Plasmoid Formation and Strong Radiative Cooling in a Driven Magnetic Reconnection Experiment

We present the first experimental study of plasmoid formation in a magnetic reconnection layer undergoing rapid radiative cooling, a regime relevant to extreme astrophysical plasmas. Two exploding aluminum wire arrays, driven by the Z machine, generate a reconnection layer (S_{L}≈120) in which the cooling rate far exceeds the hydrodynamic transit rate (τ_{hydro}/τ_{cool}>100). The reconnection layer generates a transient burst of >1  keV x-ray emission, consistent with the formation and subsequent rapid cooling of the layer. Time-gated x-ray images show fast-moving (up to 50  km s^{-1}) hotspots in the layer, consistent with the presence of plasmoids in 3D resistive magnetohydrodynamic simulations. X-ray spectroscopy shows that these hotspots generate the majority of Al K-shell emission (around 1.6 keV) prior to the onset of cooling, and exhibit temperatures (170 eV) much greater than that of the plasma inflows and the rest of the reconnection layer, thus providing insight into the generation of high-energy radiation in radiatively cooled reconnection events.

Measurement of energy and directional distribution of neutron ambient dose equivalent for the 7Li(p,n)7Be reaction

Double differential neutron fluence distributions were measured in the 7Li(p,n)7Be reaction for proton beam energies 7, 9 and 12 MeV. Seven liquid scintillator based detectors were employed to measure neutron fluence distributions using the Time of Flight technique. Neutron ambient dose equivalents were determined from the measured fluence distribution using ICRP (International Commission on Radiological Protection) recommended fluence to dose equivalent conversion coefficients. Neutron dose equivalents were also measured using a conventional BF3 detector based REM counter. Ambient dose equivalent measured by the REM counter is found to be in agreement with that determined from the neutron fluence spectra within their uncertainties. Angular distributions of the ambient dose equivalents were also determined from the measured fluence distributions at different angles.

Correlation coefficient between plethysmographic variability index and Systolic Pressure Variation as an indicator for fluid responsiveness in hypotensive patients in the ICU/OT

Background

Prediction of fluid responsiveness in hypotensive patients is a challenge. The correlation between a novel noninvasive dynamic indicator, Pleth Variability Index (PVI ®), and a gold-standard Systolic Pressure Variation (SPV) as a measure of fluid responsiveness was assessed in the Intensive Care Unit (ICU) or Operation Theatre (OT) in a tertiary care hospital.

Methods

A prospective experimental study was conducted over a span of one year on 100 mechanically ventilated patients with hypotension. Vital parameters along with SPV and PVI ® were recorded before and after a standard volume expansion protocol. A 10% SPV threshold was used to define fluid responders and nonresponders.

Results

Pearson's correlation graph at baseline showed positive correlation between PVI ® and SPV (r = 0.59, p-value = 0.001). Strength of correlation was comparatively less but still showed positive correlation at 15 (r = 0.39, p-value = 0.009) and 30 (r = 0.404, p-value = 0.004) minutes of fluid bolus. The Bland Altman analysis of baseline values of PVI ® and SPV showed good agreement with a mean bias of 9.05. Percentage change of PVI ® and SPV over 30 min showed a statistically significant positive correlation in the responder group (r = 0.53, p < 0.05). A threshold value of PVI ® more than 18% before volume expansion differentiated fluid responders and nonresponders with a sensitivity of 75% and specificity of 67%, with an area under Receiver Operating Characteristic (ROC) of 0.78.

Conclusion

A positive correlation exists between SPV and PVI ®, justifying the use of noninvasive PVI ® in a clinical setting of hypotension.

