Ion-Specific Bubble Coalescence Dynamics in Electrolyte Solutions.

Bubble coalescence time scale is important in applications such as froth flotation, food and pharmaceutical industries, and two-phase thermal management. The time scale of coalescence is sensitive to the dissolved ions. In this study, we investigate the evolution of a thin electrolyte film between a bubble and a hydrophilic substrate during coalescence. We present a thin-film equation-based numerical model that accounts for the dependence of the surface tension gradient and electric double layer (EDL) on the concentration of ions at the air-liquid interface. The influence of Marangoni stresses and the EDL on the hydrodynamics of drainage determines the coalescence time scale. We show that the electrolytes, such as NaCl, Na2SO4, and NaI retard coalescence, in contrast to HCl and HNO3 that have little effect on the coalescence time scale. We also show that the drainage of the electrolyte films with higher concentrations is retarded due to increased Marangoni stresses at the air-water interface. The slow drainage triggers an early formation of the dimple in the thin film, thus trapping more fluid within, which further decreases the drainage rate. For a hydrophilic substrate, EDL along with van der Waals for a given concentration governs the final dynamics of thin films, eventually resulting in a stable thin layer of the electrolyte between the bubble and the substrate. The stabilizing thickness reduces by an order of magnitude as the NaCl concentration increases from 0.01 to 10 mM. For Na2SO4 solution, the film is stabilized at a smaller thickness due to higher valency cations resulting in higher screening of the EDL repulsion.

A device for sorting soft capsules in a microchannel flow.

The sorting of deforming capsules of varying stiffnesses is a challenging problem that finds applications in areas such as the pharmaceutical and food industries. Recent studies have shown that various flow configurations can be used to segregate the capsules. A lack of inertia in the microchannels makes the design of such devices extremely challenging. In this context, we propose a sorting device, which consists of capsules going through a tapered slit section. Using numerical simulations, we show that the proposed device is able to achieve significant levels of sorting with a compact setup. The design parameters can be conveniently adjusted, thus making it easier to extend the use of the device to a large range of stiffnesses.

High-Resolution PM2.5 Emissions and Associated Health Impact Inequalities in an Indian District.

Health and livelihood impacts from ambient air pollution among populations in developing countries are disproportional. These disparities are often overlooked due to a lack of information on microlevel emission data, especially in smaller cities and rural areas. The current work in an Indian district, Saharanpur, proposes the use of novel data sets to estimate microlevel emissions from air-polluting infrastructure sectors in urban and rural areas for use in pollutant transport models. Health impacts estimated based on the surface PM2.5 concentration suggest that the rate of premature deaths is 158 (95% CI: 122-163) and 143 (95% CI: 65-151) deaths per 100 000 people in urban and rural areas, respectively. Sixty-eight percent of the 6372 (95% CI: 3321-6987) annual premature deaths occurs in rural areas. Depicting higher contribution-exposure disparities among socioeconomic groups, the study observed that compared to their contribution to air pollution, low socioeconomic status (SES) groups in the region experience 6,7, 7, and 26% more premature deaths from PM2.5 exposure for industries, household cooking fuel burning, open waste burning, and transportation, respectively. The majority of disability-adjusted life years (DALYs) in the study domain are observed in economically weaker worker categories. Reduced income due to the loss of these life years will significantly impact these groups due to their dependence on daily wages for basic life necessities. Microlevel pollution mitigation policies with a focus on these inequalities are critical for promoting environmental equity and justice.

Is Paracetamol Better than Diclofenac Sodium in Management of Postoperative Pain and Edema Following Major Maxillofacial Surgeries?

