Publications by authors named "Smit Shah"

40 Publications

purulent pericarditis in an immunocompetent individual.

J Community Hosp Intern Med Perspect 2021 Jan 26;11(1):96-98. Epub 2021 Jan 26.

Tower Health System, Reading Hospital, Reading, PA, USA.

Purulent pericarditis is a rare bacterial illness in the post-antibiotic era that is defined as pericardial infection with gross or microscopic purulence in the pericardium. Common causes include nosocomial bloodstream infections, direct spread through thoracic surgery, or immunosuppression. We present a case of a 66-year-old male with a history of mantle cell lymphoma status post chemotherapy, completed about 4 years before presentation, in general, good health presented with acute typical chest pain associated with dyspnea on exertion. 12-lead EKG demonstrated ST elevations in anterolateral and lateral leads. Patient was initially being managed as Acute Coronary Syndrome, though, preliminary bedside echocardiogram demonstrated a large pericardial effusion with pretamponade physiology, which was confirmed with a STAT transthoracic echocardiogram. He underwent an emergent pericardial window which drained 350-400 ml of yellow murky pericardial fluid. Blood cultures and pericardial fluid cultures grew Haemophilus (H. ). Upon further history taking, patient revealed experiencing upper respiratory symptoms and being diagnosed with pansinusitis 2 months before his admission. He was treated with IV ceftriaxone for 4 weeks from the day of negative blood cultures. H. upper respiratory infection is usually seen in the unvaccinated pediatric population, or in immunocompromised individuals; however, few cases in vaccinated adults have been reported, as in the above case. Sequalae from H. infection is usually limited to upper respiratory symptoms and mastoiditis, but rarely, pericarditis could occur. It is important to include pericarditis in the differential for chest pain in a patient with a recent history of upper respiratory symptoms. Pericarditis is a rare but potentially serious complication of recent upper respiratory tract infection, and needs to be promptly identified and treated to avoid further morbidity.
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http://dx.doi.org/10.1080/20009666.2020.1835213DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7850390PMC
January 2021

Porencephalic cyst after endoscopic third ventriculostomy and Ommaya reservoir placement: case report and review of the literature.

Childs Nerv Syst 2021 Jan 13. Epub 2021 Jan 13.

Department of Neurosurgery, Westchester Medical Center, New York Medical College, 100 Woods Rd, Suite 1325-1333, Valhalla, NY, 10595, USA.

Background: A 13-year-old female patient was diagnosed with a tectal glioma (TG), a subgroup of astrocytoma that can result in obstructive hydrocephalus secondary to aqueductal stenosis. Endoscopic third ventriculostomy (ETV) is used to treat this type of hydrocephalus with a good success rate. Our institution performs ETV and Ommaya reservoir (OR) placement in these cases. The OR allows measurement of intracranial pressure (ICP) and cerebrospinal fluid (CSF) access and a method for performing ventricular dye studies to evaluate third ventricular stoma (TVS) patency. In this case, a porencephalic cyst (PC) developed around the OR's ventricular catheter (OVC) two and a half months after surgery.

Conclusion: The PC is thought to have developed in association with TVS stoma closure and resolved after ETV revision.
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http://dx.doi.org/10.1007/s00381-021-05042-wDOI Listing
January 2021

Disease Response to Pazopanib in Follicular Dendritic Cell Sarcoma.

Case Rep Oncol 2020 Sep-Dec;13(3):1131-1135. Epub 2020 Sep 21.

Department of Hematology/Oncology, Reading Hospital, Tower Health, West Reading, Pennsylvania, USA.

Follicular dendritic cell sarcoma (FDCS) is a rare sarcoma, which commonly presents as a slow-growing, painless mass. There are only a few hundred reported FDCS cases, and the role for adjuvant chemo- or radiation therapy has not been established. Choosing an appropriate therapy in disseminated disease can therefore be challenging. A 26-year-old patient with FDCS was admitted with dyspnea, fever, and night sweats. He was found to have a large right hemothorax with compressive atelectasis on initial imaging. CT of the chest revealed multiple bilateral lung and pleural nodules with associated bilateral hilar adenopathy, a hypodense mass within the right hemithorax, and necrotic right external iliac and inguinal nodes. Inguinal node biopsy diagnosed FDCS. The patient was initially treated with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. Gemcitabine/Taxotere was given as second-line therapy and pembrolizumab as third-line therapy, with continued disease progression after 2 cycles of both regimens. The patient was switched to fourth-line therapy with pazopanib and had a partial response for 9 months. This case illustrates a successful FDCS treatment with pazopanib. Due to the rarity of FDCS, where large studies comparing treatment approaches are not available, recommendations for optimal treatment are not well defined. This case is in support of growing evidence suggesting that FDCS responds to systemic therapies that are used for soft tissue sarcoma, such as pazopanib.
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http://dx.doi.org/10.1159/000509771DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7548949PMC
September 2020

Evaluating the Safety and Efficacy of Various Endovascular Approaches for Treatment of Infectious Intracranial Aneurysms: A Systematic Review.

World Neurosurg 2020 12 17;144:293-298.e15. Epub 2020 Aug 17.

Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA. Electronic address:

Objective: A review of endovascular cerebral mycotic aneurysm treatment with Onyx liquid embolic, N-butyl-2-cyanoacrylate (NBCA), or coil embolization has not been reported. The authors conduct a systematic review on endovascular treatment methods of mycotic aneurysms.

Methods: A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986 and 2020. All studies assessing outcomes related to endovascular Onyx embolization, NBCA embolization, or coiling were included.

