In situ ascending aortic thrombus in a patient with metastatic lung adenocarcinoma and no aortic atherosclerosis or cisplatin exposure: a case report.

BACKGROUND: An ascending aortic thrombus is exceedingly rare. Two instances have been reported in the setting of lung cancer, but only after cisplatin use, which is associated with hypercoagulability. We present the first case of a patient with lung cancer who developed an ascending aortic thrombus without structural risk factors or chemotherapy use. CASE: A 60-year-old white female with significant smoking history presented with several weeks of malaise. A chest computed tomography scan revealed a 2.2-cm right upper lobe mass. As an outpatient, right hilar lymph node immunohistochemistry (IHC) samples via endobronchial ultrasound confirmed thyroid transcription factor-1 adenocarcinoma. After the procedure, the patient endorsed dyspnea and was advised to go to the emergency department. A chest computed tomography angiography identified a new 2.4 × 1.1 × 1.1 cm thrombus within the proximal aortic arch. No pulmonary emboli or intrapulmonary shunts were identified. A hypercoagulable workup was negative. Transthoracic echocardiogram was without left ventricular thrombus, akinesis or hypokinesis, left atrial dilation, or intracardiac shunts. A lower extremity ultrasound was negative for deep vein thrombosis. Given the procedural risk, thrombectomy was deferred. The patient was transitioned to enoxaparin, and a repeat computed tomography for resolution is in process. CONCLUSION: To our knowledge, this is the only case detailing an in situ ascending aortic thrombus in the setting of lung cancer, without structural risk factors, chemotherapy use, or other hypercoagulable comorbidities. Optimal management for an aortic thrombus and malignant disease is less clear. Clinicians should be vigilant for unusual arterial thromboses in patients with high metastatic burden.

Factors influencing the indication of coronary angiography in patients presenting with chest pain unspecified: an analysis of two decades (1994-2014).

Guidelines for cardiac catheterization in patients with non-specific chest pain (NSCP) provide significant room for provider discretion, which has resulted in variability in the utilization of invasive coronary angiograms (CAs) and a high rate of normal angiograms. The overutilization of CAs in patients with NSCP and discharged without a diagnosis of coronary artery disease is an important issue in medical care quality. As a result, we sought to identify patient demographic, socioeconomic, and geographic factors that influenced the performance of a CA in patients with NSCP who were discharged without a diagnosis of coronary artery disease. We intended to establish reference data points for gauging the success of new initiatives for the evaluation of this patient population. In this 20-year retrospective cohort study (1994-2014), we examined 107 796 patients with NSCP from the Myocardial Infarction Data Acquisition System, a large statewide validated database that contains discharge data for all patients with cardiovascular disease admitted to every non-federal hospital in NJ. Patients were partitioned into two groups: those offered a CA (CA group; n = 12 541) and those that were not (No-CA group; n = 95 255). Geographic, demographic, and socioeconomic variables were compared between the two groups using multivariable logistic regression, which determined the predictive value of each categorical variable on the odds of receiving a CA. Whites were more likely than Blacks and other racial counterparts (19.7% vs. 5.6% and 16.5%, respectively; P < .001) to receive a CA. Geographically, patients who received a CA were more likely admitted to a large hospital compared to small- or medium-sized ones (12.5% vs. 8.9% and 9.7%, respectively; P < .05), a primary teaching institution rather than a teaching affiliate or community center (16.1 % vs. 14.3% and 9.1%, respectively; P < .001), and at a non-rural facility compared to a rural one (12.1% vs. 6.5%; P < .001). Lastly from a socioeconomic standpoint, patients with commercial insurance more often received a CA compared to those having Medicare or Medicaid/self-pay (13.7% vs. 9.5% and 6.0%, respectively; P < .001). The utilization of CA in patients with NSCP discharged without a diagnosis of coronary artery disease in NJ during the study period may be explained by differences in geographic, demographic, and socioeconomic factors. Patients with NSCP should be well scrutinized for CA eligibility, and reliable strategies are needed to reduce discretionary medical decisions and improve quality of care.

The power of three: Atrial rate limit power-on-reset - A non-electromagnetic cause of pacemaker-induced extracardiac stimulation.

