. Growth of PAOs decreased sharply with FNA concentration and stopped completely at FNA concentration of 10 µg HNO(2)-N/L. This study, for the first time, investigated the function of nitrite/FNA in an aerobic denitrifying phosphate removal process by evaluating electron as well as energy balances, and provides explanation for FNA inhibition mechanisms.

Nitrous oxide emission by denitrifying phosphorus removal culture using polyhydroxyalkanoates as carbon source.

Nitrous oxide (N2O) emission has been reported to be enhanced during denitrification when internally-stored compounds are used as carbon sources. However, negligible N2O emissions have been detected in the few studies where polyhydroxyalkanoates (PHA) were specifically used. This study investigated and compared the potential enhancement of N2O production, based on utilization of an internally-stored polymer and external carbon (acetate) by a denitrifying phosphorus removal culture. Results indicated that at relatively low chemical oxygen demand-to-nitrogen (COD/N) ratios, more nitrite was reduced to N2O in the presence of an external carbon source as compared to an internal carbon source (PHA). At relatively higher COD/N ratios, similar N2O reduction rates were obtained in all cases regardless of the type of carbon source available. N2O reduction rates were, however, generally higher in the presence of an internal carbon source. Results from the study imply that when the presence of an external carbon source is not sufficient to support denitrification, it is likely competitively utilized by different metabolic pathways of denitrifying polyphosphate accumulating organisms (DPAOs) and other ordinary denitrifiers. This study also reveals that the consumption of PHA is potentially the rate-limiting step for N2O reduction during denitrification.

The role of nitrite and free nitrous acid (FNA) in wastewater treatment plants.

Nitrite is known to accumulate in wastewater treatment plants (WWTPs) under certain environmental conditions. The protonated form of nitrite, free nitrous acid (FNA), has been found to cause severe inhibition to numerous bioprocesses at WWTPs. However, this inhibitory effect of FNA may possibly be gainfully exploited, such as repressing nitrite oxidizing bacteria (NOB) growth to achieve N removal via the nitrite shortcut. However, the inhibition threshold of FNA to repress NOB (∼0.02 mg HNO2-N/L) may also inhibit other bioprocesses. This paper reviews the inhibitory effects of FNA on nitrifiers, denitrifiers, anammox bacteria, phosphorus accumulating organisms (PAO), methanogens, and other microorganisms in populations used in WWTPs. The possible inhibition mechanisms of FNA on microorganisms are discussed and compared. It is concluded that a single inhibition mechanism is not sufficient to explain the negative impacts of FNA on microbial metabolisms and that multiple inhibitory effects can be generated from FNA. The review would suggest further research is necessary before the FNA inhibition mechanisms can be more effectively used to optimize WWTP bioprocesses. Perspectives on research directions, how the outcomes may be used to manipulate bioprocesses and the overall implications of FNA on WWTPs are also discussed.

Free nitrous acid (FNA) inhibition on denitrifying poly-phosphate accumulating organisms (DPAOs).

Free nitrous acid (FNA) has been identified to be a ubiquitous inhibitor of a wide range of microorganisms, including bacteria involved in wastewater treatment. The FNA-induced inhibition on the anoxic (nitrite as electron acceptor) metabolism of denitrifying poly-phosphate accumulating organisms (DPAOs) was investigated using sludge from a sequencing batch reactor performing carbon, nitrogen, and phosphorus removal from synthetic wastewater. We found that FNA had a much stronger inhibitory effect on phosphorus (P) uptake and glycogen production than on poly-beta-hydroxyalkanoate degradation and nitrite reduction. The intracellular adenosine triphosphate levels decreased sharply during the FNA incubation, and the decreasing rates were positively correlated with increasing FNA concentrations. The electron transport activity of DPAOs when exposed to FNA displayed a similar trend. Further, at FNA concentrations above 0.044 mg HNO(2)-N/L, the anaerobic metabolism of DPAOs was initiated despite of the presence of nitrite, as evidenced by the release of phosphorus and the consumption of glycogen. DPAO metabolism did not recover completely from FNA inhibition in the subsequent FNA-free environment. The recovery rate depended on the concentration of FNA applied in the previous anoxic period. These results suggest that the inhibitory effects are diverse and may be attributable to different mechanisms operating simultaneously.

Highly thermostable anatase titania-pillared clay for the photocatalytic degradation of airborne styrene.

Airborne styrene is a suspected human carcinogen, and traditional ways of mitigation include the use of adsorption technologies (activated carbon or zeolites) or thermal destruction. These methods presenttheir own shortcomings, i.e., adsorbents need to be regenerated or replaced regularly, and relatively large energy inputs are required in thermal treatment. Photocatalysis offers a potentially sustainable and clean means of controlling such fugitive emissions of styrene in air. The present study demonstrates a new type of well-characterized, highly thermostable titania-pillared clay photocatalysts for airborne styrene decomposition in a custom-designed fluidized-bed photoreactor. This photocatalytic system is found to be capable of destroying up to 87% of 300 ppmV airborne styrene in the presence of ultraviolet (UV) irradiation. The effects of relative humidity (RH: 0 or 20%) are also studied, together with the arising physical structures (in terms of porosity and surface characteristics) of the catalysts when subjected to relatively high calcination temperatures of 1000-1200 degrees C. Such a temperature range may be encountered, e.g., in flue gas emissions (1). It is found that relative humidity levels of 20% retard the degradation efficiencies of airborne styrene when using highly porous catalysts.