Introduction: Paracetamol is an optimal non-opioid analgesic and holds considerable advantages over NSAIDs in managing post-operative pain. Literature to date doesn't provide substantial documentation of it's efficacy and safety in major oral and maxillofacial surgeries. The study is designed to compare the effectiveness of intravenous paracetamol with diclofenac sodium for controlling post-operative pain and edema in major oral and maxillofacial surgeries. Method: The double-blind randomised prospective study includes 140 healthy patients with ASA grades I and II. Patients were divided into Group A (1gm paracetamol) and B (75 mg diclofenac sodium), 70 patients each, undergoing similar surgical procedures. VAS and VRS were assessed for pain and thread method for measuring swelling. Mouth opening in space infections was measured with calliper and scale. Results: Independent samples t-test and chi-square test showed longer pain-free interval, more interval between first and second dose, lesser number of doses required in Group A than Group B (p-value < 0.05). Independent samples t-test and Mann-Whitney test showed faster resolution of swelling in Group A (p-value < 0.05). Independent samples t-test showed lesser time taken for resolution of trismus in space infections in Group A (p-value < 0.05). Discussion: Paracetamol 1 g was found to be an effective analgesic with less adverse effects. It is superior non-opioid analgesic in reducing the intensity of post-operative pain and swelling, also requires less number of doses than diclofenac sodium in major surgeries. Patients treated with paracetamol had better quality of life during post-operative period.

Bimodal Approach: A Key to Manage a Case of Traumatic Superior Orbital Fissure Syndrome.

An unusual complication associated with maxillofacial trauma is the superior orbital fissure syndrome (SOFS). Trauma-related SOFS often presents within 48 h of injury, but presentation can be delayed by several days. This article sums up the particulars of the syndrome and treatments done in the literature and discusses our experience of managing this complex case.

High resolution vehicular exhaust and non-exhaust emission analysis of urban-rural district of India.

Air quality deterioration due to vehicular emissions in smaller Indian cities and rural areas remains unacknowledged, even though the situation is alarmingly similar to megacities. The resulting lack of knowledge on travel behavior and vehicle characteristics impacts accuracy of emission studies in these regions. This study uses a novel approach and appropriate primary and secondary data sets to allocate vehicular activities (vehicle population and vehicle kilometer travelled) and associated emissions at a high spatial resolution for estimation and dispersion analysis of vehicular exhaust and non-exhaust PM2.5 emission in an Indian urban-rural landscape. The study indicates that using approaches that do not allocate vehicles kilometers travelled to areas of their expected travel results in underestimating the percent share of PM2.5 emissions from rural roads and motorways while overestimating overall PM2.5 emissions. Particulate matter resuspension is the dominant form of PM2.5 emissions from the vehicular sector on all road types, constituting an even higher fraction on rural roads. Two-wheelers contribute a high fraction of PM2.5 emissions (exhaust and non-exhaust combined), followed by heavy commercial vehicles and four-wheelers on urban roads. Light commercial vehicles, especially agricultural tractors dominate these emissions on rural roads. PM2.5 hotspots are prevalent in urban areas, but several rural areas also experience heavy particulate matter concentrations. Thus, vehicle movement incorporation results in more accurate emission estimation, especially in an urban-rural landscape.

Novel non intrusive continuous use ZeBox technology to trap and kill airborne microbes.

Preventing nosocomial infection is a major unmet need of our times. Existing air decontamination technologies suffer from demerits such as toxicity of exposure, species specificity, noxious gas emission, environment-dependent performance and high power consumption. Here, we present a novel technology called "ZeBox" that transcends the conventional limitations and achieves high microbicidal efficiency. In ZeBox, a non-ionizing electric field extracts naturally charged microbes from flowing air and deposits them on engineered microbicidal surfaces. The surface's three dimensional topography traps the microbes long enough for them to be inactivated. The electric field and chemical surfaces synergistically achieve rapid inactivation of a broad spectrum of microbes. ZeBox achieved near complete kill of airborne microbes in challenge tests (5-9 log reduction) and [Formula: see text] efficiency in a fully functional stem cell research facility in the presence of humans. Thus, ZeBox fulfills the dire need for a real-time, continuous, safe, trap-and-kill air decontamination technology.