Results: A total of 73 studies were ultimately selected including 180 (67% male) patients comprising 243 aneurysms treated endovascularly. The mean age was 38.2 ± 17.6 years, and the most common symptom on presentation was headache (31%). Most aneurysms were located on the middle cerebral artery (52.5%), and over half presented with rupture (53.8%). Coiling was the most commonly employed technique (50.4%), and obliteration rates were comparable across coiling, NBCA, and Onyx (99.1%, 100%, 100%, respectively). Complication rates were also comparable (4.3% vs. 15.2% vs. 8.1%).

Conclusions: Embolization for infectious intracranial aneurysm appears to be an effective treatment option for mycotic aneurysms. Embolization rates were comparable among coiling, NBCA, and Onyx embolization. Noninferiority among these modalities cannot be demonstrated given the retrospective nature of this review, evolution of endovascular techniques over the years, and changes in treatment paradigms in the past 2 decades. Ideally, further prospective research will be necessary to find which treatment method offers the lowest complication rates and the best outcomes for patients with mycotic aneurysms.
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http://dx.doi.org/10.1016/j.wneu.2020.07.228DOI Listing
December 2020

Carbon nanotubes affect early growth, flowering time and phytohormones in tomato.

Chemosphere 2020 Oct 11;256:127042. Epub 2020 May 11.

Department of Environmental Toxicology, The Institute for Environmental and Human Health, Texas Tech University, P.O. Box 41163, Lubbock, Texas, 79409, USA. Electronic address:

Carbon nanotube (CNT) applications are increasing in consumer products, including agriculture devices, making them an important contaminant to study in the field of plant nanotoxicology. Several studies have observed the uptake and effects of CNTs in plants. However, in other studies differing results were observed on growth and physiology depending on the plant species and type of CNT. This study focused on the effects of CNTs on plant phenotype with growth, time to flowering, fruiting time as endpoints, and physiology, through amino acid and phytohormone content, in tomato after exposure to multiple types of CNTs. Plants grown in CNT-contaminated soil exhibited a delay in early growth and flowering (especially in treatments of 1 mg/kg multi-walled nanotubes (MWNTs), 10 mg/kg MWNTs, and 1 mg/kg MWNTs-COOH). However, CNTs did not affect plant growth or height later in the life cycle. No significant differences in abscisic acid (ABA) and citrulline content were observed between the treated and control plants. However, single-walled nanotube (SWNT) exposure significantly increased salicylic acid (SA) content in tomato. These results suggest that SWNTs may elicit a stress response in tomatoes. Results from this study offer more insight into how plants respond and acclimate to CNTs. These results will lead to a better understanding of CNT impact on plant phenotype and physiology.
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http://dx.doi.org/10.1016/j.chemosphere.2020.127042DOI Listing
October 2020

Mobile Myxopapillary Ependymoma with Associated Filum Terminale Cyst.

World Neurosurg 2020 07 25;139:337-342. Epub 2020 Apr 25.

Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA.

Background: Intradural ependymal cysts are benign, fluid-filled cysts usually situated along the ventral surface of the spinal cord. There are previous reports of 19 intradural cysts in the literature, including one cyst of the filum terminale. Here, we report for the first time the presence of a radiographically occult filum terminale cyst associated with a myxopapillary ependymoma. We propose that mobility of the tumor may provide indirect evidence of the presence of a cyst.

Case Description: A 65-year-old male patient presented with a homogenously enhancing ovoid mass measuring 25 mm × 10 mm within the thecal sac at the L3 through L4 levels. Repeat magnetic resonance imaging demonstrated migration of the tumor 12 mm rostrally. Following the L2 through L4 laminectomy and resection of the intradural tumor, we identified a filum terminale ependymal cyst superior to the tumor, which was also resected.

Conclusions: Ependymal cysts associated with spinal tumors are rare and may be radiographically occult. The change in cyst size may explain tumor mobility. Complete resection of the cyst and histopathologic analysis is recommended to differentiate between ependymal cyst and cystic tumor tissue.
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http://dx.doi.org/10.1016/j.wneu.2020.04.095DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7453488PMC
July 2020

Comparison of Nanoarchitecture to Porous Media Diffusion Models in Reduced Graphene Oxide/Aramid Nanofiber Electrodes for Supercapacitors.

ACS Nano 2020 May 6;14(5):5314-5323. Epub 2020 May 6.

Structural electrodes made of reduced graphene oxide (rGO) and aramid nanofiber (ANF) are promising candidates for future structural supercapacitors. In this study, the influence of nanoarchitecture on the effective ionic diffusivity, porosity, and tortuosity in rGO/ANF structural electrodes is investigated through multiphysics computational modeling. Two specific nanoarchitectures, namely, "house of cards" and "layered" structures, are evaluated. The results obtained from nanoarchitecture computational modeling are compared to the porous media approach and show that the widely used porous electrode theories, such as Bruggeman or Millington-Quirk relations, overestimate the effective diffusion coefficient. Also, the results from nanoarchitecture modeling are validated with experimental measurements obtained from electrochemical impedance spectroscopy and cyclic voltammetry. The effective diffusion coefficients obtained from nanoarchitectural modeling show better agreement with experimental measurements. Evaluation of microscopic properties such as porosity, tortuosity, and effective diffusivity through both experiment and simulation is essential to understand the material behavior and to improve its performance.
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http://dx.doi.org/10.1021/acsnano.9b07116DOI Listing
May 2020

Dielectric Barrier Discharge Applicator for Heating Carbon Nanotube-Loaded Interfaces and Enhancing 3D-Printed Bond Strength.

Nano Lett 2020 Apr 5;20(4):2310-2315. Epub 2020 Mar 5.

Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States.

