Distribution of Bacterial Contamination in Partial Penetration Surrogate Ballistic Wounds

2020 ◽  
Author(s):  
Michelle R. Frybarger ◽  
Karim H. Muci-Küchler
Keyword(s):  
High Speed ◽  
Bacterial Contamination ◽  
Soft Tissues ◽  
Test Tube ◽  
Armed Conflicts ◽  
Front Face ◽  
Buffer Solution ◽  
Treatment Protocols ◽  
Partial Penetration ◽  
Permanent Cavity

Abstract With the rise in use of IEDs during armed conflicts, there has been an increase in the number of injuries to the extremities. Shrapnel and debris ejected during the explosion become high-speed projectiles capable of penetrating soft tissues, bringing bacterial contamination into the wound. If not properly treated, that contamination could lead to infection. Studies aimed at understanding the distribution of bacterial contamination along the permanent cavity could provide useful information to improve treatment protocols for these types of injuries. In this paper, a lower extremity surrogate model was used to investigate bacterial distribution in partial penetration ballistic wounds. The targets used were ballistic gelatin blocks that had an Escherichia coli-laden filter paper placed on their front face. Spherical projectiles were fired into the targets adjusting their speed to obtain three different partial penetration depths. After each shot, a gelatin strip containing the permanent cavity was extracted and segmented. The permanent cavity was removed from each segment, placed in a test tube with buffer solution, and heated in a water bath to melt the gelatin. Standard microbiology protocols were followed to determine the number of colony forming units (CFUs) in each segment. The bacteria distribution was represented by percent of total CFU in the permanent cavity versus segment number. In addition, bacterial contamination as a function of projectile penetration depth was explored. For the cases considered, most of the bacterial contamination occurred in the segments closer to the projectile entry point.

scholarly journals ANALYSIS OF EXPERIENCE IN THE APPLICATION OF MISSILE LAUNCH DETECTION SYSTEMS

2021 ◽  
pp. 118-129
Author(s):  
A. Pinchuk ◽  
M. Garbuz ◽  
P. Zeleny ◽  
D. Harnets ◽  
D. Ivanov
Keyword(s):  
High Speed ◽  
Armed Forces ◽  
The United States ◽  
Armed Conflicts ◽  
Desert Storm ◽  
Detection Systems ◽  
The Face ◽  
Protected Object ◽  
Conducting Research ◽  
The Impact

Analysis of combat losses of aircraft in local armed conflicts in recent decades shows that most cases of aircraft hits are related to the impact of guided surface-to-air and air-to-air missiles equipped with homing warheads. The use of modern guided missiles equipped with homing warheads is one of the main threats to aircraft of various types. This is due to the fact that modern guided missiles are characterized by high speed, maneuverability, accuracy of aiming and difficulty of detection. Solving the problem of protecting aircraft from guided missiles consists of several stages: detection of missile launch; confirmation that the detected missile is heading directly toward the protected object; missile identification and decision-making on the most effective countermeasure system employment. At present, there are no missile launch detection systems that guarantee a 100% probability of threat detection, but an analysis of aviation combat losses in local armed conflicts in recent decades convincingly shows that the number of combat losses of aircraft equipped with such systems is much lower than those in which missile launch detection is carried out visually. For example, most of the Soviet Union's losses during the war in Afghanistan and the United States‟ losses during Operation “Desert Storm” in Iraq were related to the use of portable anti-aircraft missile systems, which missiles were equipped with infrared homing warheads. Realizing the scale of the threat posed by such missiles, most of the world's leading countries have significantly increased the expenses on development new or improvement existing countermeasures. As a result, the aggregate losses of coalition forces in Iraq, Afghanistan and Syria since 2001 clearly suggest that these costs have paid off, with losses from the use of portable anti-aircraft missile systems significantly reduced, while the total number of combat sorties increased. Therefore, in the face of all the challenges and threats posed to Ukraine due to the aggressive actions of the Russian Federation, conducting research in the interests of aviation of the Armed Forces of Ukraine to improve the effectiveness of missile detection systems for ensuring timely detection of threats, warning of aircraft crew and activation in the automatic mode the means of countermeasures is as relevant as ever.