BACKGROUND: Power-on reset (PoR) is most commonly due to electromagnetic interference. Full PoR results in a switch to an inhibited mode (VVI) pacing and resets pacing outputs to maximal unipolar settings, leading to extracardiac stimulation. METHODS: We present a case of PoR occurrence in the absence of electromagnetic interference, resulting in pectoral stimulation triggered by violation of the atrial rate limit. CONCLUSIONS: It is useful for clinicians to recognizethe occurrence of PoR in the setting of atrial limit violation andthe appropriate management in such circumstances.

Cardiac Computed Tomography Angiography in CAD Risk Stratification and Revascularization Planning.

PURPOSE OF REVIEW: Functional stress testing is frequently used to assess for coronary artery disease (CAD) in symptomatic, stable patients with low to intermediate pretest probability. However, patients with highly vulnerable plaque may have preserved luminal patency and, consequently, a falsely negative stress test. Cardiac computed tomography angiography (CCTA) has emerged at the forefront of primary prevention screening and has excellent agency in ruling out obstructive CAD with high negative predictive value while simultaneously characterizing nonobstructive plaque for high-risk features, which invariably alters risk-stratification and pre-procedural decision making. RECENT FINDINGS: We review the literature detailing the utility of CCTA in its ability to risk-stratify patients with CAD based on calcium scoring as well as high-risk phenotypic features and to qualify the functional significance of stenotic lesions. SUMMARY: Calcium scores ≥ 100 should prompt consideration of statin and aspirin therapy. Spotty calcifications < 3 mm, increased non-calcified plaque > 4 mm3 per mm of the vessel wall, low attenuation < 30 HU soft plaque and necrotic core with a rim of higher attenuation < 130 HU, and a positive remodeling index ratio > 1.1 all confer additive risk for acute plaque rupture when present. Elevations in the perivascular fat attenuation index > -70.1 HU are a strong predictor of all-cause mortality and can further the risk stratification of patients in the setting of a non-to-minimal plaque burden. Lastly, a CT-derived fractional flow reserve (FFRCT) < 0.75 or values from 0.76 to 0.80 in conjunction with additional risk factors is suggestive of flow-limiting disease that would benefit from invasive testing. The wealth of information available through CCTA can allow clinicians to risk-stratify patients at elevated risk for an acute ischemic event and engage in advanced revascularization planning.

New molecular insights for 4H-1,2,4-triazole derivatives as inhibitors of tankyrase and Wnt-signaling antagonist: a molecular dynamics simulation study.

Tankyrase (TNKS) enzymes remained central biotargets to treat Wnt-driven colorectal cancers. The success of Olaparib posited the druggability of PARP family enzymes depending on their role in tumor proliferation. In this work, an MD-simulation-based comparative assessment of the protein-ligand interactions using the best-docked poses of three selected compounds (two of the designed and previously synthesized molecules obtained through molecular docking and one reported TNKS inhibitor) was performed for a 500 ns period. The PDB:ID-7KKP and 3U9H were selected for TNKS1 and TNKS2, respectively. The Molecular Mechanics Generalized Born Surface Area (MM-GBSA) based binding energy data exhibited stronger binding of compound-15 (average values of -102.92 and -104.32 kcal/mol for TNKS1 and TNKS2, respectively) as compared to compound-22 (average values of -82.99 and -85.68 kcal/mol for TNKS1 and TNKS2, respectively) and the reported compound-32 (average values of -81.89 and -74.43 kcal/mol for TNKS1 and TNKS2, respectively). Compound-15 and compound-22 exhibited comparable or superior binding to both receptors forming stable complexes when compared to that of compound-32 upon examining their MD trajectories. The key contributors were hydrophobic stacking and optimum hydrogen bonding allowing these molecules to occupy the adenosine pocket by interfacing D-loop residues. The results of bond distance analysis, radius of gyration, root mean square deviation, root mean square fluctuation, snapshots at different time intervals, LUMO-HUMO energy differences, electrostatic potential calculations, and binding free energy suggested better binding efficiency for compound-15 to TNKS enzymes. The computed physicochemical and ADMET properties of compound-15 were encouraging and could be explored further for drug development.Communicated by Ramaswamy H. Sarma.

Internal Medicine Resident Adherence to Evidence-Based Practices in Management of Diabetes Mellitus.

