Comparison of APACHE II and APACHE IV score as predictors of mortality in patients with septic shock in intensive care unit: A prospective observational study.

Background and Aims: Prediction of outcome in intensive care unit (ICU) patients is of imperative importance. Our aim was to assess and compare the performance of Acute Physiology and Chronic Health Evaluation (APACHE) II and APACHE IV scores in predicting mortality in adult patients suffering from septic shock admitted to our ICU. Material and Methods: This was a prospective observational study conducted in a 14-bedded medical ICU of a tertiary care center from January 2019 to March 2020; 128 patients suffering from septic shock were included and APACHE II and IV scores were calculated. We also calculated the predicted and actual mortality rates and standardized mortality ratios. The receiver operating characteristic curves were used to assess discrimination. Results: Out of the 128 patients, 63 patients (49.21%) died. The mean (± standard deviation) admission APACHE II score was 16.7 ± 5.53, while the mean APACHE IV score was 67.25 ± 25.99. The non-survivors had significantly higher APACHE II and IV scores when compared to those who survived (P < 0.001). APACHE II had a slightly better discriminative power (with the area under the Receiver operating characteristic (ROC) curve of 0.78) than APACHE IV (with the area under the ROC curve of 0.74). The mean predicted mortality rate (PMR) of the patient population calculated on the basis of the APACHE II scoring system was 22.46 ± 15.76, and the mean PMR calculated as per the APACHE IV scoring system was 11.64 ± 15.59. Conclusion: Both APACHE II and APACHE IV underestimated mortality in septic shock patients. Both APACHE II and APACHE IV were comparable in differentiating survivors from non-survivors. However, there was a good correlation between the two models.

Contrastive Representation Learning for Gaze Estimation.

Self-supervised learning (SSL) has become prevalent for learning representations in computer vision. Notably, SSL exploits contrastive learning to encourage visual representations to be invariant under various image transformations. The task of gaze estimation, on the other hand, demands not just invariance to various appearances but also equivariance to the geometric transformations. In this work, we propose a simple contrastive representation learning framework for gaze estimation, named Gaze Contrastive Learning (GazeCLR). GazeCLR exploits multi-view data to promote equivariance and relies on selected data augmentation techniques that do not alter gaze directions for invariance learning. Our experiments demonstrate the effectiveness of GazeCLR for several settings of the gaze estimation task. Particularly, our results show that GazeCLR improves the performance of cross-domain gaze estimation and yields as high as 17.2% relative improvement. Moreover, the GazeCLR framework is competitive with state-of-the-art representation learning methods for few-shot evaluation. The code and pre-trained models are available at https://github.com/jswati31/gazeclr.

Assessment of residual gastric volume using point-of-care ultrasonography in adult patients who underwent elective surgery.