An experimental investigation of incipient spilling breakers

2009 ◽  
Vol 633 ◽  
pp. 271-283 ◽  
Author(s):  
J. D. DIORIO ◽  
X. LIU ◽  
J. H. DUNCAN
Keyword(s):  
Wave Breaking ◽  
High Speed ◽  
Phase Speed ◽  
Breaking Waves ◽  
Front Face ◽  
Geometrical Parameters ◽  
Instability Mechanism ◽  
Scaling Relationships ◽  
Self Similar ◽  
Spilling Breakers

In the present paper, the profiles of incipient spilling breaking waves with wavelengths ranging from 10 to 120cm were studied experimentally in clean water. Short-wavelength breakers were generated by wind, while longer-wavelength breakers were generated by a mechanical wavemaker, using either a dispersive focusing or a sideband instability mechanism. The crest profiles of these waves were measured with a high-speed cinematic laser-induced fluorescence technique. For all the wave conditions reported herein, wave breaking was initiated with a capillary-ripple pattern as described in Duncan et al. (J. Fluid Mech., vol. 379, 1999, pp. 191–222). In the present paper, it is shown that at incipient breaking the crest shape is self-similar with two geometrical parameters that depend only on the slope of a particular point on the front face of the gravity wave. The scaling relationships appear to be universal for the range of wavelengths studied herein and hold for waves generated by mechanical wavemakers and by wind. The slope measure is found to be dependent on the wave phase speed and the rate of growth of the crest height prior to incipient breaking.

Management of recurrent post-traumatic seroma of thigh (Morel-Lavallée lesion) by percutaneous aspiration and sclerotherapy using tetracyclines (PAST)

2021 ◽  
Vol 14 (1) ◽  
pp. e238804
Author(s):  
Arunesh Gupta ◽  
Vineet Kumar ◽  
Apurva Agarwal ◽  
Aneesh Suresh
Keyword(s):  
Early Diagnosis ◽  
Conservative Management ◽  
Bacterial Contamination ◽  
Soft Tissues ◽  
Successful Outcome ◽  
Serous Fluid ◽  
Percutaneous Aspiration ◽  
Post Traumatic ◽  
Open Debridement ◽  
Definitive Management

Morel-Lavallée lesion is a chronic, recurrent collection of serous fluid in the soft tissues and usually occurs following injury. The most common sites are thigh, hip and pelvic region. This presents as a local or diffuse swelling and may cause discomfort to the patient besides being a potential site for bacterial contamination. So, early diagnosis and timely management is crucial for an early and successful outcome. The investigation modality of choice for diagnosis of these lesions is MRI. Definitive management ranges from percutaneous aspiration with or without sclerotherapy to open debridement and irrigation. Although recurrences are common with conservative management, it can be minimised with judicious use of sclerotherapy.

scholarly journals Assisted Reproductive Technology as a Transcutaneous Route for Bacterial Contamination of Ovarian Endometrioma with Coagulase-Negative Staphylococcus: Case Report and Review of the Literature

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Shimon Edelstein ◽  
Inbar Ben Shachar ◽  
Hila Ben-Amram ◽  
Seema Biswas ◽  
Naama Marcus
Keyword(s):  
Assisted Reproductive Technology ◽  
Bacterial Contamination ◽  
Soft Tissues ◽  
Group B Streptococcus ◽  
Rare Condition ◽  
Oocyte Retrieval ◽  
Reproductive Technology ◽  
Causative Organism ◽  
Coagulase Negative Staphylococcus ◽  
Group B

Tubo-ovarian abscess may develop in women with endometrioma following assisted reproductive technology (ART). The infection, though rare, is typically late in onset and may present several months after the procedure, and in pregnancy—with the risks of abortion and premature labor. It is thought that transcutaneous oocyte retrieval during ART is the route for bacterial contamination resulting in infection of the endometrioma. Pathogens reported in the literature include Escherichia coli (E. coli) and Group B streptococcus (GBS) but Staphylococcus lugdunensis (S. lugdunensis), a coagulase-negative staphylococcus (CoNS), and groin and perineal skin commensal was isolated from the endometrioma in this case. We discuss the challenges in diagnosis and treatment of this rare condition and the implications of the discovery that an organism previously dismissed as a contaminant has emerged as a causative organism in severe, deep-seated infections of soft tissues in recent literature.

scholarly journals Preparation, Characterization, and In Vitro Evaluation of Resveratrol-Loaded Cellulose Aerogel

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1624
Author(s):  
Lili Qin ◽  
Xinyu Zhao ◽  
Yiwei He ◽  
Hongqiang Wang ◽  
Hanjing Wei ◽  
...  
Keyword(s):  
High Speed ◽  
Drug Carrier ◽  
Phosphate Buffer Solution ◽  
Gastric Fluid ◽  
Simulated Gastric Fluid ◽  
Oxidized Cellulose ◽  
Buffer Solution ◽  
Aggregation State ◽  
Cellulose Aerogel

