Publications by authors named "Joshua Cox"

21 Publications

  • Page 1 of 1

A 3D printed phantom to assess MRI geometric distortion.

Biomed Phys Eng Express 2021 Mar 3. Epub 2021 Mar 3.

Queensland University of Technology, 199 Ipswich Road, Brisbane, 4102, AUSTRALIA.

Magnetic Resonance has become a standard imaging modality for target volume delineation and treatment planning in radiation oncology. Geometric distortions, however, have the potential to detrimentally affect both tumour definition and the dose delivered to the target volume. We report the design, fabrication and imaging of a 3D printed unibody MR distortion phantom along with quantitative image analysis.

Methods: The internal cavity of the phantom is an orthogonal three-dimensional planar lattice, composed of 3mm diameter rods spaced equidistantly at a 20mm centre-centre offset repeating along the X, Y and Z axes. The phantom featured an overall length of 308.5 mm, a width of 246 mm and a height of 264 mm with lines on the external surface for phantom positioning matched to external lasers. The MR phantom was 3D printed in Nylon-12 using an advancement on traditional selective laser sintering (SLS) (HP Jet Fusion 3D - 4200 machine). The phantom was scanned on a Toshiba Aquilion CT scanner to check the integrity of the 3D print and to correct for any resultant issues. The phantom was then filled with NiSO4 solution and scanned on a 3T PET-MR Siemens scanner for selected T1 and T2 sequences, from which distortion vectors were generated and analysed using in-house software written in Python.

Results: All deviations were less than 1 mm, with an average displacement of 0.228 mm. The majority of the deviations are smaller than the 0.692 mm pixel size for this dataset.

Conclusion: A cost-effective, 3D printed MRI-phantom was successfully printed and tested for assessing geometric distortion on MRI scanners. The custom phantom with markings for phantom alignment may be considered for radiotherapy departments looking to add MR scanners for simulation and image guidance.
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http://dx.doi.org/10.1088/2057-1976/abeb7eDOI Listing
March 2021

Total Synthesis of (±)-Phyllantidine: Development and Mechanistic Evaluation of a Ring Expansion for Installation of Embedded Nitrogen-Oxygen Bonds.

Angew Chem Int Ed Engl 2020 06 8;59(24):9757-9766. Epub 2020 May 8.

Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, TX, 76798, USA.

The development of a concise total synthesis of (±)-phyllantidine (1), a member of the securinega family of alkaloids containing an unusual oxazabicyclo[3.3.1]nonane core, is described. The synthesis employs a unique synthetic strategy featuring the ring expansion of a substituted cyclopentanone to a cyclic hydroxamic acid as a key step that allows facile installation of the embedded nitrogen-oxygen (N-O) bond. The optimization of this sequence to effect the desired regiochemical outcome and its mechanistic underpinnings were assessed both computationally and experimentally. This synthetic approach also features an early-stage diastereoselective aldol reaction to assemble the substituted cyclopentanone, a mild reduction of an amide intermediate without N-O bond cleavage, and the rapid assembly of the butenolide found in (1) via use of the Bestmann ylide.
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http://dx.doi.org/10.1002/anie.202003829DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7448577PMC
June 2020

The Crisis of Clinical Education for Physicians in Training.

Mo Med 2019 Sep-Oct;116(5):389-391

W. Joshua Cox, DO, is Associate Dean, Clinical Education and Professor, and Gautam J. Desai, DO, is Professor. Both are in the Department of Primary Care, Kansas City University College of Osteopathic Medicine.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6797035PMC
April 2020

Mechanistic study of the formation of ring-retaining and ring-opening products from the oxidation of aromatic compounds under urban atmospheric conditions.

Atmos Chem Phys 2019 13;19(23):15117-15129. Epub 2019 Dec 13.

John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA02138, USA.