OBJECTIVE: Diabetic preventative health maintenance involves (1) adherence to guidelines and (2) appropriate documentation. This study evaluates the frequency with which internal medicine (IM) residents met these two outcomes. We also evaluated if there were differences in outcomes between resident classes. METHODS: In this retrospective analysis, 234 diabetic outpatient visits were analyzed. Guidelines were derived from the American Diabetes Association (ADA). The outcomes for each guideline were averaged and stratified by resident class. Averages within and between classes were compared using the student's paired t-test and one-way ANOVA respectively. RESULTS: Classes were most adherent to A1c testing guidelines (PGY-1 96.1%, PGY-2 97.6%, and PGY-3 95.9%). PGY-1 and PGY-2 classes were least adherent to podiatry (27.5% and 17.6% respectively), whereas PGY-3 had equal least adherence rates to podiatry and lifestyle modification guidelines (36.7%). All classes had highest rates in documenting A1c findings (PGY-1 92.2%, PGY-2 97.6%, and PGY-3 85.7%) and lowest rates in documenting relevant podiatry information (PGY-1 5.9%, PGY-2 5.9%, and PGY-3 11.2%). Comparing sequential resident classes, there was a decline in lifestyle counselling and documentation from PGY-1 to PGY-2. From PGY-2 to PGY-3, there was improvement in adherence to statin, podiatry, microalbuminuria, and monofilament guidelines. There was also improvement in documenting statin and monofilament usage, however, A1c reporting declined. CONCLUSION: The findings of the study suggest disproportionate levels of care in diabetes preventative management. Additionally, program directors should take caution in assuming linear improvement with sequential resident classes.

Restrictive versus liberal transfusion in patients with diabetes undergoing cardiac surgery: An open-label, randomized, blinded outcome evaluation trial.

AIM: To characterize the association between diabetes and transfusion and clinical outcomes in cardiac surgery, and to evaluate whether restrictive transfusion thresholds are harmful in these patients. MATERIALS AND METHODS: The multinational, open-label, randomized controlled TRICS-III trial assessed a restrictive transfusion strategy (haemoglobin [Hb] transfusion threshold <75 g/L) compared with a liberal strategy (Hb <95 g/L for operating room or intensive care unit; or <85 g/L for ward) in patients undergoing cardiac surgery on cardiopulmonary bypass with a moderate-to-high risk of death (EuroSCORE ≥6). Diabetes status was collected preoperatively. The primary composite outcome was all-cause death, stroke, myocardial infarction, and new-onset renal failure requiring dialysis at 6 months. Secondary outcomes included components of the composite outcome at 6 months, and transfusion and clinical outcomes at 28 days. RESULTS: Of the 5092 patients analysed, 1396 (27.4%) had diabetes (restrictive, n = 679; liberal, n = 717). Patients with diabetes had more cardiovascular disease than patients without diabetes. Neither the presence of diabetes (OR [95% CI] 1.10 [0.93-1.31]) nor the restrictive strategy increased the risk for the primary composite outcome (diabetes OR [95% CI] 1.04 [0.68-1.59] vs. no diabetes OR 1.02 [0.85-1.22]; Pinteraction  = .92). In patients with versus without diabetes, a restrictive transfusion strategy was more effective at reducing red blood cell transfusion (diabetes OR [95% CI] 0.28 [0.21-0.36]; no diabetes OR [95% CI] 0.40 [0.35-0.47]; Pinteraction  = .04). CONCLUSIONS: The presence of diabetes did not modify the effect of a restrictive transfusion strategy on the primary composite outcome, but improved its efficacy on red cell transfusion. Restrictive transfusion triggers are safe and effective in patients with diabetes undergoing cardiac surgery.

Tankyrase inhibitors as antitumor agents: a patent update (2013 - 2020).

INTRODUCTION: Tankyrase inhibitors gained significant attention as therapeutic targets in oncology because of their potency. Their primary role in inhibiting the Wnt signaling pathway makes them an important class of compounds with the potential to be used as a combination therapy in future treatments of colorectal cancer. AREAS COVERED: This review describes pertinent work in the development of tankyrase inhibitors with a great emphasis on the recently patented TNKS inhibitors published from 2013 to 2020. This article also highlights a couple of promising candidates having tankyrase inhibitory effects and are currently undergoing clinical trials. EXPERT OPINION: Following the successful clinical applications of PARP inhibitors, tankyrase inhibition has gained significant attention in the research community as a target with high therapeutic potential. The ubiquitous role of tankyrase in cellular homeostasis and Wnt-dependent tumor proliferation brought difficulties for researchers to strike the right balance between potency and on-target toxicity. The need for novel tankyrase inhibitors with a better ADMET profile can introduce an additional regimen in treating various malignancies in monotherapy or adjuvant therapy. The development of combination therapies, including tankyrase inhibitors with or without PARP inhibitory properties, can potentially benefit the larger population of patients with unmet medical needs.

