Recovery Parameters Research Articles

A Validated RP-HPLC method for related substances of Dabigatran etexilate mesylate

The scope of this research work was to develop a reverse-phase liquid chromatographic method for the quantification of related impurities of dabigatran and to validate the method according to ICH guidelines. Chromatographic conditions were optimised with Poroshell SB C18, 150mm, 4.6mm, 2.7µm particle size column, mixer of Phosphate buffer with phosphoric acid in water and acetonitrile with percentage of 10:90 (v/v) as solvent-A and acetonitrile and buffer with a percentage of 70:30 (v/v) as solvent-B. Gradient compassion mode is employed for mobile phase delivery with a flow rate of 0.8 mL/min. Stationary phase was maintained at 35°C temperature and detection at 230 nm, with 10 µL of sample injection volume. Water and acetonitrile in the percentage 30:70(v/v) were used as a diluent. The developed RP-HPLC method was validated according to ICH guidelines. LOD and LOQ values for dabigatran its impurities were in the range from 33 to 55 ppm and 112 to 168 ppm correspondingly. Method validation results for all the parameters are meeting the ICH guidelines acceptance criteria for the parameters of robustness, ruggedness, linearity, reproducibility and recovery. The proposed method was found to be suitable for the quantitative determination of potential impurities in the bulk samples of Dabigatran etexilate mesylate API.

Relationship between training load and recovery in collegiate American football players during pre-season training

ABSTRACT Background: The purpose of this study was to examine the relationship between training load and next-day recovery in collegiate American football (AF) players during pre-season. Methods: Seventeen athletes (Linemen, n = 6; Non-linemen, n = 11) participated in the 14-day study wearing monitoring (accelerometer + heart rate) sensors during on-field practice sessions throughout pre-season to assess the physiological (PL), mechanical load (ML) and recording of session RPE (sRPE load) immediately post-practice. Prior to practice, participants completed a drop-jump reactive strength index (RSI) test and reported perceived recovery status (PRS). Loaded counter movement vertical jump was assessed before and after pre-season. Results: For every one unit increase in sRPE load, RSI declined by 0.03. Non-linemen had a lower RSI value of 73.1 units compared to linemen. For every one unit increase in ML, the PRS decreased by 0.01. Non-linemen recorded higher average ML during week 2 (ES = 1.17) compared to linemen. Non-linemen recorded higher RSI values in weeks 1 (ES = −1.41) and 2 (ES = −1.72) compared to linemen. All training load and recovery parameters were lower week 2 compared to week 1 (p < 0.05) for all players. Conclusions: Next-day RSI values were influenced by sRPE load while next-day PRS appears to be more influenced by ML. No difference in PL or sRPE load was observed been groups despite non-linemen completing a higher ML throughout the preseason. A combination of training load and recovery metrics may be needed to monitor the fatigue and state of readiness of each player.

Analysis of the recovery phase after maximal exercise in children with repaired tetralogy of Fallot and the relationship with ventricular function.

BackgroundFew studies demonstrate delayed recovery after exercise in children and adults with heart disease. We assess the recovery patterns of gas exchange parameters and heart rate (HR) in children with repaired Tetralogy of Fallot (rToF) compared to healthy peers and investigate the correlation with ventricular function and QRS duration.Methods45 children after rToF and 45 controls performed a maximal incremental cardiopulmonary exercise test. In the subsequent recovery period, patterns of VO2, VCO2 and HR were analysed. Half-life time (T1/2) of the exponential decay and drop per minute (Recmin) were compared between groups. In the rToF group, correlations were examined between the recovery parameters and QRS-duration and ventricular function, described by fractional shortening (FS) and tricuspid annular plane systolic excursion (TAPSE) measured at baseline prior to exercise.ResultsRecovery of VO2 and VCO2 was delayed in rToF patients, half-life time values were higher compared to controls (T1/2VO2 52.51 ±11.29 s vs. 44.31 ± 10.47 s; p = 0.001 and T1/2VCO2 68.28 ± 13.84 s vs. 59.41 ± 12.06 s; p = 0.002) and percentage drop from maximal value was slower at each minute of recovery (p<0.05). Correlations were found with FS (T1/2VO2: r = -0.517; p<0.001; Rec1minVO2: r = -0.636, p<0.001; Rec1minVCO2: r = -0.373, p = 0.012) and TAPSE (T1/2VO2: r = -0.505; p<0.001; Rec1minVO2: r = -0.566, p<0.001; T1/2VCO2: r = -0.466; p = 0.001; Rec1minVCO2: r = -0.507, p<0.001), not with QRS-duration. No difference was found in HR recovery between patients and controls.ConclusionsChildren after rToF show a delayed gas exchange recovery after exercise. This delay correlates to ventricular function, demonstrating its importance in recovery after physical activity.