Aromatic hydrocarbons make up a large fraction of anthropogenic volatile organic compounds and contribute significantly to the production of tropospheric ozone and secondary organic aerosol (SOA). Four toluene and four 1,2,4-trimethylbenzene (1,2,4-TMB) photooxidation experiments were performed in an environmental chamber under relevant polluted conditions (NO ~ 10ppb). An extensive suite of instrumentation including two proton-transfer-reaction mass spectrometers (PTR-MS) and two chemical ionisation mass spectrometers ( CIMS and I CIMS) allowed for quantification of reactive carbon in multiple generations of hydroxyl radical (OH)-initiated oxidation. Oxidation of both species produces ring-retaining products such as cresols, benzaldehydes, and bicyclic intermediate compounds, as well as ring-scission products such as epoxides and dicarbonyls. We show that the oxidation of bicyclic intermediate products leads to the formation of compounds with high oxygen content (an O : C ratio of up to 1.1). These compounds, previously identified as highly oxygenated molecules (HOMs), are produced by more than one pathway with differing numbers of reaction steps with OH, including both auto-oxidation and phenolic pathways. We report the elemental composition of these compounds formed under relevant urban high-NO conditions. We show that ring-retaining products for these two precursors are more diverse and abundant than predicted by current mechanisms. We present the speciated elemental composition of SOA for both precursors and confirm that highly oxygenated products make up a significant fraction of SOA. Ring-scission products are also detected in both the gas and particle phases, and their yields and speciation generally agree with the kinetic model prediction.
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http://dx.doi.org/10.5194/acp-19-15117-2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7133713PMC
December 2019

Total Synthesis of Herquline B and C.

J Am Chem Soc 2019 01 28;141(1):25-28. Epub 2018 Dec 28.

Department of Chemistry and Biochemistry , Baylor University , One Bear Place 97348 , Waco , Texas 76798 , United States.

The total syntheses of (-)-herquline B (2) and a heretofore-unrecognized congener, (+)-herquline C (3), are described. The syntheses require 14 and 13 steps, respectively, and feature a key oxazoline reduction that sets the stage for piperazine construction.
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http://dx.doi.org/10.1021/jacs.8b10212DOI Listing
January 2019

It takes a village to raise awareness of and to address surface contamination of hazardous drugs.

J Oncol Pharm Pract 2017 10 9;23(7):558-560. Epub 2017 Aug 9.

1 Eshelman School of Pharmacy, University of North Carolina (UNC), Chapel Hill, NC, USA.

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http://dx.doi.org/10.1177/1078155217724650DOI Listing
October 2017

Enrichment of Saccharides and Divalent Cations in Sea Spray Aerosol During Two Phytoplankton Blooms.

Environ Sci Technol 2016 11 21;50(21):11511-11520. Epub 2016 Oct 21.

Department of Chemistry, University of Iowa , Iowa City, Iowa 52242, United States.

Sea spray aerosol (SSA) is a globally important source of particulate matter. A mesocosm study was performed to determine the relative enrichment of saccharides and inorganic ions in nascent fine (PM) and coarse (PM) SSA and the sea surface microlayer (SSML) relative to bulk seawater. Saccharides comprise a significant fraction of organic matter in fine and coarse SSA (11 and 27%, respectively). Relative to sodium, individual saccharides were enriched 14-1314-fold in fine SSA, 3-138-fold in coarse SSA, but only up to 1.0-16.2-fold in SSML. Enrichments in SSML were attributed to rising bubbles that scavenge surface-active species from seawater, while further enrichment in fine SSA likely derives from bubble films. Mean enrichment factors for major ions demonstrated significant enrichment in fine SSA for potassium (1.3), magnesium (1.4), and calcium (1.7), likely because of their interactions with organic matter. Consequently, fine SSA develops a salt profile significantly different from that of seawater. Maximal enrichments of saccharides and ions coincided with the second of two phytoplankton blooms, signifying the influence of ocean biology on selective mass transfer across the ocean-air interface.
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http://dx.doi.org/10.1021/acs.est.6b02988DOI Listing
November 2016

Noninvasive Facial Rejuvenation. Part 2: Physician-Directed-Neuromodulators and Fillers.