BACKGROUND: Aspiration pneumonitis remains a dreaded complication that may lead to almost 9% of anaesthesia-related deaths. The presence of gastric contents has always been a contributing factor to an increased risk of aspiration. Preoperative gastric ultrasound has been suggested as a modality for determining residual volume in special populations and conditions. We conducted an observational study to determine the gastric residual volume in preoperative patients of elective surgery with gastric ultrasound and to study its correlation with patient factors. METHODS: We enrolled 411 patients in the age group of 18-80 with ASA-PS I and II having BMI less than 35 kg/m2. Patients with prior gastrointestinal surgery and parturients were excluded from the present study. Gastric antrum in both supine and right lateral decubitus positions was measured using USG in the immediate preoperative period, and gastric residual volume was calculated, which was subsequently correlated with various patient factors. RESULTS: On qualitative assessment, 97 and 118 patients were observed to have distended stomachs in the supine and right lateral decubitus positions, respectively. On quantitative assessment, 336 had safe GRV, 60 patients were classified as having a low risk of aspiration (GRV < 1.5 ml/kg) while 13 had a high risk of aspiration (> 1.5 ml/kg). Eight patients with a fasting duration of more than ten hours and five who fasted between 6 and 10 h had a gastric residual volume of more than 1.5 ml/h. Patients who were premedicated with histamine blockers had a statistically significant higher antral cross-sectional area (p-value - 0.022*) and GRV (p-value - 0.018*) in the right lateral decubitus position compared to patients who had taken proton pump inhibitors (PPIs). As BMI increased, there was a statistically significant (p-value < 0.001) increase in mean antral CSA in both supine and right lateral decubitus positions. There was a statistically significant association found between type 2 diabetes (p-value 0.045*) with antral grade. DISCUSSION: Patients can have significant residual volume (> 1.5 ml/kg) despite adequate fasting, and preoperative gastric ultrasound can help in assessing the same and guiding perioperative airway management. PPIs are more effective in reducing gastric residual volume as compared to histamine blockers. Patients with a BMI of more than 30 and type 2 diabetes mellitus have significant correlation with increased gastric residual volume mandating preoperative gastric ultrasound assessment for effective management. CONCLUSIONS: Patients with BMI over 30 and type 2 diabetes may benefit from POCGUS to guide perioperative airway management by stratifying GRV. Trial registration Name of registry-Clinical Trial Registry of India. Trial registration number-2020/03/024083. Date of registration-19.3.2020. URL- http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=39961&EncHid=&userName=.

Awake videolaryngoscopic orotracheal intubation in patients with laryngeal tumour using the C-MAC D-Blade.

Background and Aims: This study assessed the applicability of C-MAC videolaryngoscope (VL) D-blade for awake intubation in patients with laryngeal tumour. The primary study objective was to determine the rate of successful intubation in the first attempt. The other parameters recorded were number of attempts required for intubation, duration of different stages of intubation, haemodynamics, ease of intubation and patient comfort on visual analogue scale (VAS) postoperatively. Methods: Thirty patients were studied. Patients were sedated with dexmedetomidine and fentanyl as a slow bolus (over 20 min) and Ramsay sedation score was assessed. Topicalisation of the oropharynx, tonsillar pillars and base of the tongue was done with lignocaine 10% spray. Four ml of 4% lignocaine using MADgic atomiser was used for anaesthetising the glottis and the tracheal lumen. Results: Successful intubation was achieved in 86.6% patients in first attempt and 13.3% in two attempts. Total time for all intubations was less than 30 seconds. Fremantle score was F-1-C-MAC D-blade (easy intubation with full view) in 60% patients, while 23.3% had F-2-C-MAC D-blade (full view and either required more than one attempt or a modified technique), 13.3% had P-1-C-MAC D-blade (partial view with easy intubation) and 3.3% had P-2-C-MAC D-blade (partial view and required more than one attempt or a modified technique). The VAS score for anaesthesiologist's ease and for patient's experience was 85.83 ± 7.20 and 86.66 ± 14.46, respectively. Conclusion: C-MAC VL D-blade-assisted awake intubation is an effective and safe method to manage the airway of patients with laryngeal tumour once adequate topicalisation is ensured before the procedure.

Topical vs. intravenous administration of tranexamic acid to minimize blood loss in abdominal hysterectomy perioperatively: A randomized controlled study.