Enhancing soluble phosphate concentration in sludge liquor by pressurised anaerobic digestion.

Recovery of phosphate from wastewater is challenging, with one of the best opportunities being recovery from sludge anaerobic digestion liquor, as struvite. However, this is limited by the proportion of total phosphorous which is soluble, due to in-digester metal ion precipitation. High-pressure anaerobic digestion may enable enhanced phosphate solubility (and hence recovery potential), without the use of added acid, due to an increased liquid phase CO2 concentration. This was tested at 2, 4, and 6 bar absolute (bara) vs a 1 bara control reactor, fed with activated sludge. Increased pressure significantly (p = 0.0008), increased the fraction of phosphate that was soluble, ranging from 52% at 1 bara, to 75% at 6 bara. Model based analysis indicated that the main reason for increased solubility was pH depression (down to 6.4 at 6 bara), rather than changes in ion pairing (with carbonates) or increases in ionic activity. However, biological performance was adversely impacted, with a substantial loss in VS and COD destruction (on the order of 5%-10% absolute). No organic acid accumulation was observed. Bacterial and archaeal communities were significantly impacted (p∼0.0003-0.0005), with a shift to specific organisms, including Bacteroidales Rikenellaceae within the bacteria, and a Deep Sea Euryarchaeotal Group at 2 bara, and Methanocellaceae within the archaea at 4 and 6 bara. The work indicates that high-pressure operation is a technically viable option to improve phosphate recovery, and produce a high-methane biogas product, but that the loss of overall conversion needs to be further addressed, possibly through two-stage digestion.

Six-Month Outcomes after Restrictive or Liberal Transfusion for Cardiac Surgery.

BACKGROUND: We reported previously that, in patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive transfusion strategy was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis by hospital discharge or 28 days after surgery, whichever came first. We now report the clinical outcomes at 6 months after surgery. METHODS: We randomly assigned 5243 adults undergoing cardiac surgery to a restrictive red-cell transfusion strategy (transfusion if the hemoglobin concentration was <7.5 g per deciliter intraoperatively or postoperatively) or a liberal red-cell transfusion strategy (transfusion if the hemoglobin concentration was <9.5 g per deciliter intraoperatively or postoperatively when the patient was in the intensive care unit [ICU] or was <8.5 g per deciliter when the patient was in the non-ICU ward). The primary composite outcome was death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis occurring within 6 months after the initial surgery. An expanded secondary composite outcome included all the components of the primary outcome as well as emergency department visit, hospital readmission, or coronary revascularization occurring within 6 months after the index surgery. The secondary outcomes included the individual components of the two composite outcomes. RESULTS: At 6 months after surgery, the primary composite outcome had occurred in 402 of 2317 patients (17.4%) in the restrictive-threshold group and in 402 of 2347 patients (17.1%) in the liberal-threshold group (absolute risk difference before rounding, 0.22 percentage points; 95% confidence interval [CI], -1.95 to 2.39; odds ratio, 1.02; 95% CI, 0.87 to 1.18; P=0.006 for noninferiority). Mortality was 6.2% in the restrictive-threshold group and 6.4% in the liberal-threshold group (odds ratio, 0.95; 95% CI, 0.75 to 1.21). There were no significant between-group differences in the secondary outcomes. CONCLUSIONS: In patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive strategy for red-cell transfusion was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis at 6 months after surgery. (Funded by the Canadian Institutes of Health Research and others; TRICS III ClinicalTrials.gov number, NCT02042898 .).

Use of Osteofasciocutaneous Fibular Free Flap and Radial Head Arthroplasty in Trauma for Limb Salvage and Continued Elbow Function.

Reconstructive flaps have revolutionized the ability of surgeons to restore function and cosmesis for patients. While reconstructive flaps have been used to bridge large defects due to oncologic or congenital maladies necessitating large debridements, few cases have observed salvage flaps in traumas which provide additional challenges secondary to an injury trajectory. This case report details use of an osteofasciocutaneous fibular free flap and radial head prosthesis to restore forearm function in a 64-year-old female with a comminuted fracture of the proximal radius. The patient has sustained a 5.5 cm epiphyseal radial defect with an associated 20 × 15 cm overlying tissue defect after serial debridement. In review of the literature, only one nontraumatic case using a combined free flap and radial head prosthesis for proximal forearm defect to restore joint function has been reported. We suggest that, for proximal forearm fractures, this technique can be used to restore elbow joint function in limb salvage.