Sino-orbital mucormycosis in a COVID-19 patient: A case report.

INTRODUCTION: We report a case of post COVID-19 Sino-orbital Mucormycosis infection caused by Rhizopus oryzae and its management. PRESENTATION OF CASE: The patient was diagnosed with COVID-19 and treated according to the persisting protocols. Following recovery, on the 18th day, the patient developed chemosis and pain in the left eye. A diagnosis of mucormycosis was established after Magnetic Resonance Imaging (MRI) and Functional Endoscopic Sinus Surgery (FESS). Initially, conservative management with intravenous (IV) Fluconazole & Amphotericin B was done and later on with surgical debridement. The patient recovered with minimal residual deformity. DISCUSSION: Mucormycosis generally develops secondary to immunosuppression or debilitating diseases. In Head and Neck cases, the mold usually gains entry through the respiratory tract involving the nose and sinuses, with possible further progression into the orbital and intracranial structures. Hence, an early diagnosis and intervention is required for a good prognosis, decreasing the morbidity. This can be achieved on the basis of clinical picture and direct smears. CONCLUSION: Research needs to be carried out in COVID-19 patients for better prevention and management of opportunistic infections in order to reduce its incidence and morbidity. Prophylactic treatment protocols need to be established, along with rational use of corticosteroids.

Prognostic Value of Serially Estimated Serum Procalcitonin Levels in Traumatic Brain Injury Patients With or Without Extra Cranial Injury on Early In-hospital Mortality: A Longitudinal Observational Study.

BACKGROUND: Traumatic brain injury (TBI) is associated with majority of trauma deaths, and objective tools are required to understand the severity of injury. The application of a biomarker like procalcitonin (PCT) in TBI may allow for assessment of severity and thus aid in prognostication and correlation with mortality and outcome. AIMS: The primary objective is to determine the correlation between PCT concentrations with TBI outcomes (mainly in terms of mortality) at intensive care unit (ICU)/hospital discharge. Secondary objectives are to evaluate correlation with associated extra cranial injuries and complications during hospital stay. METHODS: In total, 186 TBI patients aged > 18 years with minimum survival for at least 12 h admitted to the ICU at the level 1 trauma center were prospectively included in the study and divided into two groups: TBI with and without extra cranial injuries. All admitted patients were treated according to the standard institutional protocol. The PCT levels were obtained on admission, on day 2, and 5. Clinical, laboratory, diagnostic, and therapeutic data were also collected. Primary mortality is defined as death related to central nervous system (CNS) injury, while secondary mortality defined as death related to sepsis or extracranial cause. RESULTS: Median PCT levels at admission, day 2, and day 5 in TBI patients with extracranial injuries were 3.0, 0.83, and 0.69 ng/ml. In total, primary mortality was observed in 18 (9.7%) patients, while secondary causes were attributable in 20 (12.3%) patients. Regression analysis for primarily CNS cause of mortality showed PCT cutoff level at admission more than 5.5 ng/ml carried sensitivity and specificity of 75%, but for secondary cause (sepsis) of mortality, PCT cutoff values on day 2 > 1.15 ng/ml were derived significant with sensitivity of 70% and specificity of 66%. No significant association of parameters like length of ICU stay, Glasgow outcome scale (GOS), and primary/secondary mortality with the presence of extracranial injuries in TBI patients as compared with TBI alone was noted. CONCLUSION: This observational study demonstrates the poor correlation between PCT concentrations with outcome at days 1, 2, and 5 post-injury. The predicted relationship between PCT levels and outcome was not confirmed, and that these results do not support the prognostic utility of PCT biomarker in this population for outcome (mortality) assessment in TBI patients with or without extracranial injuries.

Thermostat-induced spurious interfacial resistance in non-equilibrium molecular dynamics simulations of solid-liquid and solid-solid systems.

