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Blast and fragmentation of a scaled down model of standard artillery shell is investigated experimentally and numerically. Simple experimental techniques are employed in this study to measure the fragments’ velocity, mass and spatial distribution. Fragments of mass ranging from tens of milligram(s) to 6.4 grams are produced with velocities ranging from 960 to 1555 m/s. The cylindrical part of the shell has larger contribution among high velocity fragments ~1369-1555m/s than the conical and rear parts due to higher charge to mass (C/M) ratio. Overpressure of 44.2psi (304.7kPa) is measured at stand-off distance of 0.550m. The numerical simulation of fragmentation is carried out using Smoothed Particle Hydrodynamics (SPH) solver available in ANSYS AUTODYN. A coupled Euler-ALE (Arbitrary Lagrangian-Eulerian) approach is used to simulate the shell blast propagation in the surrounding air. A good agreement is achieved between the simulation and experimental results. The investigation can help in the development of protective configurations against the damaging effects of blast and fragmentation.

Objectives COVIDTrach is a UK multicentre prospective cohort study project that aims to evaluate the outcomes of tracheostomy in patients with COVID-19 receiving mechanical ventilation and record the incidence of SARS-CoV-2 infection among healthcare workers involved in the procedure.Design Data on patient demographic, clinical history and outcomes were entered prospectively and updated over time via an online database (REDCap). Clinical variables were compared with outcomes, with logistic regression used to develop a model for mortality. Participants recorded whether any operators tested positive for SARS-CoV-2 within 2 weeks of the procedure.Setting UK National Health Service departments involved in treating patients with COVID-19 receiving mechanical ventilation.Participants The cohort comprised 1605 tracheostomy cases from 126 UK hospitals collected between 6 April and 26 August 2020.Main outcome measures Mortality following tracheostomy, successful wean from mechanical ventilation and length of time from tracheostomy to wean, discharge from hospital, complications from tracheostomy, reported SARS-CoV-2 infection among operators.Results The median time from intubation to tracheostomy was 15 days (IQR 11, 21). 285 (18%) patients died following the procedure. 1229 (93%) of the survivors had been successfully weaned from mechanical ventilation at censoring and 1049 (81%) had been discharged from hospital. Age, inspired oxygen concentration, positive end-expiratory pressure setting, fever, number of days of ventilation before tracheostomy, C reactive protein and the use of anticoagulation and inotropic support independently predicted mortality. Six reports were received of operators testing positive for SARS-CoV-2 within 2 weeks of the procedure.Conclusions Tracheostomy appears to be safe in mechanically ventilated patients with COVID-19 and to operators performing the procedure and we identified clinical parameters that are predictive of mortality.Trial registration number The study is registered with ClinicalTrials.Gov (NCT04572438).

The aim of the present study was to investigate Echinococcus granulosus genotypes in the Kashmir valley. A total of 2,100 sheep and human patients were screened for the presence of hydatidosis. Total 87 isolates were collected, 85 from sheep and 2 isolates from human beings. The rDNA-ITS1 fragment were amplified with BD1 / 4S primers. In addition, fragments of genes coding for ITS1 were sequenced. The length of amplified fragment for all isolated samples with sheep origin was 1,000 bp and with human origin was between 1,000 bp and 1,100 bp. The products on digestion with restriction enzymes Rsa 1, Alu 1, Msp 1 yielded identical fragments, 300 and 700 bp in sheep and 325 and 700 bp in humans. Intact 1000 bp fragment was observed with Taq 1. The molecular findings reveal that sheep strain (G1) is the predominant genotype in sheep and humans in Kashmir valley.

In this study, the synthesis-structure-property relationship of graphene-reinforced Al matrix nanocomposites was investigated. The Al-Li-GNPs nanocomposite was synthesized to attain both high strength and good ductility. The incorporation of GNPs as a reinforcement in the Al-based matrix provided a nanocomposite structure for an integrated strengthening effect. To promote plasticity and maintain good ductility, the nanocrystalline Al matrix was alloyed with Li to reduce its stacking fault energy and promote additional deformation mechanisms. The compressive yield strength (CYS) increased from 88 MPa for the starting Al to 403 MPa for the Al-Li-GNPs nanocomposites with 1.0 wt% GNPs. Fracture analysis indicated that the synthesized nanocomposite exhibited a ductile nature and significant plastic deformation. Based on microscopic analysis, the enhanced strength of the Al-Li-GNPs nanocomposite was attributed to grain refinement, load transfer, and strain hardening. The good ductility, on the other hand, was attributed to dislocation slipping, the formation of stacking faults, and twinning.