Nutrient recovery from wastewater through pilot scale electrodialysis.

Nutrient recovery performance utilising an electrodialysis (ED) process was quantified in a 30-cell pair pilot reactor with a 7.2 m2 effective membrane area, utilising domestic anaerobic digester supernatant, which had been passed through a centrifuge as a feed source (centrate). A concentrated product (NH4-N 7100 ±â€¯300 mg/L and K 2490 ±â€¯40 mg/L) could be achieved by concentrating nutrient ions from the centrate wastewater dilute feed stream to the product stream using the ED process. The average total current efficiency for all major cations over the experimental period was 76 ±â€¯2% (NH4-N transport 40%, K transport 14%). The electrode power consumption was 4.9 ±â€¯1.5 kWh/kgN, averaged across the three replicate trials. This value is lower than competing technologies for NH4-N removal and production, and far lower than previous ED lab trials, demonstrating the importance of pilot testing. No significant variation in starting flux densities and cell resistance voltage for subsequent replicate treatments indicated effective cleaning procedures and operational sustainability at treatment durations of several days. This study demonstrates that ED is an economically promising technology for the recovery of nutrients from wastewater.

Restrictive or Liberal Red-Cell Transfusion for Cardiac Surgery.

BACKGROUND: The effect of a restrictive versus liberal red-cell transfusion strategy on clinical outcomes in patients undergoing cardiac surgery remains unclear. METHODS: In this multicenter, open-label, noninferiority trial, we randomly assigned 5243 adults undergoing cardiac surgery who had a European System for Cardiac Operative Risk Evaluation (EuroSCORE) I of 6 or more (on a scale from 0 to 47, with higher scores indicating a higher risk of death after cardiac surgery) to a restrictive red-cell transfusion threshold (transfuse if hemoglobin level was <7.5 g per deciliter, starting from induction of anesthesia) or a liberal red-cell transfusion threshold (transfuse if hemoglobin level was <9.5 g per deciliter in the operating room or intensive care unit [ICU] or was <8.5 g per deciliter in the non-ICU ward). The primary composite outcome was death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis by hospital discharge or by day 28, whichever came first. Secondary outcomes included red-cell transfusion and other clinical outcomes. RESULTS: The primary outcome occurred in 11.4% of the patients in the restrictive-threshold group, as compared with 12.5% of those in the liberal-threshold group (absolute risk difference, -1.11 percentage points; 95% confidence interval [CI], -2.93 to 0.72; odds ratio, 0.90; 95% CI, 0.76 to 1.07; P<0.001 for noninferiority). Mortality was 3.0% in the restrictive-threshold group and 3.6% in the liberal-threshold group (odds ratio, 0.85; 95% CI, 0.62 to 1.16). Red-cell transfusion occurred in 52.3% of the patients in the restrictive-threshold group, as compared with 72.6% of those in the liberal-threshold group (odds ratio, 0.41; 95% CI, 0.37 to 0.47). There were no significant between-group differences with regard to the other secondary outcomes. CONCLUSIONS: In patients undergoing cardiac surgery who were at moderate-to-high risk for death, a restrictive strategy regarding red-cell transfusion was noninferior to a liberal strategy with respect to the composite outcome of death from any cause, myocardial infarction, stroke, or new-onset renal failure with dialysis, with less blood transfused. (Funded by the Canadian Institutes of Health Research and others; TRICS III ClinicalTrials.gov number, NCT02042898 .).

Liquid phase combinatorial synthesis of 1,2,5-trisubstituted benzimidazole derivatives as human DHODH inhibitors.

The synthesis of 1,2,5-trisubstituted benzimidazole derivatives was carried out using liquid phase combinatorial approach using soluble polymer assisted support (PEG5000). Synthesised compounds were characterised by FTIR, ESI-MS, 1H NMR and 13C NMR. The purity of compounds was confirmed with HPLC analysis. Compounds were also docked into the binding site of human dihydroorotate dehydrogenase (hDHODH). The synthesised compounds were screened for hDHODH enzyme inhibition assay using brequinar as standard compound. The synthesised compounds demonstrated comparative biological activity. Synthesised compounds 8d and 8e demonstrated IC50 value of 81±2nM and 97±2nM, respectively.