Enhanced recovery after surgery and mini-invasive approaches in rectal cancer surgery – short-term outcomes

The aim of this study was to evaluate short-term outcomes of patients undergoing mini-invasive rectal resection within an ERAS (enhanced recovery after surgery) protocol. Aprospectively managed database of patients undergoing rectal operations performed at our department between January 2015 and April 2020 was retrospectively analyzed. An ERAS protocol was implemented into clinical practice at our department in April 2016 and mini-invasive rectal procedures in May 2016. The ERAS group consisted of all patients who underwent mini-invasive rectal resections or amputations within the ERAS protocol. The control group consisted of patients who underwent open procedures and received standard perioperative care. The extracted data included basic patient characteristics, surgical data, postoperative recovery parameters, 30-day morbidity, length of postoperative stay and 30-day rehospitalization. Atotal of 110 patients were included in the study: 67 patients in the ERAS group and 43 in the control group. Within the ERAS group 47 patients underwent robotic procedures and 20 had laparoscopic procedures. Patients in the ERAS group had significantly better clinical and laboratory recovery parameters except for postoperative nausea and vomiting. Asignificantly lower incidence of paralytic ileus (20.9% vs. 3%) and ashorter length of postoperative stay (13 days vs. 9 days) was found in the ERAS group. The rehospitalization rate and 30-day morbidity were not different between the ERAS and control group. Implementation of the ERAS protocol in combination with mini-invasive approaches leads to better short-term postoperative outcomes after rectal surgery.

Acute Peritoneal Dialysis With Percutaneous Catheter Insertion for COVID-19–Associated Acute Kidney Injury in Intensive Care: Experience From a UK Tertiary Center

IntroductionDuring the coronavirus disease 2019 (COVID-19) pandemic in 2020, high rates of acute kidney injury (AKI) in critically unwell patients are being reported, leading to an increased demand for renal replacement therapy (RRT). Providing RRT for this large number of patients is proving challenging, and so alternatives to continuous renal replacement therapies (CRRT) in the intensive care unit (ICU) are needed. Peritoneal dialysis (PD) can be initiated immediately after percutaneous insertion of the catheter, but there are concerns about impact on ventilation and RRT efficacy. We sought to describe our recent experience with percutaneous catheter insertion and peritoneal dialysis in patients in the ICU with COVID-19 infection.MethodPatients were selected according to local protocol, and catheters were inserted percutaneously by experienced operators using a Seldinger technique. Sequential Organ Failure Assessment (SOFA) score and ventilation requirements were recorded at the time of insertion and 24 hours later. Procedural complications, proportion of RRT provided by PD, renal recovery, and RRT parameters (serum potassium and maximum base excess) during PD were assessed.ResultsPercutaneous PD catheters were successfully inserted in 37 of 44 patients (84.1%) after a median of 13.5 days (interquartile range [IQR] = 10.0, 20.3 days) in the ICU. No adverse events were reported; SOFA scores and ventilation requirements were comparable before and after insertion; and adequate RRT parameters were achieved. The median proportion of RRT provided by PD following catheter insertion was 94.6% (IQR = 75.0, 100%).ConclusionPeritoneal dialysis provides a safe and effective alternative to CRRT in selected patients with AKI and COVID-19 infection requiring ventilation on intensive care.