Non-equilibrium molecular dynamics (NEMD) simulations universally rely on thermostats to control temperature. The thermostat-induced alteration in the system dynamics that enables temperature control can, however, adversely impact molecular transport across the temperature-controlled and temperature-uncontrolled regions. Here, we analyze the influence of a thermostat on thermal transport across a solid-liquid interface in a canonical setup that, owing to its generality, has been widely employed in NEMD simulations. In scenarios wherein temperature is controlled via stochastic/frictional forcing based thermostats, we find occurrence of a spurious temperature jump across the solid-liquid interface. The corresponding Kapitza length diminishes with a gradual weakening of the coupling between the thermostat and the system. Hence, we identify an optimal thermostat control parameter range over which contrasting requirements of an effective temperature control and a sufficiently low interfacial thermal resistance are simultaneously satisfied. We show that a similar disruption in thermal transport occurs in a single phase system of pure solid atoms as well. We trace the microscopic origin of the anomalous interfacial thermal resistance to a stochastic/frictional forcing-induced alteration in the force autocorrelation function. We propose a simple model consisting of an individual atom impinging in vacuo on a thermostatted solid as a computationally inexpensive alternative for determination of the control parameter range over which thermostat-induced spurious thermal resistance across a solid-liquid interface becomes significant. Our results suggest that the undesirable possibility of MD-deduced temperature jumps being misleading indicators of the interfacial Kapitza resistance could simply be eliminated through a judicious choice of the thermostat control parameter.

Comparison of Effects of Manual and Mechanical Airway Clearance Techniques on Intracranial Pressure in Patients With Severe Traumatic Brain Injury on a Ventilator: Randomized, Crossover Trial.

BACKGROUND: Physical therapist intervention can play a significant role in the prevention of mechanical and infectious complications in patients with traumatic brain injury (TBI) who are mechanically ventilated. OBJECTIVE: The objective of this study was to observe and compare the effects of manual and mechanical airway clearance techniques on intracranial pressure (ICP) and hemodynamics in patients with severe TBI. DESIGN: The design was a prospective, randomized, crossover trial. SETTING: The setting was a neurointensive care unit at a level 1 trauma center. PATIENTS: Forty-six adult patients aged 18 to 75 years, of either sex, with severe TBI, receiving mechanical ventilatory support with continuous ICP monitoring, and undergoing regular airway clearance techniques participated in this study. INTERVENTION: Two techniques were performed by a single trained physical therapist. Treatment A was a manual chest percussion technique and treatment B used a mechanical chest wall vibrator. Each treatment was applied for 10 minutes alternately, separated by an interval of 4 hours. MEASUREMENTS: ICP was measured from the start of intervention to 10 minutes postintervention. Secondary measurements included cerebral perfusion pressure, heart rate, mean arterial pressure (each from the start of the intervention until 10 minutes postintervention at 1-minute intervals), and arterial blood gas parameters (from just before the start of the intervention and 10 minutes postintervention). RESULTS: The increases in mean (95% CI) intracranial pressure of 2.4 (1.4-3.4) and 1.0 (0.2-1.8) mmHg, during and after the intervention with treatment A, respectively, were statistically significantly higher than for treatment B, irrespective of sequence. In contrast, a mean heart rate rise of 6.4 (3.3-9.5) beats/min and mean arterial pressure rise of 5.3 (2.0-8.6) mmHg were significantly higher only during the intervention phase of treatment A compared with treatment B. Peak mean values of ICP, heart rate, and arterial pressure were also significantly higher during treatment A. However, mean values of cerebral perfusion pressure or its degree of change were statistically comparable in both treatment groups. LIMITATIONS: Patients with high baseline ICP values (>20 mmHg) were excluded, and, because of the crossover design, the effect of individual technique on final (long-term) neurological or respiratory outcomes could not be studied. CONCLUSION: Manual chest percussion technique in patients with severe TBI was associated with statistically significant transient increases in ICP and hemodynamics, compared with the mechanical method. However, such transient increases in ICP by either technique were not clinically relevant in patients with moderate-to-severe TBI without intracranial hypertension on a mechanical ventilator.

