Haemorrhage control beyond Advanced Trauma Life Support (ATLS) protocol in life threatening maxillofacial trauma – experience from a level Ⅰ trauma centre

Maxillofacial injuries are usually not life-threatening and do not get priority over other associated injuries. However, some maxillofacial injuries with active oral or nasal bleeding need immediate management due to threatened airway and blood loss. In the case of major active vascular bleeding, measures such as local pressure, anterior nasal packing, posterior nasal packing, and balloon tamponade are ineffective. In these cases, angiography and transcatheter arterial embolisation (TAE) are used to treat life-threatening haemorrhage caused by maxillofacial trauma. We analysed the medical records of 39 patients with severe maxillofacial trauma and life-threatening haemorrhage that was a result of intractable oral or nasal bleeding. These patients were considered for TAE from January 2010 to December 2019. A total of 1668 patients was admitted, out of which 39 (2.3%) had severe maxillofacial injuries with life-threatening oral or nasal bleeding and underwent TAE. Out of a total of 39 patients, 38 were male and one female. Ages ranged from 16 to 65 years. Road traffic injury was the most common cause of injury (79.5%), Lefort I and II were the most common facial fractures, and traumatic brain injury was the most common associated injury. Embolisation and bleeding control were done successfully in all 39 patients with no procedure-related complications. A total of 17 deaths during the study period were due to severe traumatic brain injuries or haemorrhagic shock.     

Use of knotless barbed sutures for closure of intraoral incisions for maxillofacial trauma: a randomised controlled trial

The objective of this study was to assess the efficacy of knotless barbed sutures in intraoral wound closure for maxillofacial trauma in comparison with conventional (vicryl) sutures. This was a randomised controlled clinical trial involving 40 patients with isolated mandibular angle fractures who required intraoral incisions for open reduction and internal fixation (ORIF). The sample was randomised into the study group (20 patients) and control group (20 patients). Following fracture fixation by a standardised surgical protocol, the wound closure was done with bidirectional knotless barbed suture and vicryl for the study and control groups, respectively. The wounds were closed in layers (periosteum and mucosa). All operations were performed by a single surgeon. Outcome parameters measured were intraoperative wound closure time and wound healing using ‘Landry’s wound healing index’ on the first, third, and seventh postoperative days. Statistically significant difference in suturing time was noted between the study and control group (p value <0.001). The study group demonstrated a mean (SD) suturing time of 9.46 (2.01) minutes, compared with the 17.61 (2.57) minutes in the control group. Wound healing was found to be better and statistically significant in the study group than the control group (p value<0.001). Knotless barbed suture is a promising alternative to vicryl for intraoral wound closure.     

Anterior segmental osteotomies without orthodontics: practicability of the correction of dentoalveolar deformities

We designed this study to determine the efficiency and stability of anterior segmental osteotomies (ASO) without orthodontics for various dentofacial deformities. Records of patients treated with maxillary or mandibular ASO, or both, without orthodontics in the past 15 years were analysed. The assessment included postoperative analysis of patients’ aesthetics and functional satisfaction using a questionnaire and grading (score 0 - 4) system, and the amount of relapse calculated from 12-month postoperative cephalograms. A total of 26 ASO subjects (age range 13- 31 years) were studied (14 maxillary, two mandibular, and 10 bimaxillary). Long-term stability was acceptable in all cases with no significant relapse (p>0.05). No major complications were encountered. All patients reported good to excellent (score = 3 to 4) satisfaction following surgery. Using meticulous planning and a careful surgical technique, ASO without orthodontics is a simple, quick, safe, and stable option for the correction of dentofacial deformities.     