Chemical and Leaching Behavior of Construction and Demolition Wastes and Recycled Aggregates

Construction and demolition wastes are widely recognized as the main waste stream in the EU, and their recycling and recovery is an important issue in sustainable building industry development. The composition of construction and demolition wastes is highly heterogeneous and is influenced by several factors, including the raw materials and construction products used. The environmental performance of these materials are therefore considerably variable and, in some cases, do not comply with the regulatory limits established to ensure the protection of the natural environment. In this context, this paper presents a data analysis on the environmental behavior of construction and demolition wastes and recycled aggregates in terms of both chemical composition and the release of contaminants according to a leaching test. Subsequently, the most critical parameters for recovery were identified and statistically evaluated. The leaching results showed that SO4, Cu, and COD are critical compounds for both CDWs and RAs.

Modeling housing recovery after the 2018 Lombok earthquakes using a stochastic queuing model

Post-earthquake housing recovery monitoring is necessary, especially since the housing sector usually represents 50 percent of the total monetary disaster loss. However, very scarce recovery data, in addition to the complexities of the recovery process, make modeling housing recovery very difficult. Time-based stochastic models, which are commonly used in well-known frameworks such as the U.S. Federal Emergency Management Agency’s HAZARD-US (HAZUS), do not explicitly capture how the recovery process occurs in real life. In this article, we introduce a stochastic queuing model that considers the total number of damaged buildings, the damage distribution, resource constraints, and government-led reconstruction prioritization strategies. We applied our model to seven regions affected by the 2018 Lombok earthquakes, which destroyed over 226,000 residential buildings. In this study, we use publicly available daily data of the reconstruction progress obtained by local authorities for all damaged buildings. Using that dataset, we present recovery parameters for the Lombok region, including delay and reconstruction times. These parameters are an improvement over parameters currently available, which only apply to the U.S. region. Furthermore, we show that our model captures the observed recovery trajectory disaggregated by damage states, which provides insights into how the different building damage states recover individually. Results show that our queuing model reduces the root mean squared error (RMSE) of the recovery trajectory by 31.58% and is better able to represent the observed overall recovery trajectory compared to a time-based stochastic model.

Diagnosis and Compensation of Control Program, Sensor and Actuator Failures in Nonlinear Systems Using Hierarchical State Space Checks

Autonomous systems with nonlinear dynamics need to be extremely resilient to errors in sensors, actuators and on-board electronics for the purpose of overall vehicle safety. Prior research has focused on control-theoretic methods with significant computational burden with a focus on failures in actuation. In contrast, we propose the use of hierarchical machine learning driven state space checks that detect and diagnose errors in control program execution, sensors and actuators with high sensitivity and low latency. Each check produces a time-varying error signal that facilitates effect-cause diagnosis of the system, while allowing rapid parameter estimation from each check. Since the checks are over small subsets of system parameters, estimation is fast and accurate. The estimated parameters are then used to reconfigure the system controller parameters for rapid system recovery. We use a quadcopter system to demonstrate and validate our approach. Controller, sensor and actuator errors can be detected, diagnosed and compensated using a common checking platform with low computational overhead. The technique is validated on a quadcopter hardware test vehicle.

Review on extraction of polyhydroxyalkanoates and astaxanthin from food and beverage processing wastewater