Semin Plast Surg 2016 Aug;30(3):134-42

Nigro Dermatology Group, Houston, Texas.

A proper knowledge of noninvasive facial rejuvenation is integral to the practice of a cosmetic surgeon. Noninvasive facial rejuvenation can be divided into patient- versus physician-directed modalities. Patient-directed facial rejuvenation combines the use of facial products such as sunscreen, moisturizers, retinoids, α-hydroxy acids, and various antioxidants to both maintain youthful skin as well as rejuvenate damaged skin. Physicians may recommend and often prescribe certain products, but patients are in control with this type of facial rejuvenation. On the other hand, physician-directed facial rejuvenation entails modalities that require direct physician involvement, such as neuromodulators, filler injections, laser resurfacing, microdermabrasion, and chemical peels. With the successful integration of each of these modalities, a complete facial regimen can be established and patient satisfaction can be maximized. This article is the second in a three-part series describing noninvasive facial rejuvenation. Here the authors discuss neuromodulators and fillers in detail, focusing on indications for use, techniques, and common side effects.
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http://dx.doi.org/10.1055/s-0036-1584819DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961509PMC
August 2016

Update on Postsurgical Scar Management.

Semin Plast Surg 2016 Aug;30(3):122-8

Division of Plastic Surgery, Baylor College of Medicine, Houston, Texas.

Postoperative scar appearance is often a significant concern among patients, with many seeking advice from their surgeons regarding scar minimization. Numerous products are available that claim to decrease postoperative scar formation and improve wound healing. These products attempt to create an ideal environment for wound healing by targeting the three phases of wound healing: inflammation, proliferation, and remodeling. With that said, preoperative interventions, such as lifestyle modifications and optimization of medical comorbidities, and intraoperative interventions, such as adherence to meticulous operative techniques, are equally important for ideal scarring. In this article, the authors review the available options in postoperative scar management, addressing the benefits of multimodal perioperative intervention. Although numerous treatments exist, no single modality has been proven superior over others. Therefore, each patient should receive a personalized treatment regimen to optimize scar management.
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http://dx.doi.org/10.1055/s-0036-1584824DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961501PMC
August 2016

Common Pediatric Skin Lesions: A Comprehensive Review of the Current Literature.

Semin Plast Surg 2016 Aug;30(3):91-7

Department of Dermatology, Baylor College of Medicine, Houston, Texas.

The timely diagnosis and treatment of dermatologic disease in the pediatric population can be challenging. A basic, yet comprehensive knowledge of common lesions is essential for a successful practice in plastic surgery. In this article, the authors describe vascular, cystic, and pigmented cutaneous lesions that are commonly encountered in the pediatric population. Epidemiology, pathogenesis, clinical course, and management options are discussed for each.
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http://dx.doi.org/10.1055/s-0036-1584822DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4961505PMC
August 2016

Microbial Control of Sea Spray Aerosol Composition: A Tale of Two Blooms.

ACS Cent Sci 2015 Jun 18;1(3):124-31. Epub 2015 May 18.

Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, United States.

With the oceans covering 71% of the Earth, sea spray aerosol (SSA) particles profoundly impact climate through their ability to scatter solar radiation and serve as seeds for cloud formation. The climate properties can change when sea salt particles become mixed with insoluble organic material formed in ocean regions with phytoplankton blooms. Currently, the extent to which SSA chemical composition and climate properties are altered by biological processes in the ocean is uncertain. To better understand the factors controlling SSA composition, we carried out a mesocosm study in an isolated ocean-atmosphere facility containing 3,400 gallons of natural seawater. Over the course of the study, two successive phytoplankton blooms resulted in SSA with vastly different composition and properties. During the first bloom, aliphatic-rich organics were enhanced in submicron SSA and tracked the abundance of phytoplankton as indicated by chlorophyll-a concentrations. In contrast, the second bloom showed no enhancement of organic species in submicron particles. A concurrent increase in ice nucleating SSA particles was also observed only during the first bloom. Analysis of the temporal variability in the concentration of aliphatic-rich organic species, using a kinetic model, suggests that the observed enhancement in SSA organic content is set by a delicate balance between the rate of phytoplankton primary production of labile lipids and enzymatic induced degradation. This study establishes a mechanistic framework indicating that biological processes in the ocean and SSA chemical composition are coupled not simply by ocean chlorophyll-a concentrations, but are modulated by microbial degradation processes. This work provides unique insight into the biological, chemical, and physical processes that control SSA chemical composition, that when properly accounted for may explain the observed differences in SSA composition between field studies.
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http://dx.doi.org/10.1021/acscentsci.5b00148DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827658PMC
June 2015