Material extrusion (ME) 3D printing is a revolutionary technique for manufacturing thermoplastic parts; however, the printed parts typically suffer from poor interlayer bonding, which causes weak tensile strength in the build direction. Many methods have been proposed to address the mechanical deficiencies of 3D-printed parts, but most fall short of a production-ready solution. Here we report the use of a dielectric barrier discharge (DBD) plasma electrode mounted concentrically around the nozzle of an ME 3D printer for welding of thermoplastic parts. This is the first report of a DBD being used as a non-contact means to induce Joule heating in resistive composite materials. The polymer welding process is accomplished by coupling the DBD with the carbon nanotube-loaded interfaces between the 3D-printed layers. The current passing through the part results in rapid resistive heating of the nanotubes and thermal welding of the interfaces. We show that parts printed with this method have isotropic strength and are equivalent to their injection-molded counterparts.
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http://dx.doi.org/10.1021/acs.nanolett.9b04718DOI Listing
April 2020

Antegrade versus retrograde nailing in humeral shaft fractures: A prospective study.

J Clin Orthop Trauma 2020 Feb 30;11(Suppl 1):S37-S41. Epub 2019 Apr 30.

Consultant Orthopaedic Surgeon at Nanavati Super Speciality Hospital, Mumbai.

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http://dx.doi.org/10.1016/j.jcot.2019.04.020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6978192PMC
February 2020

Translocation, trophic transfer, accumulation and depuration of polystyrene microplastics in Daphnia magna and Pimephales promelas.

Environ Pollut 2020 Apr 10;259:113937. Epub 2020 Jan 10.

Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, United States. Electronic address:

In recent years, reports of plastic debris in the gastrointestinal (GI) tract of fish have been well documented in the scientific literature. This, in turn, increased concerns regarding human health exposure to microplastics through the consumption of contaminated fish. Most of the available research regarding microplastic toxicity has focused on marine organisms through direct feeding or waterborne exposures at the individual level. However, little is known about the trophic transfer of microplastics through the aquatic food chain. Freshwater zooplankton Daphnia magna (hereafter Daphnia), and the fathead minnow Pimephales promelas (FHM), are well-known model species used in standard toxicological studies and ecological risk assessments that provide a simple model for trophic transfer. The aim of this study was to assess the tissue translocation, trophic transfer, and depuration of two concentrations (20 and 2000-part ml) of 6 μm polystyrene (PS) microplastics particles between Daphnia and FHM. Bioconcentration factors (BCF) and bioaccumulation factors (BAF) were determined. Fluorescent microscopy was used to determine the number of particles in the water media and within the organs of both species. Throughout the five days of exposure, PS particles were only found within the GI tract of both species. The BCF for Daphnia was 0.034 ± 0.005 for the low concentration and 0.026 ± 0.006 for the high concentration. The BAF for FHM was 0.094 ± 0.037 for the low concentration and 0.205 ± 0.051 for the high concentration. Between 72 and 96 h after exposure all microplastic particles were depurated from both species. The presence of food had a significant effect on the depuration of microplastic particles from Daphnia but not for FHM. Based on the low BCF and BAF values for both species, rapid depuration rates, and null translocation of microplastic particles to organs and tissues from the GI tract, there is a low probability that microplastics will bioconcentrate and bioaccumulate under environmental conditions.
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http://dx.doi.org/10.1016/j.envpol.2020.113937DOI Listing
April 2020

The epichaperome is a mediator of toxic hippocampal stress and leads to protein connectivity-based dysfunction.

Nat Commun 2020 01 16;11(1):319. Epub 2020 Jan 16.

Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.

Optimal functioning of neuronal networks is critical to the complex cognitive processes of memory and executive function that deteriorate in Alzheimer's disease (AD). Here we use cellular and animal models as well as human biospecimens to show that AD-related stressors mediate global disturbances in dynamic intra- and inter-neuronal networks through pathologic rewiring of the chaperome system into epichaperomes. These structures provide the backbone upon which proteome-wide connectivity, and in turn, protein networks become disturbed and ultimately dysfunctional. We introduce the term protein connectivity-based dysfunction (PCBD) to define this mechanism. Among most sensitive to PCBD are pathways with key roles in synaptic plasticity. We show at cellular and target organ levels that network connectivity and functional imbalances revert to normal levels upon epichaperome inhibition. In conclusion, we provide proof-of-principle to propose AD is a PCBDopathy, a disease of proteome-wide connectivity defects mediated by maladaptive epichaperomes.
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http://dx.doi.org/10.1038/s41467-019-14082-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6965647PMC
January 2020

Medicaid payer status and other factors associated with hospital length of stay in patients undergoing primary lumbar spine surgery.

Clin Neurol Neurosurg 2020 01 24;188:105570. Epub 2019 Oct 24.

Department of Neurosurgery, Westchester Medical Center, New York Medical College, Valhalla, NY 10595, USA. Electronic address:

Objective: The Medicaid patient population and health care costs for spine surgeries among these patients have increased since 2010. Hospital length of stay (LOS) contributes appreciably to hospital costs for patients undergoing primary lumbar spine surgery (PLSS). The aim of this study was to identify independent risk factors for increased LOS in patients undergoing PLSS.

Patients And Methods: In a single-center retrospective study, we reviewed demographic and clinical data from electronic medical records for 181 consecutive adult patients who underwent PLSS involving 1-3 levels from July 2014 to July 2017. We performed regression analyses to identify independent risk factors for increased LOS and to quantify their effects as percent changes in LOS.

Results: Among 181 patients who underwent PLSS, the mean LOS was 3.57 days. Based on the Charlson Comorbidity Index (CCI) and American Society of Anesthesiologist (ASA) classification, patients with Medicaid insurance were healthier than non-Medicaid patients (mean CCI: 0.34 versus 0.65; p = 0.041, ASA: 1.71 versus 1.91; p = 0.046) yet Medicaid patients had a longer LOS compared with non-Medicaid patients (mean LOS: 4.03 versus 3.30 days; p = 0.047). There was no significant difference in discharge disposition between Medicaid and non-Medicaid patients (Home = 82.35 % versus 79.65 %; p = 0.855). Medicaid patients also had significantly less spinal levels involved in their surgery (1.44 versus 1.67; p = 0.027). Multivariable regression modeling identified independent risk factors positively associated with increased LOS as age (+1.0 % per year; p = 0.007), Medicaid insurance status (+28.7 %; p = 0.007), and CCI (10.1 % per increment in CCI; p = 0.030). Fusion surgery also was an independent risk factor for increased LOS when compared with laminectomy (-54.1 %; p < 0.001) or discectomy (-51.3 %; p < 0.001).