Society of Defence Anaesthesiologists review and recommendations for the provision of anaesthesia for elective dental procedures in various echelons of dental care

Oral diseases are a burden for developing countries such as India where owing to socioeconomic conditions cost is a factor in selecting the type of treatment. Dental care in India is provided at various levels of care including standalone clinics run by individual dental surgeons, multi-speciality dental centres providing specialist care under one roof including paediatric, prosthodontics, and so on and dental centres affiliated with hospitals having facilities for provision of operation theatre and anaesthesia services. Most dental procedures are performed as day-care procedures requiring local anaesthetics, oral, or moderate intravenous sedation and anxiolytics while maxillofacial procedures are carried out in a controlled operation theatre setting. Dental procedures are fraught with risks due to shared oral surgical space and airway leading to reduced field of visibility to dentists especially with the usage of supplementary oxygenation devices, mouth props, and so on. Various dental societies have proposed minimum standards of care for provision of anaesthesia to various dental procedures; however, there are no extant guidelines in our country. The authors propose these guidelines for provision of minimal sedation (anxiolysis) and moderate sedation/analgesia for various day care dental procedures at various levels of care, keeping the aim that no patient’s life is endangered during provision of anaesthesia services at all dental locations.

Compositional modelling of immune response and virus transmission dynamics

Transmission models for infectious diseases are typically formulated in terms of dynamics between individuals or groups with processes such as disease progression or recovery for each individual captured phenomenologically, without reference to underlying biological processes. Furthermore, the construction of these models is often monolithic: they do not allow one to readily modify the processes involved or include the new ones, or to combine models at different scales. We show how to construct a simple model of immune response to a respiratory virus and a model of transmission using an easily modifiable set of rules allowing further refining and merging the two models together. The immune response model reproduces the expected response curve of PCR testing for COVID-19 and implies a long-tailed distribution of infectiousness reflective of individual heterogeneity. This immune response model, when combined with a transmission model, reproduces the previously reported shift in the population distribution of viral loads along an epidemic trajectory. This article is part of the theme issue 'Technical challenges of modelling real-life epidemics and examples of overcoming these'.

Time-resolved velocity and ion sound speed measurements from simultaneous bow shock imaging and inductive probe measurements

We present a technique to measure the time-resolved velocity and ion sound speed in magnetized, supersonic high-energy-density plasmas. We place an inductive ("b-dot") probe in a supersonic pulsed-power-driven plasma flow and measure the magnetic field advected by the plasma. As the magnetic Reynolds number is large (R_M > 10), the plasma flow advects a magnetic field proportional to the current at the load. This enables us to estimate the flow velocity as a function of time from the delay between the current at the load and the signal at the probe. The supersonic flow also generates a hydrodynamic bow shock around the probe, the structure of which depends on the upstream sonic Mach number. By imaging the shock around the probe with a Mach-Zehnder interferometer, we determine the upstream Mach number from the shock Mach angle, which we then use to determine the ion sound speed from the known upstream velocity. We use the sound speed to infer the value of Z̄T_e, where Z̄ is the average ionization and T_e is the electron temperature. We use this diagnostic to measure the time-resolved velocity and sound speed of a supersonic (M_S ∼ 8), super-Alfvénic (M_A ∼ 2) aluminum plasma generated during the ablation stage of an exploding wire array on the Magpie generator (1.4 MA, 250 ns). The velocity and Z̄T_e measurements agree well with the optical Thompson scattering measurements reported in the literature and with 3D resistive magnetohydrodynamic simulations in GORGON.

Concept of BIDI years: Relevance to the perioperative period

Background:

The cumulative effect of cigarette smoking is usually measured by “pack years,” but the same is not present for Bidis. This study was conducted to calculate the concept of “bidi years” in comparison to the concept of “pack-years” for a cigarette

Methods:

Thirty random samples, each of bidis and cigarettes, were selected through a survey of common brands used by smokers in India. The nicotine and carbon monoxide (CO) contents were analyzed by high-pressure liquid chromatography and gas chromatography methods, respectively

Results:

The average nicotine content in thirty samples of different Bidis and Cigarettes was 214.46 ± 57.8 and 616.31 ± 22.6 mg/dL, respectively (P < 0.001). The CO content with a lower mean of 15.57 ± 5.88 was observed in cigarettes as compared to 70.4 ± 22.08 in bidies (P < 0.001). The weight of one cigarette is 0.56 times that of the weight of one bidi. Based on the nicotine content, the equivalent pack years for bidis is calculated as 43 bidis per day per year

Conclusion:

Based on the nicotine content, it is proposed that the equivalent for one cigarette pack-year or 20 cigarette years are taken as 43 bidis per day per year. Even though each bidi stick has an average of 0.46 times the nicotine content of cigarettes, longer abstinence as compared to cigarette is required to bring the nicotine level to normal due to the deeper puffs needed. With the CO content of bidis being 4.5 times that of cigarettes, it is advised that the minimum duration of cessation of smoking before operative procedures be 24 h as compared to 6 h for cigarettes.