The recovery of value-added products from food and beverage processing wastewater, polyhydroxyalkanoates, and astaxanthin, via various chemical and microbiological extraction techniques has been summarized in this contribution. While wastewaters from several food industries like olive oil, brewery, starchy, and agro-cultural have been utilized to produce polyhydroxyalkanoates as an alternative to the petrochemical sources, seafood wastewaters such as mussel processing, shrimp cooking, and chitin production have been used to recover astaxanthin. In these studies, the wastewater's carbon content has been found as an essential parameter for the recovery of polyhydroxyalkanoates and astaxanthin. The type of additional nitrogen source, microorganism properties, ambient conditions, and polymer extraction methods were mostly examined parameters for the polyhydroxyalkanoate recovery. Olive oil mill wastewater has been presented as one of the most promising industries for the recovery of polyhydroxyalkanoate with the highest polymer yield of 4.93 g L−1. Shrimp cooking wastewaters provide one of the highest astaxanthin yields as 10–13 μg mL−1. In addition to summarizing polyhydroxyalkanoates and astaxanthin yields from various wastewaters, technological obstacles and solutions regarding efficient extraction and large scale production have been discussed in this review.

The Effect of Perioperative Lidocaine Infusion on Postoperative Pain and Postsurgical Recovery Parameters in Gynecologic Cancer Surgery.

The primary objective of this prospective nonblinded randomized study was to investigate the effect of perioperative systemic lidocaine infusion on pain control after major gynecologic oncology surgery. Patient-reported outcomes, postoperative recovery parameters, and complications were secondary endpoints of the study. Seventy-five patients with American Society of Anesthesiologists I-III were divided into 3 groups based on perioperative analgesia methods-(1) opioid group: patient-controlled analgesia (PCA) with morphine; (2) lidocaine group: perioperative intravenous lidocaine infusion, plus PCA with morphine; and (3) the epidural group: PCA with bupivacaine. The Visual Analog Scale (VAS) was recorded postoperatively. In addition, nausea-vomiting, time to first oral intake, time to first ambulation, time to first flatus, and length of hospital stay were recorded. VAS scores (rest) at 24 hours and VAS scores (cough) at 12 and 24 hours were significantly lower in the epidural group than in the opioid group (P<0.05). VAS scores were found to be similar between the lidocaine and epidural group. The nausea-vomiting incidence was lower in the lidocaine group than in the opioid group (P˂0.05). Compared with the other 2 groups, the first flatus time was shorter in the lidocaine group (P<0.05). Perioperative lidocaine infusion is effective as epidural analgesia, which is often advocated as the gold-standard analgesic technique for abdominal surgery and is superior to the others in terms of time to first flatus and the incidence of nausea-vomiting.

Nociception level-guided opioid administration in radical retropubic prostatectomy: a randomised controlled trial

BackgroundThis RCT investigated the effect of opioid titration by three different nociception monitoring devices or clinical signs during general anaesthesia. MethodsNinety-six patients undergoing radical retropubic prostatectomy with propofol/remifentanil anaesthesia were randomised into one of four groups to receive remifentanil guided by one of three nociception monitoring devices (surgical pleth index [SPI], pupillary pain index [PPI], or nociception level [NOL]) or by clinical judgement (control). Intraoperative remifentanil requirement was the primary endpoint, whereas recovery parameters and stress hormone levels were secondary endpoints. ResultsThe mean [95% confidence interval {CI}] remifentanil administration rate differed between the groups: control 0.34 (0.32–0.37), SPI 0.46 (0.38–0.55), PPI 0.07 (0.06–0.08), and NOL 0.16 (0.12–0.21) μg kg−1 min−1(P<0.001). Intraoperative cessation of remifentanil administration occurred in different numbers (%) of patients: control 0 (0%), SPI 1 (4.3%), PPI 18 (75.0%), and NOL 11 (47.8%); P=0.002. The area under the curve analyses indicated differences in cumulative cortisol levels (mg L−1 min−1) amongst the groups: control 37.9 (33.3–43.1), SPI 38.6 (33.8–44.2), PPI 72.1 (63.1–82.3), and NOL 54.4 (47.6–62.1) (mean [95% CI]). Pairwise group comparison results were as follows: control vs SPI, P=0.830; control vs PPI, P<0.001; control vs NOL, P=0.001; SPI vs PPI, P<0.001; SPI vs NOL, P=0.002; and PPI vs NOL, P=0.009. ConclusionsThe nociception monitoring devices and clinical signs reflect the extent of nociception differently, leading to dissimilar doses of remifentanil. Very low remifentanil doses were associated with an increase and higher remifentanil doses were accompanied by a decrease in serum cortisol concentrations. Use of nociception monitoring devices for guiding intra-operative opioid dosing needs further validation. Clinical trial registrationNCT03380949.