Conclusions: Increasing age, Medicaid insurance status, higher CCI, and fusion surgery were independently associated with increased LOS after PLSS. This information is useful for preoperative patient counseling, shared decision-making, and risk stratification and may help to further ongoing discussion regarding contributors to rising health care costs. Findings of increased LOS among Medicaid patients will help direct efforts to identify factors that contribute to this health care expense.
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http://dx.doi.org/10.1016/j.clineuro.2019.105570DOI Listing
January 2020

Aramid nanofiber-reinforced three-dimensional graphene hydrogels for supercapacitor electrodes.

J Colloid Interface Sci 2020 Feb 26;560:581-588. Epub 2019 Oct 26.

Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States; Department of Materials Science and Engineering, Texas A&M University, College Station, TX, United States. Electronic address:

Hypothesis: Self-assembled graphene hydrogels are notable in the field of electrochemical energy storage for their unique combination of excellent specific surface area, high porosity, and electrically conductive continuous network. However, graphene hydrogels suffer from poor mechanical integrity compared to layered architectures like graphene buckypapers, limiting their applications in practical devices. We propose the use of high strength, Kevlar®-derived polymeric nanofillers, aramid nanofibers (ANFs) as structural fillers to enhance graphene hydrogel's shear modulus in the context of multifunctional (mechanical and electrochemical) architectures.

Experiments: Graphene hydrogels are fabricated using sol-gel self-assembly of graphene oxide (GO) nanosheets in presence of ammonium hydroxide. Colloidal dispersion of ANFs and GO are integrated using a novel combination of solvent exchange and dialysis approach to fabricate GO-ANF hydrogels with 0-15 wt.% of ANFs loading (dry weight basis). Shear modulus and electrochemical properties of resulting hydrogel composites are evaluated using rheology and symmetric supercapacitor cell.

Findings: The addition of 2 wt.% ANFs resulted in an 80% improvement in shear modulus compared to neat graphene hydrogel. Addition of ANFs resulted in gradual reduction of specific capacitance, with the specific capacitance of 190 F/g for neat graphene hydrogel, reducing to 128 F/g for an ANF loading of 15 wt.% (dry weight basis). This work shows the broader concept that adding high-strength nanofibers to a nanomaterial gel can add reinforcement provided that the gelation process itself is not disrupted.
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http://dx.doi.org/10.1016/j.jcis.2019.10.066DOI Listing
February 2020

Paradigms for Precision Medicine in Epichaperome Cancer Therapy.

Cancer Cell 2019 11 24;36(5):559-573.e7. Epub 2019 Oct 24.

Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Program in Molecular Pharmacology, Sloan Kettering Institute, New York, NY 10065, USA.

Alterations in protein-protein interaction networks are at the core of malignant transformation but have yet to be translated into appropriate diagnostic tools. We make use of the kinetic selectivity properties of an imaging probe to visualize and measure the epichaperome, a pathologic protein-protein interaction network. We are able to assay and image epichaperome networks in cancer and their engagement by inhibitor in patients' tumors at single-lesion resolution in real time, and demonstrate that quantitative evaluation at the level of individual tumors can be used to optimize dose and schedule selection. We thus provide preclinical and clinical evidence in the use of this theranostic platform for precision medicine targeting of the aberrant properties of protein networks.
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http://dx.doi.org/10.1016/j.ccell.2019.09.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6996250PMC
November 2019

The Origins of Eponymous Aneurysm Clips: A Review.

World Neurosurg 2020 Feb 19;134:518-531. Epub 2019 Sep 19.

Department of Neurosurgery, Rutgers-Robert Wood Johnson Medical School & University Hospital, New Brunswick, New Jersey, USA. Electronic address:

Aneurysm clips are indispensable tools in the armamentarium of vascular neurosurgeons. The history of the development of aneurysm clips is witness to ingenuity and tenacity in treating a potentially devastating disease. Few know the stories of their innovators and the inspiration behind their designs. Hence, we present this historical vignette in an attempt to shed more light on the pioneers who shaped the evolution of aneurysm clips as we know them. A comprehensive literature search was performed using PubMed, Google Scholar, Google Books, and library historical archives, as well as personal communications with relatives, colleagues, and institutions of the surgeon-designers. We present the following aneurysm clip innovators and chronicle their biographies and contributions: Herbert Olivecrona (1891-1980), Frank Mayfield (1908-1991), Charles Drake (1920-1998), Joseph McFadden (1920-present), Thoralf Sundt Jr. (1930-1992), William M. Lougheed (1923-2004), William B. Scoville (1906-1984), Milton D. Heifetz (1921-2015), Gazi Yaşargil (1925-present), Kenichiro Sugita (1932-1994), and Robert Spetzler (1944-present). Although this compilation of eponymous clips is by no means complete, we hope that it provides an informative historical perspective and an inspiration for aspiring neurosurgeons. The history of aneurysm surgery, an entity once deemed inoperable, teaches us the importance of innovation in medicine.
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http://dx.doi.org/10.1016/j.wneu.2019.09.061DOI Listing
February 2020

Traumatic Occipitocervical Distraction Injuries in Children: A Systematic Review.

Pediatr Neurosurg 2019 7;54(2):75-84. Epub 2019 Mar 7.