Conductivity prediction model for ionic liquids using machine learning

Ionic liquids (ILs) are salts, composed of asymmetric cations and anions, typically existing as liquids at ambient temperatures. They have found widespread applications in energy storage devices, dye-sensitized solar cells, and sensors because of their high ionic conductivity and inherent thermal stability. However, measuring the conductivity of ILs by physical methods is time-consuming and expensive, whereas the use of computational screening and testing methods can be rapid and effective. In this study, we used experimentally measured and published data to construct a deep neural network capable of making rapid and accurate predictions of the conductivity of ILs. The neural network is trained on 406 unique and chemically diverse ILs. This model is one of the most chemically diverse conductivity prediction models to date and improves on previous studies that are constrained by the availability of data, the environmental conditions, or the IL base. Feature engineering techniques were employed to identify key chemo-structural characteristics that correlate positively or negatively with the ionic conductivity. These features are capable of being used as guidelines to design and synthesize new highly conductive ILs. This work shows the potential for machine-learning models to accelerate the rate of identification and testing of tailored, high-conductivity ILs.

The changing face of postgraduate anaesthesia teaching curriculum: Need of the hour!

The speciality of anaesthesiology is evolving rapidly. The recent pandemic witnessed anaesthesiologists as the front-liners catering not only as critical care physicians but also as trainers and even administrators. Today, anaesthesiologists are required to have not just sound clinical knowledge but also proficiency in skills and techniques and aptitude for leadership. The recently introduced competency-based postgraduate training programme for anaesthesiology in India with its specific learning objectives envisages the creation of competent specialists with a broad range of skills who are competent not only to handle effectively medical problems but also acquire the basic teaching skills, communication skills and leadership qualities. The curriculum marks a paradigm shift from university-based, passive, teacher-centric to student-centric, active teaching-learning methods including problem-based and self-directed learning. The mindset, lack of adequately trained faculty, infrastructure, learning resources and time constraints form the major impediment in the successful implementation of the new curriculum.

Association of ischemic electrocardiographic changes in high-altitude areas with coronary angiography

Background

Soldiers native to lowlands, while sojourning at high altitude (HA), are referred to tertiary care centers with electrocardiographic (ECG) abnormalities. Exposure to HA may precipitate myocardial ischemia in subjects with underlying coronary artery disease (CAD). Conversely, it may produce physiological ECG changes mimicking those of CAD, causing a diagnostic dilemma. This study sought to correlate the presence of CAD on coronary angiography (CAG) with a putative diagnosis of CAD based on clinical findings and ECG.

Methods

A prospective study was conducted on patient's from HA areas, referred for evaluation for CAD to a single center at near-sea-level. Thirty-five minimally symptomatic/asymptomatic soldiers with ECG changes suggestive of CAD, underwent CAG. Correlation was sought between ECG and CAG evidence of CAD.

Results

The association of CAD on CAG with clinical and ECG diagnosis of CAD was not significant, 4 of the 35 soldiers (11.4%) showing CAG evidence of CAD (chi square 3.849, p = 0.697). The association between symptoms and coronary artery lesions was, also, not significant, only four of twenty-three (17.4%) minimally symptomatic subjects having CAD on CAG.

Conclusion

Insignificant numbers of previously healthy persons, who present with minimal symptoms and ECG changes suggestive of CAD while sojourning at HA, have coronary artery involvement on CAG. Those with incidental ECG changes, without symptomatology, do not have CAD on CAG.