Background and Aims: Topical application of tranexamic acid (TXA) to bleeding wound surfaces is rapidly gaining recognition and currently a topic of further research in patients undergoing abdominal hysterectomy. The aim of the study was to compare the efficacy of topical vs. intravenous (i.v.) administration of TXA in reducing perioperative blood loss in patients undergoing abdominal hysterectomy. Material and Methods: A double-blinded parallel-group randomized controlled study was conducted in a tertiary teaching institute. Group 1 (n = 25) received 10 mg.kg-1 i.v. bolus of TXA after induction followed by infusion of 1 mg.kg-1.h-1 of TXA, in 50 ml of normal saline (NS), till the completion of surgery and just before closure of peritoneum 100 ml of NS was applied topically over the raw surface. Group 2 (n = 25) received 50 ml of NS over 10 min after induction, followed by infusion of 50 ml of NS, till the completion of surgery and just before closure of peritoneum, 1.5 g of TXA mixed in 100 ml of NS was applied topically over the raw surface. The primary outcome was total perioperative blood loss (intraoperative plus 24 h postoperative). The secondary outcomes included change in hemoglobin concentration postoperatively at 12 h, 24 h; need for blood/blood product transfusion; amount of blood/blood product transfused and side effects of TXA. Results: Total perioperative blood loss was 312 ± 106.65 ml in group 1 and 325 ± 89.90 ml in group 2 (p = 0.659). It was found that the mean reduction in hemoglobin was 0.7 g.dl-1 and 0.54 g.dl-1 in group 1 and 0.67 g.dl-1 and 0.44 g.dl-1 in group 2 at 12 h and 24 h respectively, with no significant intergroup difference. Conclusion: Administration of TXA topically is as efficacious as TXA administered i.v. to minimize perioperative blood loss in patients undergoing abdominal hysterectomy.

Tracker/Camera Calibration for Accurate Automatic Gaze Annotation of Images and Videos.

Modern appearance-based gaze tracking algorithms require vast amounts of training data, with images of a viewer annotated with "ground truth" gaze direction. The standard approach to obtain gaze annotations is to ask subjects to fixate at specific known locations, then use a head model to determine the location of "origin of gaze". We propose using an IR gaze tracker to generate gaze annotations in natural settings that do not require the fixation of target points. This requires prior geometric calibration of the IR gaze tracker with the camera, such that the data produced by the IR tracker can be expressed in the camera's reference frame. This contribution introduces a simple tracker/camera calibration procedure based on the PnP algorithm and demonstrates its use to obtain a full characterization of gaze direction that can be used for ground truth annotation.

Rethinking Model-Based Gaze Estimation.

Over the past several years, a number of data-driven gaze tracking algorithms have been proposed, which have been shown to outperform classic model-based methods in terms of gaze direction accuracy. These algorithms leverage the recent development of sophisticated CNN architectures, as well as the availability of large gaze datasets captured under various conditions. One shortcoming of black-box, end-to-end methods, though, is that any unexpected behaviors are difficult to explain. In addition, there is always the risk that a system trained with a certain dataset may not perform well when tested on data from a different source (the "domain gap" problem.) In this work, we propose a novel method to embed eye geometry information in an end-to-end gaze estimation network by means of a "geometric layer". Our experimental results show that our system outperforms other state-of-the-art methods in cross-dataset evaluation, while producing competitive performance over within dataset tests. In addition, the proposed system is able to extrapolate gaze angles outside the range of those considered in the training data.

A real time face mask detection system using convolutional neural network.

In current times, after the rapid expansion and spread of the COVID-19 outbreak globally, people have experienced severe disruption to their daily lives. One idea to manage the outbreak is to enforce people wear a face mask in public places. Therefore, automated and efficient face detection methods are essential for such enforcement. In this paper, a face mask detection model for static and real time videos has been presented which classifies the images as "with mask" and "without mask". The model is trained and evaluated using the Kaggle data-set. The gathered data-set comprises approximately about 4,000 pictures and attained a performance accuracy rate of 98%. The proposed model is computationally efficient and precise as compared to DenseNet-121, MobileNet-V2, VGG-19, and Inception-V3. This work can be utilized as a digitized scanning tool in schools, hospitals, banks, and airports, and many other public or commercial locations.

Zwitterionic Luminescent 2D Metal-Organic Framework Nanosheets (LMONs): Selective Turn-On Fluorescence Sensing of Dihydrogen Phosphate.