Impact of covid-19 pandemic on characteristics of dental emergencies and treatment services at tertiary care centre

PurposeTo categorize and compare the dental emergencies along with status of health services received in the tertiary dental health care centre during the pre covid- 19 periods and period of the complete lockdown in COVID 19 pandemic. Methods: A retrospective cross-sectional observational survey was conducted. Four different groups period were studied on patients who visited for dental emergencies at tertiary care centre. April 14 to 13 May 2020 assigned and analyzed as a test period group or group IV. The control period group i.e. group III was 14 February 2020 to 17 March, pre lockdown COVID 19 month when there was no consideration of epidemic in India. Same as periods of group II and IV, group I and II from last year 2019 were also assigned and analyzed. The tertiary care centre provision of health services during this pandemic was also inquired and evaluated. The information was recorded regarding availability of health services like non-emergency dental treatments, emergency dental services, and online professional consultation. To compare four different time period of obtained data, Analysis of variance (ANOVA) and Chi square test were used. Results: The overall proportion and percentage of dental emergencies were raised. The reason for emergency visits to dental clinic were the main problem related with pulpal (46.0%) followed by abscess (16.6%), periapical lesions (15.0%), cellulitis (4.1%) or trauma (0.3%). In lockdown most of the dental emergencies 228(2 6 5) were endodontic related (86.1%) which managed mostly through ‘3A” approach (advise, analgesics and antibiotics) (60.1%) and remaining (26.0%) through extraction.     

Blood plasma separation in elevated dimension T-shaped microchannel

In recent years, microfluidic chips have proven ideal tools for biochemical analysis, which, however, demands a unique and compatible plasma separation scheme. Various research groups have established continuous flow separation methods in microfluidic devices; however, they have worked with relatively small dimension microchannels (similar to the blood cell diameter). The present work demonstrates separation of plasma by utilizing the hydrodynamic separation techniques in microchannels with size of the order of mm. The separation process exploits the phenomenon, which is very similar to that of plasma skimming explained under Zweifach-Fung bifurcation law. The present experiments demonstrates for, the first time, that applicability of the Zweifach-Fung bifurcation law can be extended to dimensions much higher than the suspended particle size. The T-microchannel device (comprising perpendicularly connected blood and plasma channels) were micro-fabricated using conventional PDMS micro-molding techniques. Three variables (feed hematocrit, main channel width, and flow rate distributions) were identified as the important parameters which define the device’s efficiency for the blood plasma separation. A plasma separation efficiency of 99.7 % was achieved at a high flow ratio. Novel concepts of 2-stage or multiple plasma channel designs are also proposed to yield high separation efficiency with undiluted blood. The possible underlying principle causing plasma separation (viz. aggregation and shear thinning) are investigated in detail as part of this work. The results are significant because they show nearly 100 % separations in microchannels which are much easier to fabricate than previously designed devices.     

Novel huperzine A based NMDA antagonists: insights from molecular docking,ADME/T and molecular dynamics simulation studies

Huperzine A (HupA) is an alkaloidal natural product and drug isolated from Chinese herb Huperzia serrata, which is a potent selective anticholinesterase inhibitor. HupA has symptomatic, cognitive-enhancing and protective effect on neurons against amyloid beta-induced oxidative injury and antagonizing N-methyl-d-aspartate receptors by blocking the ion channels. The present study aimed to identify the docking, ADME/T and molecular dynamics simulation parameters of a library of 40 analogues which can correlate the binding affinity, conformational stability and selectivity of the ligands towards NMDA receptor through in silico approach. Glide molecular docking analysis was performed for the designed analogues to understand the binding mode and interactions. MD simulations were performed to explain the conformational stability and natural dynamics of the interaction in physiological environmental condition of protein–ligand complex affording a better understanding of chemical-scale interactions between HupA and its analogues with NMDA channel that could potentially benefit the development of new drugs for neurodegenerative diseases involving NMDA receptors.

The in silico study explores the structural behavior and binding affinities of 40 novel analogues of huperzine A. Novel NMDA receptor antagonists have been virtually identified by molecular docking, ADME/T and molecular dynamics simulation studies.     