Department of Neurosurgery, New Jersey Medical School and Robert Wood Johnson Medical School, Rutgers University, Nashville, Tennessee, USA.

Background: Occipitocervical distraction injuries (OCDI) in children occur on a wide spectrum of severity, and decisions about treatment suffer from a lack of rigorous guidelines and significant inter-institutional variability. While clear cases of frank atlanto-occipital dislocation (AOD) are treated with surgical stabilization, the approach for less severe cases of OCDI is not standardized. These patients require a careful assessment of both radiographic and clinical criteria, as part of a complex risk-benefit analysis, to establish whether occipitocervical fusion (OCF) is indicated. Here, we performed a systematic review of the literature that describes traumatic OCDI in children < 18 years of age.

Summary: We performed a systematic review, according to PRISMA guidelines, of children < 18 years of age presenting with traumatic etiologies of OCDI. We searched PubMed to identify papers congruent with these criteria. Exclusion criteria included (1) reports on atraumatic causes of OCDI and (2) studies with insufficient clinical and radiographic details on individual patients. We identified 16 reports describing a total of 144 patients treated for pediatric traumatic OCDI. Based on the synthesis of these findings and the collective experience of the authors, we present the demographic, clinical, and radiographic factors that underlie OC instability, which we hope will serve as components of a grading system in the future. We considered various clinical and radiographic findings including: (1) the mechanism of injury, (2) the patient's age, (3) CT/CT angiography of head and neck findings and parameters, (4) MRI findings, and (5) neurological exam, for the purpose of determining the severity of the OCDI and offering treatment guidelines based on the summative risk of underlying OC instability. Key Messages: OCDI is a potentially devastating injury, especially in children. Although missing the diagnosis can have potentially catastrophic consequences, reverting to surgical fixation in less severe cases can subject children to unnecessary operative risk and permanently reduce their range of motion. After reviewing all the available reports of pediatric traumatic OCDI in the neurosurgical literature, we propose an outline of clinical and radiographic factors influencing underlying OC instability that could be incorporated into a grading scale to guide treatment. We hope this study stimulates discussion on the standardization of treatment for pediatric OCDI.
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http://dx.doi.org/10.1159/000496832DOI Listing
April 2019

An APETALA1 ortholog affects plant architecture and seed yield component in oilseed rape (Brassica napus L.).

BMC Plant Biol 2018 Dec 29;18(1):380. Epub 2018 Dec 29.

Plant Breeding Institute, Christian-Albrechts-University of Kiel, Olshausenstr. 40, 24098, Kiel, Germany.

Background: Increasing the productivity of rapeseed as one of the widely cultivated oil crops in the world is of upmost importance. As flowering time and plant architecture play a key role in the regulation of rapeseed yield, understanding the genetic mechanism underlying these traits can boost the rapeseed breeding. Meristem identity genes are known to have pleiotropic effects on plant architecture and seed yield in various crops. To understand the function of one of the meristem identity genes, APETALA1 (AP1) in rapeseed, we performed phenotypic analysis of TILLING mutants under greenhouse conditions. Three stop codon mutant families carrying a mutation in Bna.AP1.A02 paralog were analyzed for different plant architecture and seed yield-related traits.

Results: It was evident that stop codon mutation in the K domain of Bna.AP1.A02 paralog caused significant changes in flower morphology as well as plant architecture related traits like plant height, branch height, and branch number. Furthermore, yield-related traits like seed yield per plant and number of seeds per plants were also significantly altered in the same mutant family. Apart from phenotypic changes, stop codon mutation in K domain of Bna.AP1.A02 paralog also altered the expression of putative downstream target genes like Bna.TFL1 and Bna.FUL in shoot apical meristem (SAM) of rapeseed. Mutant plants carrying stop codon mutations in the COOH domain of Bna.AP1.A02 paralog did not have a significant effect on plant architecture, yield-related traits or the expression of the downstream targets.

Conclusions: We found that Bna.AP1.A02 paralog has pleiotropic effect on plant architecture and yield-related traits in rapeseed. The allele we found in the current study with a beneficial effect on seed yield can be incorporated into rapeseed breeding pool to develop new varieties.
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http://dx.doi.org/10.1186/s12870-018-1606-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6310979PMC
December 2018

Phase I trial of convection-enhanced delivery of IL13-Pseudomonas toxin in children with diffuse intrinsic pontine glioma.

J Neurosurg Pediatr 2018 12;23(3):333-342

6Department of Neurological Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio.

OBJECTIVE In this clinical trial report, the authors analyze safety and infusion distribution of IL13-Pseudomonas exotoxin, an antitumor chimeric molecule, administered via intratumoral convection enhanced delivery (CED) in pediatric patients with diffuse intrinsic pontine glioma (DIPG). METHODS This was a Phase I single-institution, open-label, dose-escalation, safety and tolerability study of IL13-PE38QQR infused via single-catheter CED into 5 pediatric DIPG patients. IL13-PE38QQR was administered to regions of tumor selected by radiographic findings. Two escalating dose levels were evaluated: 0.125 µg/mL in cohort 1 and 0.25 µg/mL in cohort 2. Real-time MRI was performed during intratumoral infusions, and MRI and MR spectroscopy were performed before and after the infusions. Clinical evaluations, including parent-reported quality of life (QOL), were assessed at baseline and 4 weeks post-infusion. RESULTS Direct infusion of brainstem tumor with IL13-PE using the CED technique in patients with DIPG produced temporary arrest of disease progression in 2 of 5 patients, both of whom subsequently received a second infusion. All 5 patients showed signs of disease progression by 12 weeks after initial infusion. Two patients experienced transient cranial nerve deficits and lethargy after infusion, and these deficits resolved with corticosteroid treatment in both cases. No patient had radiographic evidence of acute or long-term treatment toxicity. Parent-reported QOL was consistent with medical outcomes. CONCLUSIONS Even though IL13-PE delivered by CED did not reach the entire MRI-defined tumor volume in any patient, short-term radiographic antitumor effects were observed in 2 of the 5 patients treated. The patients’ performance status did not improve. Drug delivery using multiple catheters may produce improved outcomes. Clinical trial registration no.: NCT00088061 (clinicaltrials.gov) ABBREVIATIONS CED = convection-enhanced delivery; DIPG = diffuse intrinsic pontine glioma; IL-13 = interleukin 13; IL13R = IL-13 receptor; IPI = Impact of Pediatric Illness; KPS = Karnofsky Performance Status; LPS = Lansky Performance Status; MRS = MR spectroscopy; NAA = n-acetyl aspartate; QOL = quality of life; Vd = volume of distribution; Vi = volume of infusion.
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http://dx.doi.org/10.3171/2018.9.PEDS17225DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7266009PMC
December 2018