Resveratrol is a natural active ingredient found in plants, which is a polyphenolic compound and has a variety of pharmaceutical uses. Resveratrol-loaded TEMPO-oxidized cellulose aerogel (RLTA) was prepared using a freeze-drying method, employing high speed homogenization followed by rapid freezing with liquid nitrogen. RLTAs were designed at varying drug–cellulose aerogel ratios (1:2, 2:3, 3:2, and 2:1). It could be seen via scanning electron microscopy (SEM) that Res integrated into TEMPO-oxidized cellulose (TC) at different ratios, which changed its aggregation state and turned it into a short rod-like structure. Fourier transform infrared (FTIR) spectra confirmed that the RLTAs had the characteristic peaks of TC and Res. In addition, X-ray diffraction (XRD) demonstrated that the grain size of RLTA was obviously smaller than that of pure Res. RLTAs also had excellent stability in both simulated gastric fluid and phosphate buffer solution. The drug release rate was initially completed within 5 h under a loading rate of 30.7 wt%. The results of an MTT assay showed the low toxicity and good biocompatibility of the RLTAs. TC aerogel could be a promising drug carrier that may be widely used in designing and preparing novel biomedicine.

Rapid Electroanalytical Method for Determination of Nebivolol at a Boron-Doped Diamond Electrode

2015 ◽  
Vol 98 (6) ◽  
pp. 1535-1541 ◽  
Author(s):  
Biljana Nigović ◽  
Ana Mornar ◽  
Mario Završki
Keyword(s):  
High Speed ◽  
Comparative Method ◽  
Potential Range ◽  
Boron Doped Diamond ◽  
Buffer Solution ◽  
Diamond Electrode ◽  
Boron Doped ◽  
Boron Doped Diamond Electrode ◽  
Electroanalytical Method

Abstract A boron-doped diamond electrode provided a sensitive and cost-effective sensing platform for detection and quantitative determination of novel beta(1)-adrenergic receptor antagonist nebivolol. The net square-wave voltammetric response at 1.31 V related to the oxidation of nebivolol was obtained in Britton-Robinson buffer solution at pH 8. It increased linearly with the drug concentration in the range of 2.5 × 10–7 to 1.5 × 10–5 M. The LOD attained was 3.2 × 10–8 M. The practical analytical approach was illustrated by high speed quantification of nebivolol in a commercial pharmaceutical formulation. The RP-HPLC was selected as a comparative method for evaluating the proposed electroanalytical method. The newly developed method at the unmodified electrode surface was faster and simpler in comparison with HPLC (the retention time was 17.6 min), and only 6 s was necessary for direct voltammetric measurement in the potential range from 0.5 to 1.7 V with a 2 mV potential step and pulse frequency of 100 Hz.

Protein crystals IR laser ablated from aqueous solution at high speed retain their diffractive properties: applications in high-speed serial crystallography

2017 ◽  
Vol 50 (6) ◽  
pp. 1773-1781 ◽  
Author(s):  
Eike C. Schulz ◽  
Johannes Kaub ◽  
Frederik Busse ◽  
Pedram Mehrabi ◽  
Henrike M. Müller-Werkmeister ◽  
...  
Keyword(s):  
High Speed ◽  
Vibrational Excitation ◽  
Protein Crystals ◽  
Buffer Solution ◽  
High Repetition ◽  
High Speeds ◽  
Large Numbers ◽  
Heating Effects ◽  
Serial Crystallography ◽  
Jet Injectors

In order to utilize the high repetition rates now available at X-ray free-electron laser sources for serial crystallography, methods must be developed to softly deliver large numbers of individual microcrystals at high repetition rates and high speeds. Picosecond infrared laser (PIRL) pulses, operating under desorption by impulsive vibrational excitation (DIVE) conditions, selectively excite the OH vibrational stretch of water to directly propel the excited volume at high speed with minimized heating effects, nucleation formation or cavitation-induced shock waves, leaving the analytes intact and undamaged. The soft nature and laser-based sampling flexibility provided by the technique make the PIRL system an interesting crystal delivery approach for serial crystallography. This paper demonstrates that protein crystals extracted directly from aqueous buffer solutionviaPIRL-DIVE ablation retain their diffractive properties and can be usefully exploited for structure determination at synchrotron sources. The remaining steps to implement the technology for high-speed serial femtosecond crystallography, such as single-crystal localization, high-speed sampling and synchronization, are described. This proof-of-principle experiment demonstrates the viability of a new laser-based high-speed crystal delivery system without the need for liquid-jet injectors or fixed-target mounting solutions.