While a plethora of organic linkers based on carboxylic acids have been utilized in the construction of MOFs, zwitterionic linkers that typify the attributes of naturally occurring amino acids have been exploited only scarcely to the best of our knowledge. Zwitterionic interior characteristics should be expected to impart unique properties to the resultant MOFs with a high potential to interact with guest species through electrostatic interactions. In our investigations with bis(p-carboxyphenyl)imidazolylarenes as a novel class of linkers for the development of functional MOFs, we have found that bisimidazole-tetracarboxylic acid H4DMBI undergoes metal-assisted self-assembly with Zn(NO3)2 to yield a layered MOF (Zn-DMBI). In the latter, the linker serves as a two-connecting linker with imidazoles and carboxylic acids behaving as zwitterions. The layers are offset stacked in the crystal structure and are bound firmly by hydrogen bonds between imidazolium and carboxylate ions. Such a packing precludes fluorescence from being observed due to self-quenching. However, exfoliation into zwitterionic 2D metal-organic nanosheets (MONs) by sonication in methanol for 1 h liberates palpable fluorescence. Furthermore, the suspension of luminescent MONs (LMONs) in methanol permits selective sensing of anions; in particular, dihydrogen phosphate (H2PO4-) that is complementary to the zwitterions in terms of hydrogen bond donor and acceptor sites is observed with fluorescence enhancement by 120%, leading to its detection at a sub-parts-per-million (0.13 ppm) level. Thus, access to zwitterionic 2D MONs and their application for selective anion sensing with "turn-on" fluorescence are demonstrated by a rational de novo bottom-up approach.

Contrasting Photochromic and Acidochromic Behaviors of Pyridyl- and Pyrimidylethynylated Mono- and Bis-Benzopyrans.

Investigation of photochromic and acidochromic behaviors of a set of pyridyl- and pyrimidylethynylated mono- and bis-benzopyrans reveals an intriguing influence of the N-heteroaryl ring on spectrokinetic properties of the photogenerated o-quinonoid colored reactive intermediates. While the absorption maxima of the pyridylethynylated bis-benzopyran and its photogenerated o-quinonoid colored species undergo bathochromic shifts by ca. 40 and 22 nm, respectively, in the presence of an acid (e.g., trifluoroacetic acid (TFA)), the same remain unaffected for the analogous pyrimidylethynylated bis-benzopyran and its photogenerated o-quinonoid colored species under similar conditions. Modification of the photochromic behavior of these benzopyrans and, hence, spectrokinetic properties of their photogenerated o-quinonoid species in the presence of H+ is a consequence of relative proton affinities of N-heteroaryl rings, i.e., pyridyl/pyrimidyl, and the resonance effects relayed through the ethynyl spacers in a push-pull π-delocalized-type skeleton; the mesomeric effects operate in a contrasting manner depending on the N-heteroaryl ring in the absence and in the presence of an acid. These molecular systems offer a unique opportunity to modulate both photochromic and acidochromic properties of benzopyrans and their photogenerated colored o-quinonoid intermediates by leveraging N-heteroaromatic rings.

Additively manufactured BaTiO3 composite scaffolds: A novel strategy for load bearing bone tissue engineering applications.

Piezoelectric ceramics, such as BaTiO3, have gained considerable attention in bone tissue engineering applications thanks to their biocompatibility, ability to sustain a charged surface as well as improve bone cells' adhesion and proliferation. However, the poor processability and brittleness of these materials hinder the fabrication of three-dimensional scaffolds for load bearing tissue engineering applications. For the first time, this study focused on the fabrication and characterisation of BaTiO3 composite scaffolds by using a multi-material 3D printing technology. Polycaprolactone (PCL) was selected and used as dispersion phase for its low melting point, easy processability and wide adoption in bone tissue engineering. The proposed single-step extrusion-based strategy enabled a faster and solvent-free process, where raw materials in powder forms were mechanically mixed and subsequently fed into the 3D printing system for further processing. PCL, PCL/hydroxyapatite and PCL/BaTiO3 composite scaffolds were successfully produced with high level of consistency and an inner architecture made of seamlessly integrated layers. The inclusion of BaTiO3 ceramic particles (10% wt.) significantly improved the mechanical performance of the scaffolds (54 ± 0.5 MPa) compared to PCL/hydroxyapatite scaffolds (40.4 ± 0.1 MPa); moreover, the presence of BaTiO3 increased the dielectric permittivity over the entire frequency spectrum and tested temperatures. Human osteoblasts Saos-2 were seeded on scaffolds and cellular adhesion, proliferation, differentiation and deposition of bone-like extracellular matrix were evaluated. All tested scaffolds (PCL, PCL/hydroxyapatite and PCL/BaTiO3) supported cell growth and viability, preserving the characteristic cellular osteoblastic phenotype morphology, with PCL/BaTiO3 composite scaffolds exhibiting higher mineralisation (ALP activity) and deposited bone-like extracellular matrix (osteocalcin and collagen I). The single-step multi-material additive manufacturing technology used for the fabrication of electroactive PCL/BaTiO3 composite scaffolds holds great promise for sustainability (reduced material waste and manufacturing costs) and it importantly suggests PCL/BaTiO3 scaffolds as promising candidates for load bearing bone tissue engineering applications to solve unmet clinical needs.