HSP90-incorporating chaperome networks as biosensor for disease-related pathways in patient-specific midbrain dopamine neurons.

Nat Commun 2018 10 19;9(1):4345. Epub 2018 Oct 19.

The Center for Stem Cell Biology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 256, New York, NY, 10065, USA.

Environmental and genetic risk factors contribute to Parkinson's Disease (PD) pathogenesis and the associated midbrain dopamine (mDA) neuron loss. Here, we identify early PD pathogenic events by developing methodology that utilizes recent innovations in human pluripotent stem cells (hPSC) and chemical sensors of HSP90-incorporating chaperome networks. We show that events triggered by PD-related genetic or toxic stimuli alter the neuronal proteome, thereby altering the stress-specific chaperome networks, which produce changes detected by chemical sensors. Through this method we identify STAT3 and NF-κB signaling activation as examples of genetic stress, and phospho-tyrosine hydroxylase (TH) activation as an example of toxic stress-induced pathways in PD neurons. Importantly, pharmacological inhibition of the stress chaperome network reversed abnormal phospho-STAT3 signaling and phospho-TH-related dopamine levels and rescued PD neuron viability. The use of chemical sensors of chaperome networks on hPSC-derived lineages may present a general strategy to identify molecular events associated with neurodegenerative diseases.
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http://dx.doi.org/10.1038/s41467-018-06486-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6195591PMC
October 2018

High-yield scalable graphene nanosheet production from compressed graphite using electrochemical exfoliation.

Sci Rep 2018 Sep 28;8(1):14525. Epub 2018 Sep 28.

Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA.

Electrochemical exfoliation is a promising bulk method for producing graphene from graphite; in this method, an applied voltage drives ionic species to intercalate into graphite where they form gaseous species that expand and exfoliate individual graphene sheets. However, a number of obstacles have prevented this approach from becoming a feasible production route; the disintegration of the graphite electrode as the method progresses is the chief difficulty. Here we show that if graphite powders are contained and compressed within a permeable and expandable containment system, the graphite powders can be continuously intercalated, expanded, and exfoliated to produce graphene. Our data indicate both high yield (65%) and extraordinarily large lateral size (>30 μm) in the as-produced graphene. We also show that this process is scalable and that graphene yield efficiency depends solely on reactor geometry, graphite compression, and electrolyte transport.
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http://dx.doi.org/10.1038/s41598-018-32741-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162260PMC
September 2018

Effect of Bone Flap Surface Area on Outcomes in Decompressive Hemicraniectomy for Traumatic Brain Injury.

World Neurosurg 2018 Nov 9;119:e922-e927. Epub 2018 Aug 9.

Department of Neurosurgery, New York Medical College, Valhalla, New York, USA.

Background: Decompressive hemicraniectomy to control medically refractory intracranial hypertension and cerebral edema and evacuate mass lesions in traumatic brain injury is a widely accepted treatment paradigm. However, the critical specifications of the bone flap size necessary to control the intracranial pressure (ICP) and provide improved patient outcomes is unknown. We assessed the effect of craniectomy size on the outcomes in surgical decompression for traumatic brain injury.

Methods: From 2003 to 2011, 58 cases of decompressive hemicraniectomy were performed for evacuation of hematoma and treatment of refractory ICP in adult patients with traumatic brain injury. The surface area of the decompressive bone flaps was calculated from the postoperative computed tomography scans and correlated with the ICP and Glasgow Coma Scale scores immediately postoperatively and during long-term follow-up.

Results: Decompressive craniectomy led to a statistically significant continued reduction in the preoperative ICP values (24.5 mm Hg; range, 5-30 mm Hg) compared with the postoperative ICP (16.7 mm Hg; range, 1-30; P = 0.006). However, no significant improvement in the preoperative Glasgow Coma Scale (7.47 mm Hg; range, 3-15; vs. 7.50 mm Hg; range, 3-15; P = 0.96) was observed with hemicraniectomy.

Conclusion: For surface areas of 7000-16,000 mm, size was an independent factor in ICP reduction but not for the overall neurologic outcome.
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http://dx.doi.org/10.1016/j.wneu.2018.08.005DOI Listing
November 2018

Tailored Network Formation in Graphene Oxide Gels.

Langmuir 2018 07 11;34(29):8550-8559. Epub 2018 Jul 11.