Optimal management of brain-dead organ donor

Maintaining a brain stem-dead (BSD) donor is specialized science. It is a daunting task as they are fragile patients who need to be handled with utmost care owing to extreme haemodynamically instability and need the best of monitoring for maintenance of organs. To ensure a successful transplant, a BSD donor first needs to be identified on time. This requires scrupulous monitoring of neurologically compromised patients who tend to be the most frequent organ donors. Once the donor is identified, an all-out effort should be made to legally obtain consent for the donation. This may require numerous sessions of counselling of the relatives. It needs to be performed tactfully, displaying the best of intentions. It is important to understand the physiology of a brain-dead individual. A cascade of changes occurs in BSD donor which result in a catastrophic plummeting of the clinical condition of the donor. All organ systems are involved in this clinical chaos, and best possible clinical support of all organ systems should be available and extended to the donor. Organ support includes cardiovascular, pulmonary, temperature, glycaemic, metabolic and hormonal. This article has been written as a follow-up article of previously published article on identifying an organ donor. It intends to give the reader a concept of what the BSD donor undergoes after brain death and as to how to maintain and preserve various organs for donation for successful transplantation of maximum organs.

A Rare Case of Epileptic Seizure After-effect Resulting in Nontraumatic Spontaneous Subdural Hemorrhage

Generalized tonic-clonic seizures (GTCS) result in diverse physiological alterations that are mostly short-lived and rarely lead to immediate serious consequences. Some early serious complications reported are head trauma and aspiration. While most cases of seizures are diagnosed readily from clinical history, some cases remain indolent and present later. A brain hemorrhage can have varied manifestations that warrant every clinician to be vigilant in diagnosis and management to prevent life-threatening complications. Furthermore, many reports have described seizures in patients operated for subdural hematoma (SDH), but to the best of our knowledge, none reveals SDH after the seizure. We encountered an unexpected incident of severe SDH in a 32-year-old adult following witnessed GTCS.

How to cite this article

Singh S, Kaushal A, Datta R, Unnithan RR, Mishra N. A Rare Case of Epileptic Seizure After-effect Resulting in Nontraumatic Spontaneous Subdural Hemorrhage. Indian J Crit Care Med 2020;24(8):722-723.

COVID-2019: Experience of setting up quarantine center

Indians stranded in countries reporting widespread transmission of COVID-19 in Jan to Mar 2020 were evacuated at short notice. Unclear and evolving evidence on COVID-19, risk of transmission of the disease from pre-symptomatic, asymptomatic and known cases of COVID-19 has put the spotlight back on the practice of quarantine. The article describes the processes, inter-sectoral coordination and methodology adopted for putting in place all measures for a successful evacuation and subsequent quarantine of the evacuees at the first Quarantine camp set up in India at Manesar, Gurugram near New Delhi by the Armed Forces. No health care worker or support staff contracted any infection with SARS-Cov-2 during the period of care and contact with those quarantined. The archaic practice of quarantine has yet again proven to be a robust and effective Public Health tool with great relevance in the ongoing Pandemic of COVID-19.

A fluoroscopic assessment of brachial plexus block by the supraclavicular approach: Have we been overmedicating?

Background

Ultrasonography-guided supraclavicular brachial plexus block has demonstrated safety as compared with landmark or nerve stimulation techniques. However, the minimum effective analgesic volume (MEAV) necessary for adequate blockade has not been determined. This study was undertaken to assess under fluoroscopy the postinjection spread of different drug volumes with clinical correlation. Secondary outcome measures included correlation of onset of block, block quality, and incidence of side effects.

Methods

This randomized, multiarm, cross-sectional, observational study was conducted at a single tertiary care center. A total of 549 patients were randomly allocated to 3 groups (20 ml, 30 ml, and 40 ml of drug mixture). A local anesthetic drug mixture with a radiopaque dye was administered under ultrasonographic guidance, and postinjection fluoroscopic drug spread was studied.