Etiology, Prevention, and Management of Infectious Complications of Dermal Fillers.

Semin Plast Surg 2016 May;30(2):83-6

Division of Plastic and Reconstructive Surgery, Baylor College of Medicine, Houston, Texas.

The demand for aesthetic augmentation with soft tissue fillers has greatly increased in recent years and has led to an expansion in the number of products available. Unfortunately, an increase in adverse events has followed. These can be categorized into early, late, and delayed. Early infectious complications generally present as a localized skin infection, cellulitis, or abscess. Fillers can also serve as a focus for chronic infection, which is associated with the development of foreign body granulomas, a late complication. Bacterial colonization and indolent infections of the filler site can lead to biofilms that are extremely difficult to treat. Therefore, it is important to focus on prevention through eliciting a thorough patient history including an injection history, practicing sterile technique, and minimizing tissue trauma. Looking forward, much can be done to curtail complication rates. Early teaching and training, a central recording registry for complications, and a standardized filler passport for patients are suggested.
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http://dx.doi.org/10.1055/s-0036-1580734DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4856531PMC
May 2016

Treatment of Infected Facial Implants.

Semin Plast Surg 2016 May;30(2):78-82

Division of Plastic and Reconstructive Surgery, Baylor College of Medicine, Houston, Texas.

Alloplastic facial implants have a wide range of uses to achieve the appropriate facial contour. A variety of materials such as metals, polymers, ceramics and synthetic injectable fillers are available to the reconstructive and aesthetic surgeon. Besides choosing the right surgical technique and the adequate material, the surgeon must be prepared to treat complications. Infection is an uncommon but serious complication that can cause displeasing consequences for the patient. There are few references in literature regarding treatment and management of facial implant-related infections. This study aims to discuss the role of biofilm in predisposing alloplastic materials to infection, to provide a review of literature, to describe our own institutional experience, and to define a patient care pathway for facial implant-associated infection.
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http://dx.doi.org/10.1055/s-0036-1580727DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4856534PMC
May 2016

Development and evaluation of a novel product to remove surface contamination of hazardous drugs.

J Oncol Pharm Pract 2017 Mar 9;23(2):103-115. Epub 2016 Jul 9.

3 University of North Carolina (UNC) Eshelman School of Pharmacy, Chapel Hill, NC, USA.

Background Even while following best practices, surface exposures of hazardous drugs (HDs) are high and numerous. Thus, it is important to develop new products to reduce the surface contamination of HDs. Hazardous Drug Clean (HDClean™) was developed to decontaminate and remove HDs from various types of surfaces and overcome the problems associated with other cleaning products. Methods HDClean was evaluated to remove mock surface exposures of HDs (docetaxel, paclitaxel, ifosfamide, cyclophosphamide, 5-FU, and cisplatin) from various types of surfaces. In two separate cancer centers, studies were performed to evaluate HDClean in reducing surface contamination of HDs in the pharmacy departments where no closed system transfer device (CSTD) was used. In a third cancer center, studies were performed comparing the effectiveness of a CSTD + Surface Safe compared with CSTD + HDClean to remove HDs. Results HDClean was able to completely remove mock exposures of a wide range of HDs from various surfaces (4 and 8 sq ft areas). Daily use of HDClean was equal to or more effective in reducing surface contamination of HDs in two pharmacies compared with a CSTD. HDClean was significantly more effective in removing HDs, especially cisplatin, compared with Surface Safe and does not have the problems associated with decontamination solutions that contain sodium hypochlorite. Conclusion These studies support HDClean as an effective decontaminating product, that HDClean is more effective than Surface Safe in removing HDs and is equal to or more effective than CSTD in controlling HD surface exposures.
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http://dx.doi.org/10.1177/1078155215621151DOI Listing
March 2017