Elastic distortion determining conduction in BiFeO3 phase boundaries

It is now well-established that boundaries separating tetragonal-like (T) and rhombohedral-like (R) phases in BiFeO₃ thin films can show enhanced electrical conductivity. However, the origin of this conductivity remains elusive. Here, we study mixed-phase BiFeO₃ thin films, where local populations of T and R can be readily altered using stress and electric fields. We observe that phase boundary electrical conductivity in regions which have undergone stress-writing is significantly greater than in the virgin microstructure. We use high-end electron microscopy techniques to identify key differences between the R–T boundaries present in stress-written and as-grown microstructures, to gain a better understanding of the mechanism responsible for electrical conduction. We find that point defects (and associated mixed valence states) are present in both electrically conducting and non-conducting regions; crucially, in both cases, the spatial distribution of defects is relatively homogeneous: there is no evidence of phase boundary defect aggregation. Atomic resolution imaging reveals that the only significant difference between non-conducting and conducting boundaries is the elastic distortion evident – detailed analysis of localised crystallography shows that the strain accommodation across the R–T boundaries is much more extensive in stress-written than in as-grown microstructures; this has a substantial effect on the straightening of local bonds within regions seen to electrically conduct. This work therefore offers distinct evidence that the elastic distortion is more important than point defect accumulation in determining the phase boundary conduction properties in mixed-phase BiFeO₃.

The localized crystallography of conducting and non-conducting phase boundaries in mixed-phase BiFeO₃ is directly compared using scanning transmission electron microscopy techniques.

The complexity of electrical conductivity in domain walls in BiFeO₃ (and in ferroics in general) is as multifaceted as ever. Various influences such as point defect accumulation, octahedral rotations, magnetic interactions and electrostatic discontinuities are thought to be possible mechanisms at play,^1–8 either alone or in combination. The research area of domain wall conductivity is currently flourishing and the view that domain walls offer exciting prospects in terms of engineering systems in which the domain walls act as distinct identities to the domains which they separate is now widely accepted. We believe that it is pertinent timing to address a lack of experimental investigations providing meaningful direct comparison of the localised crystallography and defect structure responsible for observed enhanced electrical conductivity. This study is stimulated by the interesting discoveries of conductive phase boundaries, specifically, in mixed-phase BiFeO₃.^9,10 By tuning the local populations of the tetragonal-like (T) and rhombohedral-like (R) phases in BiFeO₃ thin films via electric and stress fields, we demonstrate that electrical conductivity along phase boundaries is significantly greater after stress-writing. We probe the key crystallographic differences between the R–T boundaries created via stress, compared to those already present in the as-grown microstructures, to disentangle the mechanism determining electrical conduction in mixed-phase BiFeO₃.The growth of BiFeO₃ on substrates enforcing a large in-plane compressive strain drives the formation of monoclinic phases that are approximately rhombohedral (R) and tetragonal (T). Similar to materials such as PbZr_0.53Ti_0.47O₃ that straddle a morphotropic phase boundary, highly strained BiFeO₃ can readily undergo phase transitions between the R and T phases (and vice versa). The high-strain T phase exhibits a tetragonal-like symmetry (almost P4mm) with a c/a ratio of ∼1.2; the Fe displacement towards one of the apical oxygens along [001]_pc results in fivefold oxygen coordinated Fe, and an enhanced polarisation roughly 1.5 times that of the bulk single crystal.^7,11 The R phase, on the other hand, resembles the rhombohedral bulk phase (almost R3c), where the Fe is octahedrally coordinated, with a ferroelectric distortion along the pseudocubic [111]_pc axis, and antiferrodistortive rotations of the FeO₆ octahedra around [111]_pc occur. The crystal structure and misfit strain associated with the native (as-grown) R and T phases is reported elsewhere, both theoretically^12–15 and experimentally,^6,7,16–21 making it well-known that the ferroelectric and the antiferrodistortive degrees of freedom in mixed-phase BiFeO₃ set it apart from other typical perovskites. Notably, despite the ample evidence provided on phase reversal and characterisation of the as-grown phases, most of the literature (especially regarding electric field cycling of the mixed-phase state) has been primarily concerned with X-ray diffraction (XRD) i.e. global measurements that will not necessarily pick up on the more subtle, atomic-scale aspects of structure local to the phase boundaries. The importance of the study described herein resides in the uniqueness of creating microstructures such that both the as-grown and stress-induced R–T phase boundaries can be included within one single cross-sectional transmission electron microscopy (TEM) lamella; this gives the best possible scenario to allow meaningful direct comparison of the localised crystallography and defect structure responsible for the observed enhanced electrical conductivity found at stress-induced phase boundaries.