3D printed PEEK/HA composites for bone tissue engineering applications: Effect of material formulation on mechanical performance and bioactive potential.

Polyetheretherketone (PEEK) is a biocompatible polymer widely used for biomedical applications. Because it is biologically inert, bioactive phases, such as nano-hydroxyapatite (HA), have been added to PEEK in order to improve its bioactivity. 3D printing (3DP) technologies are being increasingly used today to manufacture patient specific devices and implants. However, processing of PEEK is challenging due to its high melting point which is above 340 °C. In this study, PEEK-based filaments containing 10 wt% of pure nano-HA, strontium (Sr)- doped nano-HA and Zinc (Zn)-doped nano-HA were produced via hot-melt extrusion and subsequently 3D printed via fused deposition modelling (FDM), following an initial optimization process. The raw materials, extruded filaments and 3D printed samples were characterized in terms of physicochemical, thermal and morphological analysis. Moreover, the mechanical performance of 3D printed specimens was assessed via tensile tensing. Although an increase in the melting point and a reduction in crystallization temperature was observed with the addition of HA and doped HA to pure PEEK, there was no noticeable increase in the degree of crystallinity. Regarding the mechanical behavior, no significant differences were detected following the addition of the inorganic phases to the polymeric matrix, although a small reduction in the ultimate tensile strength (~14%) and Young's modulus (~5%) in PEEK/HA was observed in comparison to pure PEEK. Moreover, in vitro bioactivity of 3D printed samples was evaluated via a simulated body fluid immersion test for up to 28 days; the formation of apatite was observed on the surfaces of sample surfaces containing HA, SrHA and ZnHA. These results indicate the potential to produce bioactive, 3DP PEEK composites for challenging applications such as in craniofacial bone repair.

Mechanoluminescence and aggregation-enhanced emission (AEE) of an In-MOF based on a 9,9'-diphenyl-9H-fluorene tetraacid linker.

A water-stable In-MOF, constructed based on a conformationally-flexible tetraacid linker, i.e., 2,7-bis(3,5-dicarboxyphenyl)-9,9'-diphenyl-9H-fluorene, i.e., H4DPF, is shown to exhibit a significantly enhanced solid-state fluorescence quantum yield (φf) of 23% in comparison with that of the linker (φfca. 4%) as a consequence of rigidification of the latter by metalation. Application of external stimulus in the form of grinding of the In-MOF leads to a drastic enhancement by 29%, φf from 23 to 52%. Solid-state absorption and emission spectra show that the absorption in the region of 368-550 nm gets diminished with a concomitant change in the emission maximum with a blue shift upon grinding. Fluorescence enhancement with grinding is correlated with a gradual reduction in the size of the particles, as established by SEM analysis. MOF particle aggregation has been invoked to account for the observed fluorescence enhancement in addition to a subtle conformational change in the structure of the linker upon grinding. Intriguingly, the ground MOF particles exhibit aggregation behaviour in the DMF-water solvent system with the emission further increasing up to 75% for the increase in the water fraction (fw) from 0 to 60%; hydrophobic aggregation of particles evidently leads to a change in the conformation of the linker and particle aggregation-enhanced emission (AEE). De-aggregation of particles ensues for fw = 70-90%, as reflected by a gradual decrease in the emission intensity. It is shown that the suspension of ground In-MOF particles in water permits sensing of metal ions, in particular Al3+ ions, by fluorescence quenching with detection at a sub-ppb level. The observed results comprise first demonstration of both mechanoluminescence and AEE of MOF particles.