Understanding the behavioral trends of the effect of water salinity and sand size on oil recovery in sandstone reservoirs

Enhanced oil recovery techniques are deployed to subsequently improve oil production having already employed primary or secondary recovery techniques or both methods simultaneously. Literature have shown that salinity impacts on oil recovery due to wettability alteration, but grain size which is closely related to the mechanical behavior and petrographical properties is also one of the main parameters controlling the phenomenon. There is need to investigate the effect of these two parameters in oil recovery. This study considered the effects of water salinity in the range of 0 to 20,000 ppm and sand grains of 45 to 300 µm on oil recovery. Flooding experiments and statistical analyses of the designed experiment was used to determine the residual oil saturation. The properties of sand samples such as bulk and pore volumes, porosity as well as, wet and dry weight for the various groups were also analyzed. Gauss-Newton algorithm with Levenberg-Marquardt modifications were the numerical scheme executed in MATLAB to formulate residual oil saturation model. The optimum percentage recovery for the core flooding experiment in each groups are 82.4%, 81.1%, 79.4%, 81.1% and 78.8% for A4, B4, C4, D4 and E5 respectively. Based on the experimental results, the 300 µm sand grains and salt concentration of 15,000 ppm should be used for operations in this reservoirs because, those conditions guarantee oil recovery as high as 82%. High oil recoveries correspond to low residual oil saturation and vice-versa. The recovered residual oil percentage had no direct correlations with the net dry and wet weights of the samples. The 45-micron grains had the least pore volume and it was observed that the percentage recoveries had no direct correlations with the core sample weights. During validation of the formulated residual oil saturation model, the model gave a good prediction of the experimental data within the 95% confidence interval, and from the statistical analyses, residual oil saturation decreased with decrease in water salinity. Thus, the larger the size of a grain, the lower its superficial area exposed to the wetting and non-wetting fluids which subsequently impacts on oil recovery.

Inhalation of low-dose desflurane prevents the hemodynamic instability caused by target-controlled infusion of remifentanil and propofol during laparoscopic gynecological surgery: A randomized controlled trial.

The objective of the present study was to determine whether the addition of inhaled desflurane is superior to remifentanil-propofol total intravenous anesthesia (TIVA) alone in patients undergoing laparoscopic gynecological surgery. A total of 60 patients who were scheduled to undergo laparoscopic gynecological surgery were prospectively enrolled and randomly allocated to receive either propofol-remifentanil (PR group; n=30) or combined propofol-remifentanil and low-dose desflurane (PRD group; n=30) for the maintenance of anesthesia. Hemodynamics [mean arterial pressure (MAP); heart rate (HR)], recovery parameters and complications were recorded. The results of the present study indicated that the addition of desflurane significantly reduced the amount of propofol and remifentanil that was administered in the PRD group, compared with that in the PR group. MAP and HR were significantly higher at T3 (5 min post-pneumoperitoneum), but significantly lower at T4 (removal of pneumoperitoneum needle) and T5 (post-operation immediately) in the PR group, compared with the PRD group. Moreover, MAP and HR were significantly altered at multiple time points within the PR group; however, they were relatively stable in the PRD group. There were no significant differences in the recovery parameters and complications between the two groups. In conclusion, combining low-dose desflurane with PR may represent an efficient anesthesia regimen to prevent the hemodynamic instability of TIVA in patients undergoing laparoscopic gynecological surgery.