Role of Preemptive Gabapentin on Postoperative Analgesia After Infraumbilical Surgeries Under Subarachnoid Block-A Randomized, Placebo-Controlled, Double-Blind Study.

BACKGROUND: Preemptive use of gabapentin might accelerate recovery by reducing acute post-inguinal herniorrhaphy pain and opioid requirement being an analgesic. STUDY QUESTION: Assessing efficacy of three different doses of oral gabapentin premedication for postoperative pain management after inguinal herniorrhaphy under spinal anesthesia. STUDY DESIGN: This prospective, randomized, placebo controlled study was performed on 120 male patients (ASA I/II) undergoing inguinal herniorrhaphy under subarachnoid block. Patients were divided into 4 groups of 30 patients each to receive placebo (group A) or gabapentin 400 mg (B) or 800 mg (C) or 1200 mg (D), administered orally 2 hours before surgery. Assessment of postoperative pain was made on the basis of the visual analog score (VAS), where 0 cm "no pain" and 10 cm "worst pain imaginable." Patients received IV fentanyl 0.5 µg/kg bolus when VAS >3. MEASURES AND OUTCOMES: VAS score at regular intervals, the first analgesic requirement and total opioid consumption within 24 hours after surgery along with side/adverse effect (s) of study drug in perioperative period. RESULTS: The VAS of the study groups B, C, D were significantly lower than placebo group (A) at 0, 1, 2, 4, 8, 12, 16, 20, and 24-hour intervals after surgery (P < 0.05). The first analgesic need and total opioid consumption within 24 hours after surgery of study groups were significantly lower than placebo group (P < 0.005) while within study groups difference was not significant. Dizziness and somnolence were seen maximally in group D patients (P = 0.01). However, pruritus, nausea and vomiting though maximally reported among group (A) patients but statistically non-significant. CONCLUSION: Preemptive gabapentin is opioid sparing to control postoperative pain with anxiolysis and sedation. We found the optimal dose to be 400 mg for gabapentin. However, increasing dose from 400 to 1200 mg does not increase its efficacy as analgesic but with higher adverse effects.

New biomarkers in brain trauma.

Brain-specific biomolecules are being increasingly investigated as a viable alternative to the clinical scores and radiological features, on which we still rely upon for stratification, therapy and predicting outcome in traumatic brain injury (TBI). TBI generally leads to release of various chemical compound within the cerebrospinal fluid (CSF) or blood depending on the severity of injury, which were studied variedly in last decades. However, most of these compounds being non-specific to brain, their applicability was challenged further. This review encompasses the novel and promising biomarkers being studied in the present decade, with encouraging results in laboratory and animal or human models.

Early and rapid detection of UCHL1 in the serum of brain-trauma patients: a novel gold nanoparticle-based method for diagnosing the severity of brain injury.

The clinical diagnosis of traumatic brain injury (TBI) is based on neurological examination and neuro-imaging tools such as CT scanning and MRI. However, neurological examination at times may be confounded by consumption of alcohol or drugs and neuroimaging facilities may not be available at all centers. Human ubiquitin C-terminal hydrolase (UCHL1) is a well-accepted serum biomarker for severe TBI and can be used to detect the severity of a head injury. A reliable, rapid, cost effective, bedside and easy to perform method for the detection of UCHL1 is a pre-requisite for wide clinical applications of UCHL1 as a TBI biomarker. We developed a rapid detection method for UCHL1 using surface plasmon resonance of gold nanoparticles with a limit of detection (LOD) of 0.5 ng mL-1. It has a sensitivity and specificity of 100% each and meets an analytical precision similar to that of conventional sandwich ELISA but can be performed rapidly. Using this method we successfully detected UCHL1 in a cohort of 66 patients with TBI and were reliably able to distinguish mild TBI from moderate to severe TBI.