Axial Strain Measurements in Skeletal Muscle at Various Strain Rates

1995 ◽  
Vol 117 (3) ◽  
pp. 262-265 ◽  
Author(s):  
T. M. Best ◽  
J. H. McElhaney ◽  
W. E. Garrett ◽  
B. S. Myers
Keyword(s):  
Skeletal Muscle ◽  
Strain Field ◽  
High Speed ◽  
Soft Tissues ◽  
Axial Strain ◽  
Local Strain ◽  
Optical Systems ◽  
Rate Dependent ◽  
Strain Formulation ◽  
Tissue Deformations

A noncontact optical system using high speed image analysis to measure local tissue deformations and axial strains along skeletal muscle is described. The spatial resolution of the system was 20 pixels/cm and the accuracy was ±0.125mm. In order to minimize the error associated with discrete data used to characterize a continuous strain field, the displacement data were fitted with a third order polynomial and the fitted data differentiated to measure surface strains using a Lagrangian finite strain formulation. The distribution of axial strain along the muscle-tendon unit was nonuniform and rate dependent. Despite a variation in local strain distribution with strain rate, the maximum axial strain, Exx = 0.614 ± 0.045 mm/mm, was rate insensitive and occurred at the failure site for all tests. The frequency response of the video system (1000 Hz) and the measurement of a continuous strain field along the entire length of the structure improve upon previous noncontact optical systems for measurement of surface strains in soft tissues.

Stall Precursor Identification in High Speed Compressor Stages Using Chaotic Time Series Analysis Methods

1996 ◽  
Author(s):  
Michelle M. Bright ◽  
Helen K. Qammar ◽  
Harald J. Weigl ◽  
James D. Paduano
Keyword(s):  
Wave Energy ◽  
Energy Method ◽  
Traveling Wave ◽  
High Speed ◽  
Pressure Fluctuations ◽  
Correlation Method ◽  
Rotating Stall ◽  
Front Face ◽  
Stable Operation ◽  
Correlation Integral

This paper presents a new technique for precursor identification in high speed compressors. The technique is a pseudo-correlation integral method referred to as the correlation method. To provide a basis for comparison, the traveling wave energy technique, which has been used extensively to study pre-stall data, is also briefly presented and applied. The correlation method has a potential advantage over the traveling wave energy method because it uses a single sensor for detection. It also requires no predisposition about the expected behavior of the data to detect “changes” in the behavior of the compressor. Both methods are used in this study to identify stall procursive events in the pressure fluctuations measured from circumferential pressure transducers located at the front face of the compressor rig. The correlation method successfully identified stall formation or changes in the compressor dynamics from data captured from four different configurations of a NASA Lewis single stage high speed compressor while it was transitioned from stable operation into stall. This paper includes an exposition on the use of nonlinear methods to identify stall precursors, a description of the methodologies used for the study, information on the NASA high speed compressor rig and experimental data acquisition, and results from the four compressor configurations. The experimental results indicate that the correlation method provides ample warning of the onset of rotating stall at high speed, in some tests on the order of 2000 rotor revolutions. Complementary features of the correlation method and the traveling wave energy method are discussed, and suggestions for future developments are made.

Characterization of Switching Time and Cell Stress in a Gravity-Driven Microfluidic Cell Sorter Based on Hydrodynamic Switching

2010 ◽  
Author(s):  
Michael Grad ◽  
Lubomir Smilenov ◽  
David Brenner ◽  
Daniel Attinger
Keyword(s):  
High Speed ◽  
Bystander Effect ◽  
Fluorescent Protein ◽  
Switching Time ◽  
Blue Dye ◽  
Adhesive Tape ◽  
Buffer Solution ◽  
Cell Sorter ◽  
Microfluidic Cell Sorter

In this work we describe the control and characterization of the switching time and hydrodynamic stress in a microfluidic cell sorter. The device was designed to sort small (<1000) populations of live cells in buffer solution labeled with standard bio-markers such as live dyes or green fluorescent protein (GFP). Sorting occurs through a hydrodynamic switching technique where high-speed solenoid valves control a sheath flow used to steer sorted cells away from the unsorted bulk population. The device is constructed from a reusable hard plastic polymethylmethacrylate (PMMA) chip machined with 127μm × 50μm microchannels and sealed with adhesive tape. Open reservoirs in the chip facilitate pipette access, standard microscope visualization, and a simple disassembly and cleaning procedure. The sorting frequency of this type of device is typically limited by the hydrodynamic switching time. Here, we present a theoretical and numerical analysis of the device switching time. These results show that the sorter switching time t is practically limited by the velocity of the flow and the characteristic length between inlet and outlet channels. We validate this theoretical result with experimental data obtained from flow visualizations, along with experiments conducted to evaluate the repeatability of the hydrodynamic switching scheme and the survival rate of sorted fibroblast cells Manually operated, the sorting frequencies were approximately 10 cells per minute, with switching time constants of approximately 130ms. Current throughput is limited by this switching time to approximately 450 cells per minute. Automation can increase the velocity and reduce the spacing between cells, thereby increasing throughput by at least an order of magnitude. The cell sorter was then tested by manually sorting 100 beads in 7 minutes, and 30 cells in less than 3 minutes, and was successfully used in the framework of a study on the bystander effect occurring during cell irradiation. Experiments with Trypan Blue dye verified that cell viability was maintained during the sorting process.

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