DIFFERENCE OF ANATOMY INFORMATION MRI KNEE JOINT ON VARIATION OF TIME REPETITION SEQUENCES STIR IN SAGITTAL SLICES

Background: Time Repetition (TR) is one of the main parameters of Inversion Recovery. The purpose of this study to determine differences in anatomical MRI information on the variation of the knee joint TR sequences STIR Sagittal slices. Method: Type of research is experimental. The study was conducted with MRI 1.5 Tesla. Data in the form of 42 image sequences STIR MRI knee joint with TR 3500, 4000, 4500, 5000, 5500, 6000, and 6500 ms. Anatomical assessments on the anterior cruciate ligament, posterior cruciate ligament, articular cartilage, and meniscus were performed by a radiologist. Data analyzed by Friedman and Wilcoxon test. Result: The results showed that there were differences in the MRI anatomical information of the knee joint of the STIR sagitas slice in the TR variation with p-value &lt; 0.001. There is a difference in anatomical information between TR 5000 and 6000 ms (p-value = 0.034), TR 5000 and 6500 ms (p-value = 0.024), TR 5500 and 6500 ms (p-value = 0.038). There is no difference in anatomical information between TR 4500 and 5000 ms (p-value = 0.395), TR 4500 and 5500 ms (p-value = 0.131), TR 4500 and 6000 ms (p-value = 0.078), TR 4500 and 6500 ms (p-value = 0.066), TR 5000 and 5500 ms (p-value = 0.414), TR 5500 and 6000 ms (p-value = 0.102), TR 6000 and 6500 ms (p-value = 0.083). Conclusion: The optimal value to produce anatomical information of the knee joint sagittal MRI sequences STIR is TR 4500 ms.

Effect of differential music tempo on post-exercise cardiovascular recovery parameters in hypertensive individuals: a randomised control trial

Hypertensive individuals tend to have autonomic dysfunction indicated by sympathetic dominance or delayed parasympathetic reactivation. A complimentary therapy such as music following exercise is considered to be beneficial in improving autonomic recovery. The purpose of this study was to assess the effect of differential music tempo on post-exercise cardiovascular recovery parameters in hypertensive individuals. Thirty hypertensive individuals were recruited for the present study which were randomly allocated to no music (n=10), slow music (n=10) and fast music (n=10) group. Participants in all three groups were subjected to submaximal exercise bout by Harvard step test. The cardiovascular recovery parameters i.e. heart rate recovery (HRR), blood pressure recovery (BPR) and rating of perceived exertion recovery (RPER) were assessed in all three groups after 1 min, 2 min and 3 min following termination of exercise. A significant decline was observed in HRR (P=0.002) and RPER (P=0.008) following exercise in slow music group as compared to fast and no music while no significant differences were observed in BPR between the three groups. The study concluded that music accelerates post-exercise recovery and slow music has greater effect as compared to fast or no music. These findings may have potential implications in the cardiovascular recovery dynamics in hypertensive individuals participating in submaximal exercise.

Can mode of anaesthesia interfere with the discharge in patients undergoing day care ureteroscopic surgeries? A randomized control trial comparing general with spinal anaesthesia