Stuck guidewire due to soft tissue imposition: a rare complication of central line catheter placement.

Central venous catheter (CVC) placement is a commonly done procedure but is associated with a few complications, and guidewire-related complications are one of them. In our case after induction of general anaesthesia, we planned to insert a CVC in the right internal jugular vein under ultrasound guidance. After the insertion of the introducer needle, when we tried to insert the guidewire, it got stuck and was neither moving forward nor in a backward direction. Too much force was not applied to remove the guidewire as it might have caused shearing of the guidewire and further complicated the picture. This problem was solved by simultaneous withdrawal of guidewire along with the needle, and on examination we found soft tissue debris lodged within the lumen which was preventing the guidewire movement in both directions. So, it is suggested that guidewire should be removed along with needle as a single unit if it is required.

Impact of Targeted Preoperative Optimization on Clinical Outcome in Emergency Abdominal Surgeries: A Prospective Randomized Trial.

BACKGROUND: Perforation peritonitis continues to be one of the most common surgical emergencies that need a surgical intervention most of the times. Anesthesiologists are invariably involved in managing such cases efficiently in perioperative period. AIMS: The assessment and evaluation of Acute Physiology and Chronic Health Evaluation II (APACHE II) score at presentation and 24 h after goal-directed optimization, administration of empirical broad-spectrum antibiotics, and definitive source control postoperatively. Outcome assessment in terms of duration of hospital stay and mortality in with or without optimization was also measured. SETTINGS/DESIGN: It is a prospective, randomized, double-blind controlled study in hospital setting. MATERIALS AND METHODS: One hundred and one patients aged ≥18 years, of the American Society of Anesthesiologists physical Status I and II (E) with clinical diagnosis of perforation peritonitis posted for surgery were enrolled. Enrolled patients were randomly divided into two groups. Group A is optimized by goal-directed optimization protocol in the preoperative holding room by anesthesiology residents whereas in Group S, managed by surgery residents in the surgical wards without any fixed algorithm. The assessment of APACHE II score was done as a first step on admission and 24 h postoperatively. Duration of hospital stay and mortality in both the groups were also measured and compared. STATISTICAL ANALYSIS: Categorical data are presented as frequency counts (percent) and compared using the Chi-square or Fisher's exact test. The statistical significance for categorical variables was determined by Chi-square analysis. For continuous variables, a two-sample t-test was applied. RESULTS: The mean APACHE II score on admission in case and control groups was comparable. Significant lowering of serial scores in case group was observed as compared to control group (P = 0.02). There was a significant lowering of mean duration of hospital stay seen in case group (9.8 ± 1.7 days) as compared to control group (P = 0.007). Furthermore, a significant decline in death rate was noted in case group as compared to control group (P = 0.03). CONCLUSION: Goal-directed optimized patients with perforation peritonitis were discharged early as compared to control group with significantly lesser mortality as compared with randomly optimized patients in the perioperative period.

A rare case of malposition of central venous catheter detected by ultrasonography-guided saline flush test.

Central venous catheter (CVC) insertion is associated with many potential complications; malposition of the catheter is one of them. A chest X-ray is routinely done to detect the malposition of catheter, but sometimes it has been seen that X-ray is time-consuming and its accuracy is also low for determining the exact position of the catheter tip. In our case, an ultrasonography (USG)-guided CVC was placed into the right internal jugular vein of the patient. As there was no ECG change obtained during insertion of guidewire and catheter, malposition was suspected, which was easily detected by a novel USG-guided saline flush test. We present a case report where USG was used for detection of a misplaced CVC (from right internal jugular vein to right subclavian vein). With ultrasound, the location of the catheter tip can be confirmed in very less time compared with chest X-ray.