Treatment of Isolated Zygomatic Arch Fracture: Improved Outcomes with External Splinting.

BACKGROUND: The various approaches to reduction and fixation of isolated displaced zygomatic arch fractures have not been well studied. The authors compared established treatment methods for zygomatic arch fractures for both aesthetic and functional outcomes. METHODS: Consecutive patients with isolated zygomatic arch fractures with a minimum of 6 months' follow-up were studied in five groups: group 1, intraoral approach (no fixation); group 2, temporal approach (no fixation); group 3, coronal flap plate fixation; group 4, external splint fixation; and group 5, no surgery. Perioperative complications, facial contour symmetry (aesthetic outcome), improvement in mouth opening (functional outcome), and reoperations were compared. RESULTS: Patients undergoing external splint fixation had no perioperative complications. Coronal flap plate fixation had the highest rate of perioperative complications (46 percent), with facial nerve injury (4 percent), hematoma (8 percent), and persistent hyperesthesia (8 percent). Reoperations (fat grafting or bony reconstruction) were highest with coronal flap plate fixation (23 percent) and the temporal approach (7.7 percent); external splint fixation and the intraoral approach required no reinterventions. Patients treated with external splint fixation had the largest improvement in mean interincisor mouth opening. Mean postoperative interincisor opening in decreasing order was as follows: external splint fixation (51.6 mm), coronal flap plate fixation (47.1 mm), no surgery (39.8 mm), intraoral approach (39.6 mm), and temporal approach (38.9 mm). The highest volumetric symmetry was seen in external splint fixation (97.9 percent), followed by coronal flap plate fixation (94 percent), temporal approach (76.2 percent), intraoral approach (73 percent), and no surgery (68.3 percent). CONCLUSION: For isolated zygomatic arch fracture, patients undergoing external splint fixation had the lowest risk of perioperative complications and the greatest improvement in functional and aesthetic outcomes compared with the intraoral approach (no fixation), the temporal approach (no fixation), coronal flap plate fixation, and no surgery. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

Influence of low pH on continuous anaerobic digestion of waste activated sludge.

The influence of low pH on single stage continuous anaerobic digestion was evaluated, with the goal of increasing soluble phosphorus (P) concentration to mitigate in-reactor P precipitation. This was performed at pH 5.0, 5.5, 6.0, 6.5 and 7.0 using 1 L stirred-tank mesophilic reactors fed with sewage waste activated sludge. Low pH (5.5) caused a significant (p < 0.01) increase in soluble P concentration up to 79% of the total P, while methane yield was reduced by 50%. Total volatile fatty acids and soluble chemical oxygen demand concentrations increased from 40 to 504 mg L-1 and 600 to 2017 mg L-1 respectively, as the pH was reduced from 7.0 to 5.5. Higher concentrations of propionic acid (370-430 mg L-1) were found at low pH (5.5). The reduction in methane yield was associated with a shift in microbial community and decreased destruction of particulate organics. Acidogens dominated at low pH (< 6.0), while methanogens decreased by 88% at pH 5.5 compared to neutral pH. Apart from the loss in methanogenic and hydrolytic capacity, chemical needs for acid dosing to maintain low pH conditions, and other negative impacts of chemical dosing were identified as key limitations.

Predicting scale formation during electrodialytic nutrient recovery.

Electro-concentration of nutrients from waste streams is a promising technology to enable resource recovery, but has several operational concerns. One key concern is the formation of inorganic scale on the concentrate side of cation exchange membranes when recovering nutrients from wastewaters containing calcium, magnesium, phosphorous and carbonate, commonly present in anaerobic digester rejection water. Electrodialytic nutrient recovery was trialed on anaerobic digester rejection water in a laboratory scale electro-concentration unit without treatment (A), following struvite recovery (B), and following struvite recovery as well as concentrate controlled at pH 5 for scaling control (C). Treatment A resulted in large amount of scale, while treatment B significantly reduced the amount of scale formation with reduction in magnesium phosphates, and treatment C reduced the amount of scale further by limiting the formation of calcium carbonates. Treatment C resulted in an 87 ± 7% by weight reduction in scale compared to treatment A. A mechanistic model for the inorganic processes was validated using a previously published general precipitation model based on saturation index. The model attributed the reduction in struvite scale to the removal of phosphate during the struvite pre-treatment, and the reduction in calcium carbonate scale to pH control resulting in the stripping of carbonate as carbon dioxide gas. This indicates that multiple strategies may be required to control precipitation, and that mechanistic models can assist in developing a combined approach.