Results

Surgical anesthesia was achieved in 494 (89.98%) patients with 85.25%, 92.97%, and 91.71% in 20-, 30-, and 40-ml groups, respectively, being significantly low (p = 0.0317) in the 20-mL group. Cephalad and infraclavicular spread was higher in the 40-mL group than in other two groups (p = 0.103). Horner syndrome (HS) was seen in 51.18% of patients. First, ipsilateral superficial cervical plexus block was also observed in 40.22% of patients. Among patients who developed both, ∼60% of patients (99/167) belonged to the 40-mL group.

Conclusions

Optimal MEAV appears between 20 and 30 mL. Higher drug volumes are associated with more cephalad spread and side effects. Drug spread can predict block efficacy as well. It is postulated that loss of sensation in the ipsilateral neck can be used to predict development of hemidiaphragmatic paresis similar to HS.

Sub-Kelvin cooling for two kilopixel bolometer arrays in the PIPER receiver

The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne telescope mission to search for inflationary gravitational waves from the early universe. PIPER employs two 32 × 40 arrays of superconducting transition-edge sensors, which operate at 100 mK. An open bucket Dewar of liquid helium maintains the receiver and telescope optics at 1.7 K. We describe the thermal design of the receiver and sub-Kelvin cooling with a continuous adiabatic demagnetization refrigerator (CADR). The CADR operates between 70 and 130 mK and provides ≈10 μW cooling power at 100 mK, nearly five times the loading of the two detector assemblies. We describe electronics and software to robustly control the CADR, overall CADR performance in flightlike integrated receiver testing, and practical considerations for implementation in the balloon float environment.

Exploration of insecticidal potential of an alpha glucosidase enzyme inhibitor from an endophytic Exophiala spinifera

AIM

The present study aimed to isolate and screen endophytes from Trachyspermum ammi with the ability to inhibit alpha glucosidase enzyme and evaluate their insecticidal potential.

METHODS AND RESULTS

Endophytic fungi isolated from T. ammi were screened for alpha glucosidase inhibitory activity. Maximum inhibition (96%) was observed in an isolate AZ-9, identified to be Exophiala spinifera on morphological and molecular basis. Production of fungal metabolites was carried out in malt extract broth followed by extraction with ethyl acetate. Brown coloured gummy residue obtained after evaporation of ethyl acetate was partially soluble in water yielding white precipitates. The precipitate exhibiting α-glucosidase inhibitory activity was purified by repeated washing and centrifugation. The insecticidal activity of inhibitor was evaluated on Spodoptera litura (Fab.) by feeding this pest on diet amended with inhibitor. It resulted in significant larval mortality as well as deformities in emerging adults. A reduction in vivo digestive enzyme activity was also observed. Nutritional analysis revealed the toxic effect of AZ-9 inhibitor on various food utilization parameters of S. litura. A significant reduction was recorded in relative growth and consumption rate of S. litura.

CONCLUSIONS

This is the first report on production of an alpha glucosidase inhibitor from E. spinifera with insecticidal activity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study highlights the importance of endophytes in providing protection against insect pests to the host. It also suggests the insecticidal potential of alpha glucosidase inhibitor from E. spinifera against polyphagous pest S. litura.

Removal of prometryn from hydroponic media using marsh pennywort (Hydrocotyle vulgaris L.)

The aquatic plant Hydrocotyle vulgaris was evaluated for its efficacy in removing prometryn from nutrient solution. Under optimized experimental conditions, up to 94.0% of the initial prometryn was removed from the hydroponic culture medium by H. vulgaris in 30 days. The concentration of prometryn decreased from the initial level of 0.55 ± 0.013 mg/L to 0.036 ± 0.001 mg/L at the end of the experimental period. The removal kinetics followed first-order kinetic equation (Ct = 0.4569e^-0.09t). Half-life (t_1/2) of prometryn was greatly shortened from 27.16 days (without plant) to 5.58 days (with H. vulgaris). Approximately 22% of the initial prometryn residue was found in H. vulgaris tissue, while 11.7% was degraded by the plant in 30 days. The metabolites of prometryn detected were 2,4-diamino-1,3,5-triazine (in the hydroponic culture medium) and 2,4,6-trihydroxy-1,3,5-triazine (in plant tissue) after 30 days. The results indicate that H. vulgaris can be used for phytoextraction of prometryn and could potentially be effective in removing other s-trazine pesticides from contaminated aquatic ecosystems.