Comparative evaluation of Air-Q blocker and Proseal laryngeal mask airway in patients undergoing elective surgery under general anaesthesia: A randomised controlled trial.

BACKGROUND AND AIMS: The Air-Q blocker (Cook gas LLC, Mercury Medical, Clearwater, FL, USA) is a relatively new supraglottic airway device (SAD) with capability to serve as a conduit for intubation. As there is limited data on Air-Q blocker, the present study was performed to compare the efficacy of Air-Q blocker and Proseal laryngeal mask airway (PLMA) in patients undergoing elective surgery. METHODS: A total of 90 American Society of Anesthesiologists (ASA) physical status I and II patients were randomly allocated to Air-Q blocker or PLMA group. Oropharyngeal leak pressure (OLP), insertion success, insertion time, ease of orogastric tube (OGT) insertion, fibreoptic visualisation of the glottis, haemodynamic and ventilation parameters, and complications at emergence and postoperatively were investigated. RESULTS: OLPs were higher in PLMA group as compared to Air-Q blocker group (P = 0.002). Still, the OLP (27.5 ± 5.8 cm H2O) was clinically effective in Air-Q blocker group. The mean time for successful insertion was significantly shorter for Air-Q blocker than PLMA (P = 0.019). The number of attempts to insert both the devices was comparable (P ≥ 0.05). Air-Q blocker provided a significantly better fibreoptic score than PLMA (P = 0.038). The two groups were comparable in terms of ease of OGT insertion, haemodynamics and ventilation parameters, and complications at emergence and postoperatively. CONCLUSIONS: Air-Q blocker provides a clinically effective OLP though PLMA provides a slightly better sealing function in patients undergoing laparoscopic and non-laparoscopic surgeries under general anaesthesia requiring neuromuscular blockade. Air-Q blocker has shorter insertion time and a better fibreoptic view of glottis as compared to PLMA.

Comparison of different types of stylets with no-stylet technique for intubation with C-MAC D-Blade® videolaryngoscope in simulated difficult airway: A prospective randomized study.

BACKGROUND: The angulated C-MAC D-Blade videolaryngoscope (VL) is designed for difficult intubation and may not be compatible with standard PVC endotracheal tubes. OBJECTIVE: Present study was planned to compare efficacy of C-MAC, D-blade VL using endotracheal tube with three different stylets versus No stylet in patients undergoing tracheal intubation with simulated difficult airway. METHODS: After obtaining written consent and IEC approval, total 144 adult patients were allocated to four groups of 36 each using no stylet or different types of stylets. The four groups were Group NS: No stylet; Group CS: C-MAC stylet; Group DS: D-blade type stylet; Group HS: hockey-stick shaped stylet. A rigid appropriate sized Philadelphia cervical collar was placed around the neck to simulate difficult airway and C-MAC D-Blade VL was used for intubation. The duration of each intubation stage and attempts were evaluated. Statistical analysis was performed using SPSS 22.0 for Windows and appropriate tests for different variables were applied. Appropriately, Student's t test, Chi-square test, Mann-Whitney U test and one-way ANOVA test were applied. RESULTS: Similar Cormack Lehane grade glottic view was observed in all groups. The number of attempts and duration of intubation was significantly greater using NS than for other groups. Additional laryngeal manipulation, was required in all cases in Group NS, compared to one, zero and two cases in group CS, DS and HS respectively (p<0.001). CONCLUSION: Use of Hockey stick shaped, D blade shaped stylet and C Mac stylet decreased the total intubation duration in patients with simulated difficult airway.