Influence of 30 kilo-electron-volt (keV) Argon (Ar ^+ ) ions on optical and electrical properties of nickel nanowires (Ni-NWs) meshes is being reported. Ni-NWs are being exposed to 30 keV Argon (Ar ^+ ) ions at various beam fluencies. These fluencies of Ar ^+ ions are 7 × 10 ^14 ions cm ^−2 , 3 × 10 ^15 ions cm ^−2 and 3 × 10 ^16 ions cm ^−2 . After irradiation, Ni-NWs meshes were analyzed through transmission electron microscopy technique (TEM). The structural analysis has been done through X-ray diffraction technique. It is found from TEM results that atoms are sputtered out from surfaces of Ni-NWs due to collision cascade effect persistently and lead to reduce the diameters or thicknesses of Ni-NWs. X-ray diffraction results reveal that crystalline quality is reduced under Ar ^+ ions irradiation which may be due to defects induced in Ni-NWs as a result of collision cascade effect. The Ni-NWs meshes are characterized optically and electrically through UV–VIS spectroscopy and four probe techniques. The optical transparencies of Ni-NWs meshes are increasing with increase in beam fluence of Ar ^+ ions. The electrical conductivity of the mesh is decreased continuously with increment in beam fluence of Ar ^+ ions which might be due to production of defects in Ni-NWs. The tuning of optical transparency and electrical conductivity of Ni-NWs meshes is required for their application as successful transparent electrodes in optoelectronic nanodevices.

In this article, axisymmetric stagnation-point flow of a third-grade fluid over a disk lubricated with a power law fluid is considered. Due to thin lubrication layer of variable thickness, third-grade fluid experiences a partial slip on the surface. The flow problem is governed through a system of nonlinear partial differential equations with nonlinear boundary conditions. A nonsimilar solution is presented in this article by implementing hybrid homotopy analysis method. This method combines the features of homotopy analysis and shooting methods. The results varying from no-slip to full-slip case are discussed under the influence of pertinent parameters.

Osteopetrosis is a rare metabolic disease. Dental abnormalities may be attributed to the pathological changes in osteopetrosis. Patients with disease seem to be especially susceptible to osteomyelitis of mandible. A 9 yrs old girl presented with complaints of jaw swelling on left side with multiple discharging sinuses since last seven months. The radiograph of left mandible (oblique lateral view) showed periodontal involvement of associated molars with loss of lamina dura with small sequestrum with irregularity and erosions of the mandibular cortical margins. The patient was diagnosed as a case of osteopetrosis with superadded mandibular osteomyelitis.

Acute pancreatitis is a common cause of acute abdominal pain and is associated with a wide variety of complications. Pancreatic necrosis is one of the most important complications and is considered to be the most important indicator of disease severity as the increased frequency of death in acute pancreatitis is directly correlated with the development and extent of pancreatic necrosis. In addition to pancreatic necrosis, wide spectrums of colonic complications have been described, including functional and mechanical ileus, ischemic necrosis and fistula formation. In acute pancreatitis bowel ischemia usually involves the transverse colon or the hepatic and splenic flexures and may range in severity from mild superficial mural involvement totransmural colonic necrosis. This article reports a case of large bowel infarction as a complication of severe necrotizing pancreatitis in a 35-year-old male patient.

Cyclohexylamine oxidase (CHAO) is a flavoprotein first described in Brevibacterium oxydans strain IH-35A that carries out the initial step of the degradation of the industrial chemical cyclohexylamine to cyclohexanone. We have cloned and expressed in Escherichia coli the CHAO-encoding gene (chaA) from B. oxydans, purified CHAO and determined the structures of both the holoenzyme form of the enzyme and a product complex with cyclohexanone. CHAO is a 50 kDa monomer with a PHBH fold topology. It belongs to the flavin monooxygenase family of enzymes and exhibits high substrate specificity for alicyclic amines and sec-alkylamines. The overall structure is similar to that of other members of the flavin monooxygenase family, but lacks either of the C- or N-terminal extensions observed in these enzymes. Active site features of the flavin monooxygenase family are conserved in CHAO, including the characteristic aromatic cage. Differences in the orientations of residues of the CHAO aromatic cage result in a substrate-binding site that is more open than those of its structural relatives. Since CHAO has a buried hydrophobic active site with no obvious route for substrates and products, a random acceleration molecular dynamics simulation has been used to identify a potential egress route. The path identified includes an intermediate cavity and requires transient conformation changes in a shielding loop and a residue at the border of the substrate-binding cavity. These results provide a foundation for further studies with CHAO aimed at identifying features determining substrate specificity and for developing the biocatalytic potential of this enzyme.

Perivascular or Virchow-Robin spaces (VR) of the brain are fluid-filled, pial-lined spaces that accompany the cerebral vessels as they pass from subarachnoid space into the brain parenchyma. They are visualized on routine MR examinations as CSF intensity spaces and are normally < 2 mm in size. These spaces may rarely enlarge massively and can be mistaken for more ominous pathologic processes on CT scan and even on MRI, but careful examination on special sequences and follow-up examination can clear the uncertainty. We describe a case of a young male who presented with mildly progressive neurological symptoms and the imaging findings were typical of enlarged VR spaces. Patient was advised follow up and is doing well.

Intradural extramedullary type of spinal hydatid disease is a rare variety of hydatid disease, and is even rarer in paediatric age group. Spinal hydatid disease should be considered in the differential diagnosis of spinal cord compression syndrome in endemic countries and should be evaluated with imaging and serological investigations. Our case was a 9- year-old boy who presented with lower back pain lasting for 8 months and progressive bilateral lower extremities weakness lasting for 2 month. Neurological examination was suggestive of lower motor neuron type of paraperesis. Magnetic resonance images of the lumbar spine showed an intradural cystic lesion displacing and compressing the lower cord and cauda equina. The cystic mass was explored with L1-L4 laminectomy and after durotomy; it was separated from cord and dura mater by hydrodissection. It contained a clear fluid. The pathological diagnosis was hydatid disease.