Recurrent Metabolic Acidosis during High-dose Midazolam Therapy for Refractory Status Epilepticus

High-dose continuous midazolam therapy has been used successfully for control of refractory status epilepticus. However, normal anion gap (AG) metabolic acidosis, a deleterious complication of this therapy is underrecognized. Even though previously reported in an isolated case report in a pediatric patient, we observed similar complication in an adult patient. Stereotyped normal AG metabolic acidosis along with hypotension developed on two occasions during high-dose continuous midazolam hydrochloride infusion that reverted rapidly following cessation of the infusion.

Arctic cut-off high drives the poleward shift of a new Greenland melting record

Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700±50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948–2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade.

Atmospheric circulation controls the mass and energy balance of the Greenland ice sheet, yet the exact dynamics remain unknown. Here, the authors show that record conditions over Greenland during the summer of 2015 were associated with the formation and persistency of an Arctic cut-off high.

Uptake of 2,4-bis(Isopropylamino)-6-methylthio-s-triazine by Vetiver Grass (Chrysopogon zizanioides L.) from Hydroponic Media

2,4-bis(Isopropylamino)-6-methylthio-s-triazine (prometryn) poses a risk to aquatic environments in several countries, including China, where its use is widespread, particularly due to its chemical stability and biological toxicity. Vetiver grass (Chrysopogon zizanioides L.) was tested for its potential for phytoremediation of prometryn. Vetiver grass was grown in hydroponic media in a greenhouse, in the presence of prometryn, with appropriate controls. Plant uptake and removal of prometryn from the media were monitored for a period of 67 days. The results showed that the removal of the prometryn in the media was expedited by vetiver grass. The removal half-life (t1/2) was shortened by 11.5 days. Prometryn removal followed first-order kinetics (Ct = 1.8070e(-0.0601t)). This study demonstrated the potential of vetiver grass for the phytoremediation for prometryn.

Hydroxyeyhyl starch: Controversies revisited

Hydroxyethyl starch (HES) family has been one of the cornerstones in fluid management for over four decades. Recent evidence from clinical studies and meta-analyses has raised few concerns about the safety of these fluids, especially in certain subpopulations of patients. High-quality clinical trials and meta-analyses have emphasized nephrotoxic effects, increased risk of bleeding, and a trend toward higher mortality in these patients after the use of HES solutions. Scientific evidence was derived from international guidelines, aggregated research literature, and opinion-based evidence was obtained from surveys and other activities (e.g., internet postings). On critical analysis of the current data available, it can be summarized that further large scale trials are still indicated before HES can be discarded.

Large-aperture wide-bandwidth antireflection-coated silicon lenses for millimeter wavelengths

The increasing scale of cryogenic detector arrays for submillimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n=3.4, low loss, and high thermal conductivity is a nearly optimal material for these purposes but requires an antireflection (AR) coating with broad bandwidth, low loss, low reflectance, and a matched coefficient of thermal expansion. We present an AR coating for curved silicon optics comprised of subwavelength features cut into the lens surface with a custom three-axis silicon dicing saw. These features constitute a metamaterial that behaves as a simple dielectric coating. We have fabricated silicon lenses as large as 33.4 cm in diameter with micromachined layers optimized for use between 125 and 165 GHz. Our design reduces average reflections to a few tenths of a percent for angles of incidence up to 30° with low cross polarization. We describe the design, tolerance, manufacture, and measurements of these coatings and present measurements of the optical properties of silicon at millimeter wavelengths at cryogenic and room temperatures. This coating and lens fabrication approach is applicable from centimeter to submillimeter wavelengths and can be used to fabricate coatings with greater than octave bandwidth.