Graphene oxide (GO)-based gels are attractive because of their ability to retain individual nanosheet properties in a three-dimensional (3D) bulk material. The final morphology and properties of these 3D gel networks depend strongly on the type and density of cross-links, and these gels can be dried and annealed to form aerogels with both high conductivity (560 S/m) and high surface area (1700 m/g). The results show that both ammonia content and the parent nanosheet morphology (crumpled vs flat) have a strong influence on the cross-linked structure and composition; notably, nitrogen is found in the gels, suggesting that ammonia actively participates in the reaction rather than as a mere catalyst. The GO nanosheet morphology may be altered using spray-drying to obtain crumpled GO (cGO) nanosheets and form cGO gels; this allows for an additional handle in the creation of GO-based gels with tunable density, electrical conductivity, and surface area.
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http://dx.doi.org/10.1021/acs.langmuir.8b00637DOI Listing
July 2018

Whole-transcriptome analysis reveals genetic factors underlying flowering time regulation in rapeseed (Brassica napus L.).

Plant Cell Environ 2018 08 19;41(8):1935-1947. Epub 2018 Jun 19.

Plant Breeding Institute, Christian-Albrechts-University of Kiel, Kiel, Germany.

Rapeseed (Brassica napus L.), one of the most important sources of vegetable oil and protein-rich meals worldwide, is adapted to different geographical regions by modification of flowering time. Rapeseed cultivars have different day length and vernalization requirements, which categorize them into winter, spring, and semiwinter ecotypes. To gain a deeper insight into genetic factors controlling floral transition in B. napus, we performed RNA sequencing (RNA-seq) in the semiwinter doubled haploid line, Ningyou7, at different developmental stages and temperature regimes. The expression profiles of more than 54,000 gene models were compared between different treatments and developmental stages, and the differentially expressed genes were considered as targets for association analysis and genetic mapping to confirm their role in floral transition. Consequently, 36 genes with association to flowering time, seed yield, or both were identified. We found novel indications for neofunctionalization in homologs of known flowering time regulators like VIN3 and FUL. Our study proved the potential of RNA-seq along with association analysis and genetic mapping to identify candidate genes for floral transition in rapeseed. The candidate genes identified in this study could be subjected to genetic modification or targeted mutagenesis and genotype building to breed rapeseed adapted to certain environments.
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http://dx.doi.org/10.1111/pce.13353DOI Listing
August 2018

Surface-agnostic highly stretchable and bendable conductive MXene multilayers.

Sci Adv 2018 03 9;4(3):eaaq0118. Epub 2018 Mar 9.

Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.

Stretchable, bendable, and foldable conductive coatings are crucial for wearable electronics and biometric sensors. These coatings should maintain functionality while simultaneously interfacing with different types of surfaces undergoing mechanical deformation. MXene sheets as conductive two-dimensional nanomaterials are promising for this purpose, but it is still extremely difficult to form surface-agnostic MXene coatings that can withstand extreme mechanical deformation. We report on conductive and conformal MXene multilayer coatings that can undergo large-scale mechanical deformation while maintaining a conductivity as high as 2000 S/m. MXene multilayers are successfully deposited onto flexible polymer sheets, stretchable poly(dimethylsiloxane), nylon fiber, glass, and silicon. The coating shows a recoverable resistance response to bending (up to 2.5-mm bending radius) and stretching (up to 40% tensile strain), which was leveraged for detecting human motion and topographical scanning. We anticipate that this discovery will allow for the implementation of MXene-based coatings onto mechanically deformable objects.
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http://dx.doi.org/10.1126/sciadv.aaq0118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5844711PMC
March 2018

Trophic Transfer and Accumulation of Multiwalled Carbon Nanotubes in the Presence of Copper Ions in Daphnia magna and Fathead Minnow (Pimephales promelas).

Environ Sci Technol 2018 01 5;52(2):794-800. Epub 2018 Jan 5.

Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University , Lubbock, Texas United States.

The increase in use of nanomaterials such as multiwalled carbon nanotubes (MWCNTs) presents a need to study their interactions with the environment. Trophic transfer was measured between Daphnia magna and Pimephales promelas (fathead minnow, FHM) exposed to MWCNTs with different outer diameter (OD) sizes (MWCNT1 = 8-15 nm OD and MWCNT2 = 20-30 nm OD) in the presence and absence of copper. Pristine FHM were fed D. magna, previously exposed for 3 d to MWCNT1 or MWCNT2 (0.1 mg/L) and copper (0.01 mg/L), for 7 d. D. magna bioaccumulated less MWCNT1 (0.02 μg/g) than MWCNT2 (0.06 μg/g), whereas FHM accumulated more MWCNT1 (0.81 μg/g) than MWCNT2 (0.04 μg/g). In the presence of copper, MWCNT bioaccumulation showed an opposite trend. Mostly MWCNT1 (0.03 μg/g) bioaccumulated in D. magna, however less MWCNT1 (0.21 μg/g) than MWCNT2 (0.32 μg/g) bioaccumulated in FHM. Bioaccumulation factors were higher for MWCNT1s than MWCNT2. However, an opposite trend was observed when copper was added. Plasma metallothionein-2 was measured among treatments; however concentrations were not statistically different from the control. This study demonstrates that trophic transfer of MWCNTs is possible in the aquatic environment and further exploration with mixtures can strengthen the understanding of MWCNT environmental behavior.
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http://dx.doi.org/10.1021/acs.est.7b03522DOI Listing
January 2018

Aqueous Exfoliation of Graphite into Graphene Assisted by Sulfonyl Graphene Quantum Dots for Photonic Crystal Applications.

ACS Appl Mater Interfaces 2017 Sep 29;9(36):30797-30804. Epub 2017 Aug 29.

Artie McFerrin Department of Chemical Engineering, Texas A&M University , College Station, Texas 77843, United States.