Vascular malformations: a review.

Semin Plast Surg 2014 May;28(2):58-63

Division of Plastic Surgery, Baylor College of Medicine, Houston, Texas.

Identification and treatment of vascular malformations is a challenging endeavor for physicians, especially given the great concern and anxiety created for patients and their families. The goal of this article is to provide a review of vascular malformations, organized by subtype, including capillary, venous, lymphatic and arteriovenous malformations. Only by developing a clear understanding of the clinical aspects, diagnostic tools, imaging modalities, and options for intervention will appropriate care be provided and results maximized.
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http://dx.doi.org/10.1055/s-0034-1376263DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4078214PMC
May 2014

Psoas syndrome: a frequently missed diagnosis.

J Am Osteopath Assoc 2012 Aug;112(8):522-8

Department of Family Medicine, Kansas City University of Medicine and Biosciences' College of Osteopathic Medicine, 1750 Independence Ave, SEP 354, Kansas City, MO 64106-1453, USA.

Psoas syndrome is an easily missed diagnosis. However, it is important to consider this condition as part of the differential diagnosis for patients presenting with low back pain--particularly for osteopathic physicians, because patients may view these practitioners as experts in musculoskeletal conditions. The authors describe the case of a 48-year-old man with a 6-month history of low back pain that had been attributed to "weak core muscles." The diagnosis of psoas syndrome was initially overlooked in this patient. After the correct diagnosis was made, he was treated by an osteopathic physician using osteopathic manipulative treatment, in conjunction with at-home stretches between office treatments. At his 1-month follow-up appointment, he demonstrated continued improvement of symptoms and a desire for further osteopathic manipulative treatment.
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http://dx.doi.org/10.7556/jaoa.2012.112.8.522DOI Listing
August 2012

Facial fat compartments: a guide to filler placement.

Semin Plast Surg 2009 Nov;23(4):283-7

Division of Plastic Surgery, Baylor College of Medicine, Texas Children's Hospital, Houston, Texas.

Advances in anatomic understanding are frequently the basis upon which surgical techniques are advanced and refined. Recent anatomic studies of the superficial tissues of the face have led to an increased understanding of the compartmentalized nature of the subcutaneous fat. This report provides a review of the locations and characteristics of the facial fat compartments and provides examples of how this knowledge can be used clinically, specifically with regard to soft tissue fillers.
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http://dx.doi.org/10.1055/s-0029-1242181DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2884915PMC
November 2009

Sunscreens: evolving aspects of sun protection.

J Pediatr Health Care 2010 Sep-Oct;24(5):343-6. Epub 2010 Mar 15.

Division of Plastic Surgery, Baylor College of Medicine, Houston, TX, USA.

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http://dx.doi.org/10.1016/j.pedhc.2010.01.002DOI Listing
December 2010

Important lessons in opioid selection.

Authors:
Joshua M Cox

Am J Health Syst Pharm 2008 Sep;65(17):1599-600; author reply 1600-1

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http://dx.doi.org/10.2146/ajhp080035DOI Listing
September 2008

Chronic obstructive pulmonary disease and dyspnea: a Pandora's box of comorbid symptoms?

Am J Hosp Palliat Care 2003 May-Jun;20(3):179-81

University of Florida, College of Pharmacy, Gainesville, Florida, USA.

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http://dx.doi.org/10.1177/104990910302000305DOI Listing
July 2003