A prospective review of the labor analgesia programme in a teaching hospital

BACKGROUND

The structured labor analgesia programme in our tertiary care hospital has been in place for the past few years. We undertook this study to analyze the programme and to draw conclusions to further improve the outcomes.

METHODS

A prospective analysis of the data pertaining to 200 patients participating in an ongoing labor analgesia programme in a tertiary care hospital from Nov 2008 to Aug 2009 was performed.

RESULTS

Mean visual analog score (VAS) before epidural block was 8.34 ± 0.79. Post procedure the average VAS score was 2.20 ± 0.79. One hundred and fifty six (78%) parturients delivered vaginally, 18 (9%) required instrumentation with vacuum including 1 forceps delivery in a multiparous parturient. In 17parturients (8.7%) fetal distress led to a decision to perform LSCS for delivery. Multiparous patients were significantly more satisfied as compared to nulliparous patients (p = 0.010).

CONCLUSION

The study demonstrated excellent pain relief and patient satisfaction with minimal complications. The safety and efficacy of epidural bupivacaine in concentrations less than 0.625% combined with 25 mcg of fentanyl demonstrated in our study should be considered are commendation for the widespread adoption of the procedure in tertiary care hospitals.

OVERCOMING INCOMPATIBILITY PROBLEMS IN ELASTOMER BLENDS BY TAILORED SURFACE PROPERTIES OF RUBBER ADDITIVES

Rubber is a challenging composite material, whose functionality strongly depends on the affinity of the different materials in the composite and its morphology. One way to tailor polarity and chemistry of the filler surface is plasma coating. When using acetylene, thiophene, or pyrrole as monomers, the coating results in a reduced polarity of the filler compared with untreated silica, and unsaturated C–C bonds are formed on the surface. This improves the compatibility of the filler–polymer blends. In a SBR/EPDM blend, the filler–polymer compatibility is improved for all plasma-coated fillers compared with untreated silica. The best dispersion is achieved by plasma–pyrrole coating, as measured by the Payne effect and reinforcement parameter. The rubber–filler interaction is also highest for this blend, as measured by the bound rubber content. As expected, this results in improved tensile properties. In NBR/EPDM, the filler–filler interaction is significantly reduced by the plasma–pyrrole coating, which indicates a balanced compatibility of the pyrrole-treated silica in both polymers. The properties of the vulcanizate show the combinatorial effect of dispersion, filler–polymer interaction, polymer entanglements, and cross-link density. All plasma-treated, silica-filled NBR/EPDM materials show a considerable increase in tensile strength compared with untreated silica, with polyacetylene-treated silica resulting in the best properties. When plasma-coated curatives are used in SBR/EPDM blends, the scorch safety of the compounds is increased and the rupture energy is enhanced. In NBR/EPDM blends, all packages of the modified curatives provide an increased maximum torque compared with the control. Mechanical properties of the NBR/EPDM blend are improved even more than they are with SBR/EPDM. This indicates a more-balanced distribution of cross-links, along with a more-homogeneous carbon black dispersion over the different rubber phases. A better polarity match between additives and polymers usually results in improved material properties. The wide variety of monomers for the plasma polymerization allows researchers to tailor the surface properties of the additives.

End of life issues in the intensive care units

A structured discussion of End-of-Life (EOL) issues is a relatively new phenomenon in India. Personal beliefs, cultural and religious influences, peer, family and societal pressures affect EOL decisions. Indian law does not provide sanction to contentious issues such as do-not-resuscitate (DNR) orders, living wills, and euthanasia. Finally, published data on EOL decisions in Indian ICUs is lacking. What is needed is a prospective determination of which patients will benefit from aggressive management and life-support. A consensus regarding the concept of Medical Futility is necessary to give impetus to further discussion on more advanced policies including ideas such as Managed Care to restrict unnecessary health care costs, euthanasia, the principle of withhold and/or withdraw, ethical and moral guidelines that would govern decisions regarding futile treatment, informed consent to EOL decisions and do-not-resuscitate orders. This review examines the above concepts as practiced worldwide and looks at some landmark judgments that have shaped current Indian policy, as well as raising talking points for possible legislative intervention in the field.