Improvement in Surgical and Anaesthetic techniques allows even complex surgeries to be performed as day care cases. The objective of the study is to compare the recovery parameters of patients undergoing anaesthesia for ambulatory surgeries under General or Spinal Anaesthesia.After approval by IEC, this study was performed in 60 patients undergoing elective ureteroscopic procedures. Patients were Randomized to receive either General anaesthesia (Group GA: n=30) or Spinal Anaesthesia (Group GA: n=30). GA was induced using standard protocols with airway maintained spontaneously using LMA. In group SA patients received 1.5 ml 0.75% Isobaric Ropivacaine for providing anaesthesia. Vitals were recorded in both the groups throughout the procedure. In addition to intra operative haemodynamics, the onset of duration and percentage of patients achieving complete sensory &amp; motor block was also recorded in SA group. Patients were kept in phase I recovery till score of Aldrete 9 was reached. In phase II recovery (PACU) the percentage of patients sitting at 180 min, standing at 300 min and walking at 360 min were recorded. The psychomotor skills of patients were assessed using digit symbol substitution test (DSST) before discharging from phase II recovery. The main criteria for discharging patients from phase II recovery was Post Anaesthesia Discharge scoring (PADSS). Patients were discharged from phase II recovery on reaching PADSS &amp;#60;10. Seventy three patients were enrolled and 60 patients completed the study. The onset of sensory and motor block in Group SA was 6.61±0.83 min and the onset of motor block was 9.48±0.91 min. Percentage of patients achieving complete sensory &amp; motor block was 71%. The duration of sensory block was 208± 17.95 min and the duration of motor block was 182.07±15.98. Patients in group GA took 221.07± 4.97 and Group SA took 110.72± 7.04 min to reach Aldrete score of 10 (p value &amp;#60;0.05). At 180 min only 22.33% patients in group GA were able to sit, while in Group SA it was 70 (p value &amp;#60;0.05). The comfort score assessed by surgeon was excellent in group GA (4/4) and was only satisfactory (2/4) in Group SA. There was no difference in pain perception or PADSS at 360 min or psychomotor skills tested by Digital symbol substitution test (DSST).The technique of Anaesthesia doesn’t interfere with readiness of patients to discharge home in terms of maintain stable vitals, pain or side effects. Isobaric Ropivacaine was found to be a poor choice for providing spinal anaesthesia due to slow onset of sensory block, inability to achieve complete motor block thus providing difficulty to operating surgeon.

Increased soybean tolerance to water deficiency through biostimulant based on fulvic acids and Ascophyllum nodosum (L.) seaweed extract

To meet the growing demand for soybean it is necessary to increase crop yield, even in low water availability conditions. To circumvent the negative effects of water deficit, application of biostimulants with anti-stress effect has been adopted, including products based on fulvic acids and Ascophyllum nodosum (L.) seaweed extracts. In this study, we determined which formulation and dosage of a biostimulant is more efficient in promoting the recovery of soybean plants after stress due to water deficit. The experiment was conducted in a greenhouse, in a double-factorial randomized block design with two additional factors, four repetitions and eleven treatments consisting of three biostimulant formulations (F1, F2 and F3), and three dosages (0.25; 0.50 and 1.0 kg ha−1); a control with water deficit and a control without water deficit. Soybean plants were kept at 50% of the pot's water capacity for three days, then rehydrated and submitted to the application of treatments with biostimulant. After two days of recovery, growth, physiological, biochemical and yield parameters were evaluated. All plants that received the application of the biostimulant produced more than the water-stressed control plants. The biostimulant provided higher photosynthetic rates, more efficient mechanisms for dissipating excess energy and higher activities of antioxidant enzymes. Plants treated with biostimulant were more efficient in the recovery of the metabolic activities after rewatering, resulting in increased soybean tolerance to water deficit and reduced yield losses. The best result obtained was through the application of formulation 2 of the biostimulant at a dosage of 0.25 kg ha−1.

Optimization of manganese recovery from groundwater treatment sludge for the production of highly-efficient Cu(II) and Pb(II) adsorbents

Manganese is one of the main components of groundwater treatment sludge. Meanwhile, copper (Cu) and lead (Pb) ions are usually present in various metal plating spent rinse waters and their removal prior to effluent release is of great importance to mitigate the adverse effects of these metals on human health and the environment. In this study, manganese recovery from groundwater treatment sludge by reductive acid leaching was optimized to produce manganese dioxide adsorbents for the competitive removal of Cu(II) and Pb(II) from simulated electroplating wastewaters. Box–Behnken design was used to optimize manganese recovery and analyze the two-parameter interactions of reductive leaching parameters for manganese recovery from the sludge, namely: sulfuric acid concentration, hydrogen peroxide dosage and sludge mass. Results showed that manganese recovery via reductive acid leaching was found to be more dependent on sludge mass than on sulfuric acid concentration and hydrogen peroxide dosage. Analysis of the elemental adsorbent composition revealed a 72.47: 27.53 manganese-to-oxygen ratio, while the evaluation of the adsorbent surface functional groups confirmed the presence of hydroxides and manganese oxides. Adsorbent point-of-zero-charge was determined at pH 6.0. Adsorption capacities for Pb(II) and Cu(II) reached 177 and 118 mg g−1, respectively. Metal uptake for both adsorbates conformed with the extended Langmuir isotherm, implying monolayer adsorption, while film diffusion was the rate-limiting mechanism. Overall, the findings of this study demonstrate high manganese recovery from groundwater treatment sludge and the production of highly-efficient adsorbents for the treatment of heavy metal-containing industrial effluents.