We investigate the π-π stacking of polyaromatic hydrocarbons (PAHs) with graphene surfaces, showing that such interactions are general across a wide range of PAH sizes and species, including graphene quantum dots. We synthesized a series of graphene quantum dots with sulfonyl, amino, and carboxylic functional groups and employed them to exfoliate and disperse pristine graphene in water. We observed that sulfonyl-functionalized graphene quantum dots were able to stabilize the highest concentration of graphene in comparison to other functional groups; this is consistent with prior findings by pyrene. The graphene nanosheets prepared showed excellent colloidal stability, indicating great potential for applications in electronics, solar cells, and photonic displays which was demonstrated in this work.
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http://dx.doi.org/10.1021/acsami.7b06980DOI Listing
September 2017

Bioaccumulation, stress, and swimming impairment in Daphnia magna exposed to multiwalled carbon nanotubes, graphene, and graphene oxide.

Environ Toxicol Chem 2017 08 6;36(8):2199-2204. Epub 2017 Mar 6.

Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, USA.

The use of carbon-based nanomaterials (CNMs) such as multiwalled carbon nanotubes (MWCNTs), graphene, and graphene oxide (GO) is increasing across many applications because of their unique and versatile properties. These CNMs may enter the aquatic environment through many pathways, creating the potential for organism exposure. The present study addresses the bioaccumulation and toxicity seen in Daphnia magna exposed to CNMs dispersed in sodium dodecyl benzene sulfonate (SDBS). In study I, D. magna were exposed to varying outer diameters of MWCNTs for 24 h in moderately hard or hard freshwater. Bioaccumulation of MWCNT was found in all treatments, with the highest concentrations (0.53 ± 0.27 μg/g) in D. magna exposed in hard freshwater (p < 0.005). The median lethal concentration (LC50) was determined for D. magna exposed to CNMs in moderately hard and hard freshwater. In study II, D. magna were exposed to CNMs for 72 h in moderately hard freshwater to assess swimming velocity and generation of reactive oxygen species (ROS) detected by dichlorofluorescein fluorescence. An overall decrease was seen in D. magna swimming velocity after exposure to CNMs. The generation of ROS was significantly higher (1.54 ± 0.38 dichlorofluorescein mM/mg dry wt) in D. magna exposed to MWCNTs of smaller outer diameters than in controls after 72 h (p < 0.05). These results suggest that further investigation of CNM toxicity and behavior in the aquatic environment is needed. Environ Toxicol Chem 2017;36:2199-2204. © 2017 SETAC.
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http://dx.doi.org/10.1002/etc.3754DOI Listing
August 2017

Graphene reflux: improving the yield of liquid-exfoliated nanosheets through repeated separation techniques.

Nanotechnology 2016 Dec 17;27(50):505601. Epub 2016 Nov 17.

Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA.

Scalable production of graphene through liquid-phase exfoliation has been plagued by low yields. Although several recent studies have attempted to improve graphene exfoliation technology, the problem of separating colloidal nanosheets from unexfoliated parent material has received far less attention. Here we demonstrate a scalable method for improving nanosheet yield through a facile washing process. By probing the sedimentation of liquid-phase exfoliated slurries of graphene nanosheets and parent material, we found that a portion of exfoliated graphene is entrapped in the sediment, but can be recovered by repeatedly washing the slurry of nanosheet and parent material with additional solvent. We found this process to significantly increase the overall yield of graphene (graphene/parent material) and recover a roughly constant proportion of graphene with each wash. The cumulative amount of graphene recovered is only a function of total solvent volume. Moreover, we found this technique to be applicable to other types of nanosheets such as boron nitride nanosheets.
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http://dx.doi.org/10.1088/0957-4484/27/50/505601DOI Listing
December 2016

Challenges in Liquid-Phase Exfoliation, Processing, and Assembly of Pristine Graphene.

Adv Mater 2016 Oct 22;28(40):8796-8818. Epub 2016 Aug 22.

Artie McFerrin Department of Chemical Engineering, College Station, TX, 77843, USA.

Recent developments in the exfoliation, dispersion, and processing of pristine graphene (i.e., non-oxidized graphene) are described. General metrics are outlined that can be used to assess the quality and processability of various "graphene" products, as well as metrics that determine the potential for industrial scale-up. The pristine graphene production process is categorized from a chemical engineering point of view with three key steps: i) pretreatment, ii) exfoliation, and iii) separation. How pristine graphene colloidal stability is distinct from the exfoliation step and is dependent upon graphene interactions with solvents and dispersants are extensively reviewed. Finally, the challenges and opportunities of using pristine graphene as nanofillers in polymer composites, as well as as building blocks for macrostructure assemblies are summarized in the context of large-scale production.
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http://dx.doi.org/10.1002/adma.201601889DOI Listing
October 2016

Determination of uptake, accumulation, and stress effects in corn (Zea mays L.) grown in single-wall carbon nanotube contaminated soil.

Chemosphere 2016 Jun 8;152:117-22. Epub 2016 Mar 8.

Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX, USA. Electronic address:

Single-wall carbon nanotubes (SWNTs) are projected to increase in usage across many industries. Two studies were conducted using Zea L. (corn) seeds exposed to SWNT spiked soil for 40 d. In Study 1, corn was exposed to various SWNT concentrations (0, 10, and 100 mg/kg) with different functionalities (non-functionalized, OH-functionalized, or surfactant stabilized). A microwave induced heating method was used to determine SWNTs accumulated mostly in roots (0-24 μg/g), with minimal accumulation in stems and leaves (2-10 μg/g) with a limit of detection at 0.1 μg/g. Uptake was not functional group dependent. In Study 2, corn was exposed to 10 mg/kg SWNTs (non-functionalized or COOH-functionalized) under optimally grown or water deficit conditions. Plant physiological stress was determined by the measurement of photosynthetic rate throughout Study 2. No significant differences were seen between control and SWNT treatments. Considering the amount of SWNTs accumulated in corn roots, further studies are needed to address the potential for SWNTs to enter root crop species (i.e., carrots), which could present a significant pathway for human dietary exposure.
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http://dx.doi.org/10.1016/j.chemosphere.2016.02.093DOI Listing
June 2016