Recovery of energy and nutrient resources from cattle paunch waste using temperature phased anaerobic digestion.

Cattle paunch is comprised of partially digested cattle feed, containing mainly grass and grain and is a major waste produced at cattle slaughterhouses contributing 20-30% of organic matter and 40-50% of P waste produced on-site. In this work, Temperature Phased Anaerobic Digestion (TPAD) and struvite crystallization processes were developed at pilot-scale to recover methane energy and nutrients from paunch solid waste. The TPAD plant achieved a maximum sustainable organic loading rate of 1-1.5kgCODm(-3)day(-1) using a feed solids concentration of approximately 3%; this loading rate was limited by plant engineering and not the biology of the process. Organic solids destruction (60%) and methane production (230LCH4kg(-1) VSfed) achieved in the plant were similar to levels predicted from laboratory biochemical methane potential (BMP) testing. Model based analysis identified no significant difference in batch laboratory parameters vs pilot-scale continuous parameters, and no change in speed or extent of degradation. However the TPAD process did result in a degree of process intensification with a high level of solids destruction at an average treatment time of 21days. Results from the pilot plant show that an integrated process enabled resource recovery at 7.8GJ/dry tonne paunch, 1.8kgP/dry tonne paunch and 1.0kgN/dry tonne paunch.

A mechanistic model for electrochemical nutrient recovery systems.

Electrochemical membrane technologies such as electrodialysis have been identified as key technologies to enable nutrient recovery from wastewater. However, current electrochemical models are focused on simpler solutions than wastewater and omit key outputs such as pH, or total cell potential. A combined physico-chemical and electrochemical model was developed which includes the mechanisms of competitive transport of ions, implicit inclusion of H(+) and OH(-), pH (including ionic activity and ion pairing), different factors contributing to total cell potential and a novel method for ion exchange membrane transport. The model outputs compare well with measurements from experiments and simulate secondary effects such as electrode reactions and current leakage. Results found that membrane, rather than boundary layer or bulk resistance was the major contributor to potential drop, and that apparent boundary layers were relatively thick (3 ± 1 mm). Non-ideal solution effects such as ion-pairing and ionic activity had a major impact, particularly on multi-valent Ca(2+) ions, which enhances the capability of electrodialysis to recover monovalent nutrient ions such as K(+) and NH4(+). Decreased resistivity of ion exchange membranes to specific ions (for example, in this case nitrate) could also be detected. The methods here are validated using a comparatively simple synthetic solution of five ionic components, but are able to be easily scaled for a more complex solution, and are also compatible with additional mechanisms such as precipitation, fouling, and scaling.

The antiplaque efficacy of white tea extract mouthrinse.

OBJECTIVE: This study was conducted to assess the antiplaque efficacy of a mouthwash containing white tea. It also assessed the antibacterial properties of white tea against Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetemcomitans (Aa) in vitro. MATERIALS AND METHODS: Forty-five subjects with healthy periodontium were randomly chosen and were divided into three groups and advised to use mouthwashes A, B, and C (Group A, white tea; Group B, distilled water [placebo]; Group C, chlorhexidine) for 4 days. They were advised to refrain from any kind of mechanical oral hygiene techniques. Plaque index (PI) was checked on day 1 and 5. In vitro testing for against Pi, Pg, and Aa against white tea extract was undertaken. RESULTS: PI significantly increased from day 1 to day 5 (P < 0.01) in Groups A, B, and C. In inter-group comparison, there was a statistical significant difference between white tea mouthrinse group and placebo group, chlorhexidine group and placebo group and also chlorhexidine group and white tea mouthrinse group. However, chlohexidine showed superior antiplaque activity. In vitro test, white tea showed effective inhibition against all three bacterial strains Pi, Pg, and Aa at 1% concentration. CONCLUSION: White tea mouthrinse potently inhibits plaque formation although not as comparable to chlorhexidine mouthrinse. Hence, for those preferring herbal products, white tea mouthrinse is a good option.