Optimization of Process Parameters of Rhamnolipid Treatment of Oily Sludge Based on Response Surface Methodology.

Oily sludge is a hazardous waste. If not handled properly, it can not only pollute the environment but also endanger human health. This study is the first to use a response surface method to optimize the main parameters of rhamnolipid-based recovery of oil from oily sludge. Using rhamnolipids as the cleaning agent and the oil recovery fraction as the evaluation index, the factors affecting the cleaning efficiency of oily sludge were optimized. The aforementioned sludge was obtained from the Tarim Oilfield. A single-factor experiment was conducted to determine the optimal range of the dosage, liquid–solid ratio, pH value, and time. The Box–Behnken response surface method was used to investigate the influence of each variable on the residual oil fraction of the oily sludge, and the dosage, pH value, and time were found to have a significant impact. The model optimization results show that the best process conditions for rhamnolipid-based recovery of oil are as follows: rhamnolipid dosage = 167.785 mg/L; liquid–solid ratio = 4.589:1; pH = 9.618; time = 1.627 h. Under optimal conditions, the model-predicted oil recovery fraction and the actual oil recovery fraction were 85.15 and 82.56%, respectively; the relative error between the predicted and the actual values was 2.59%. These results indicate that the model results are reliable. The solid residue after the cleaning was also analyzed to gain an in-depth understanding of the cleaning process. This study determined the feasibility of a rhamnolipid-based solution for the treatment of oily sludge and oil-contaminated soil.

Cross-validated Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging Quantitation Protocol for a Pharmaceutical Drug and Its Drug-Target Effects in the Brain Using Time-of-Flight and Fourier Transform Ion Cyclotron Resonance Analyzers.

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is an established tool in drug development, which enables visualization of drugs and drug metabolites at spatial localizations in tissue sections from different organs. However, robust and accurate quantitation by MALDI-MSI still remains a challenge. We present a quantitative MALDI-MSI method using two instruments with different types of mass analyzers, i.e., time-of-flight (TOF) and Fourier transform ion cyclotron resonance (FTICR) MS, for mapping levels of the in vivo-administered drug citalopram, a selective serotonin reuptake inhibitor, in mouse brain tissue sections. Six different methods for applying calibration standards and an internal standard were evaluated. The optimized method was validated according to authorities’ guidelines and requirements, including selectivity, accuracy, precision, recovery, calibration curve, sensitivity, reproducibility, and stability parameters. We showed that applying a dilution series of calibration standards followed by a homogeneously applied, stable, isotopically labeled standard for normalization and a matrix on top of the tissue section yielded similar results to those from the reference method using liquid chromatography–tandem mass spectrometry (LC–MS/MS). The validation results were within specified limits and the brain concentrations for TOF MS (51.1 ± 4.4 pmol/mg) and FTICR MS (56.9 ± 6.0 pmol/mg) did not significantly differ from those of the cross-validated LC–MS/MS method (55.0 ± 4.9 pmol/mg). The effect of in vivo citalopram administration on the serotonin neurotransmitter system was studied in the hippocampus, a brain region that is the principal target of the serotonergic afferents along with the limbic system, and it was shown that serotonin was significantly increased (2-fold), but its metabolite 5-hydroxyindoleacetic acid was not. This study makes a substantial step toward establishing MALDI-MSI as a fully quantitative validated method.