Does an acute pain service improve the perception of postoperative pain management in patients undergoing lower limb surgery? A prospective controlled non-randomized study.

BACKGROUND AND AIM: An acute pain service (APS) has been running in our institute since April 2013 and is managed by the Department of Anesthesia and Intensive Care. However, it is not clear to what extent the patients feel benefited from the APS. The aim of the study was to compare the perception of postoperative pain management in patients receiving care under APS with those receiving routine postoperative pain relief following lower limb surgery. MATERIAL AND METHODS: This was a prospective, hospital-based, controlled non-randomized study. American Society of Anesthesiologists (ASA) grades I-III patients with age 18-75 years undergoing lower limb orthopedic surgery were prospectively recruited into APS (index group) or routine postoperative care (control group) (n = 55 each). Postoperatively, American Pain Society Patient Outcome Questionnaire-Revised (APS-POQ-R) and Short Form (SF-12) were used to evaluate the outcome of postoperative pain management at 24 h and health-related quality of life after 4 weeks respectively. RESULTS: Both groups were comparable in terms of demographic data. Patients in the index group had statistically significant better perception of care than the control group. Index group scored significantly higher than control group on median patient satisfaction score (9; interquartile range [IQR] [7-10] vs. 5 [3-6]; P < 0.001). In index group, there was significant reduction of worst pain in first 24 h along with decreased frequency of severe pain. CONCLUSION: Implementation of acute pain service plays an important role in improving the quality of postoperative pain relief, perception of care, and patient satisfaction.

Temperature-Dependent Emission and Turn-Off Fluorescence Sensing of Hazardous "Quat" Herbicides in Water by a Zn-MOF Based on a Semi-Rigid Dibenzochrysene Tetraacetic Acid Linker.

A zinc metal-organic framework, i.e., Zn-MOF (Zn-DBC), with ca. 27% solvent-accessible void volume was synthesized from a rationally designed tetraacid based on sterically insulated dibenzo[g,p]chrysene core; the latter inherently features concave shapes. Due to rigidification of the fluorophore in the MOF, Zn-DBC exhibits a respectable fluorescence quantum yield of ca. 30% in the solid state. The fluorescent and water-stable Zn-DBC MOF was found to display intriguing temperature-dependent emission behavior with an activation barrier of 1.06 kcal/mol for radiationless deactivation from the singlet-excited state. It is shown that the Zn-MOF can be employed as an efficient sensory material for detection of hazardous "quat" dicationic herbicides in water by diffusion-limited "turn-off" fluorescence. Due to confinement of the cationic guest analytes within the pores of the MOF, the fluorescence quenching via excited-state charge transfer mechanism is shown to depend on the molecular size of the analyte in addition to the redox potentials. Remarkably, Zn-DBC permits sensing of DQ, a well-known toxic "quat" herbicide, with a detection limit as low as 2.8 ppm in water. The unique structural attributes of the Zn-MOF for highly efficient fluorescence sensing of toxic herbicides in water are thus exemplified for the first time.

Serotonin Syndrome in ICU-A Road Less Traveled.

A potentially life-threatening adverse drug reaction, serotonin syndrome (SS) may occur in patients on serotonin agonist medications. Medications responsible for SS include commonly prescribed antidepressants, anxiolytics, analgesics and antiemetics. This syndrome has been mentioned in various scenarios in perioperative setting but rarely acknowledged in intensive care unit (ICU) setting. Multiple comorbities leading to polypharmacy and serotoninergic medications place elderly patients, particularly at higher risk of SS. We wish to report a case of SS in an elderly male with depression who developed SS and required ICU admission. Most crucial point is to be able to recognize this entity whenever a patient on multiple drugs with altered sensorium is admitted to ICU. HOW TO CITE THIS ARTICLE: Jindal S, Gombar S, Jain K. Serotonin Syndrome in ICU-A Road Less Traveled. Indian J Crit Care Med 2019;23(8):376-377.