• Nuclear Engineering and Technology
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• 제50권6호
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• pp.820-828
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• 2018

The growing nuclear threat has amplified the need for developing diverse and accurate nuclear forensics analysis techniques to strengthen nuclear security measures. The work presented here is part of a research effort focused on developing a methodology for reactor-type discrimination of weapons-grade plutonium. To verify the developed methodology, natural $UO_2$ fuel samples were irradiated in a thermal neutron spectrum at the University of Missouri Research Reactor (MURR) and produced approximately $20{\mu}g$ of weapons-grade plutonium test material. Radiation transport simulations of common thermal reactor types that can produce weapons-grade plutonium were performed, and the results are presented here. These simulations were needed to verify whether the plutonium produced in the natural $UO_2$ fuel samples during the experimental irradiation at MURR was a suitable representative to plutonium produced in common thermal reactor types. Also presented are comparisons of fission product and plutonium concentrations obtained from computational simulations of the experimental irradiation at MURR to the nondestructive and destructive measurements of the irradiated natural $UO_2$ fuel samples. Gamma spectroscopy measurements of radioactive fission products were mostly within 10%, mass spectroscopy measurements of the total plutonium mass were within 4%, and mass spectroscopy measurements of stable fission products were mostly within 5%.

• Archives of Plastic Surgery
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• 제48권6호
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• pp.599-606
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• 2021

Background Postoperative dehiscence and surgical site infection after spinal surgery can carry serious morbidity. Multidisciplinary involvement of plastic surgery is essential to minimizing morbidity and achieving definitive closure. However, a standardized approach is lacking. The aim of this study was to identify effective reconstructive interventions for the basis of an evidence-based management protocol. Methods A retrospective review was performed at a single tertiary institution for 45 patients who required 53 reconstruction procedures with plastic surgery for wounds secondary to spinal surgery from 2010 to 2019. Statistical analysis was performed for demographics, comorbidities, and treatment methods. Primary outcomes were postoperative complications, including dehiscence, seroma, and infection. The secondary outcome was time to healing. Results The overall complication rate was 32%, with dehiscence occurring in 17%, seroma in 15% and infection in 11% of cases. Median follow-up was 10 months (interquartile range, 4-23). Use of antibiotic beads did not affect rate of infection occurrence after wound closure (P=0.146). Use of incisional negative pressure wound therapy (iNPWT) was significant for reduced time to healing (P=0.001). Patients treated without iNPWT healed at median of 67.5 days while the patients who received iNPWT healed in 33 days. Demographics and comorbidities between these two groups were similar. Conclusions This data provides groundwork for an evidence-based approach to soft tissue reconstruction and management of dehiscence after spinal surgery. Timely involvement of plastic surgery in high-risk patients and utilization of evidence-based interventions such as iNPWT are essential for improving outcomes in this population.

• Annals of Coloproctology
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• 제34권6호
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• pp.312-316
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• 2018

Purpose: Anemia is associated with poor treatment results for a variety of cancers. The effect of low hemoglobin levels on long-term outcomes after the treatment of patients with an anal squamous cell carcinoma (SCC) remains unclear. For that reason, this study aimed to investigate the effect of anemia on treatment outcomes following chemoradiation for an anal SCC. Methods: This was a retrospective study of all patients who underwent curative treatment for an anal SCC between 2009 and 2015 at 2 trusts in the United Kingdom. Data were collated from prospectively collected cancer databases and were cross-checked with operating-room records and records in the hospitals' patient management systems. Results: We identified 103 patients with a median age of 63 years (range, 36-84 years). The median overall survival was 39 months (range, 9-90 months), and the disease-free survival was 36 months (range, 2-90 months). During the follow-up period, 16.5% patients died and 13.6% patients developed recurrence. Twenty-two people were anemic prior to treatment, with a female preponderance (20 of 22). No differences in disease-free survival (P = 0.74) and overall survival (P = 0.12) were noted between patients with anemia and those with normal hemoglobin levels. On regression the analysis, the combination of anemia, the presence of a defunctioning colostomy, lymph-node involvement and higher tumor stage correlated with poor overall survival. Conclusion: In this study, anemia did not influence disease-free survival or overall survival. We suggest that the interaction between anemia and survival is more complex than previously demonstrated and potentially reliant on other coexisting factors.

• 대한약침학회지
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• 제21권4호
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• pp.284-293
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• 2018

Objectives: Thymoquinone (TQ) is one of the active ingredients of herbal plants such as Nigella sativa L. (NS) which has beneficial effects on the body. The beneficial effects of TQ on the cardiovascular system have reported. This study aimed to investigate the effect of TQ on cardiac fibrosis and permeability, serum and tissue concentration of inflammatory markers and oxidative stress status in chronic lipopolysaccharide exposure in male rats. Methods: Seventy male Wistar rats were randomly divided into five groups as follows: (1) control; (2) LPS (1 mg/kg/day); (3-5) LPS + TQ with three doses of 2, 5 and 10 mg/kg (n=14 in each group). After 3 weeks, serum and cardiac levels of $IL-1{\beta}$, $TNF-{\alpha}$ and nitric oxide (NO) metabolites, and cardiac levels of malondialdehyde (MDA), total thiol groups, catalase (CAT) and superoxide dismutase (SOD) activities, permeability of heart tissue (evaluated by Evans blue dye method) and myocardial fibrosis were determined, histologically. Results: LPS administration induced myocardial and perivascular fibrosis and increased cardiac oxidative stress (MDA), inflammatory markers and heart permeability, while, reduced anti-oxidative enzymes (SOD and CAT) and the total thiol group. Administration of TQ significantly attenuated these observations. Conclusion: TQ improved myocardial and perivascular fibrosis through suppression of chronic inflammation and improving oxidative stress status and can be considered for attenuation of cardiac fibrosis in conditions with chronic low-grade inflammation.

• Archives of Plastic Surgery
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• 제46권4호
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• pp.365-370
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• 2019

The syndrome of the trephined is a neurologic phenomenon that manifests as sudden decline in cognition, behavior, and sensorimotor function due to loss of intracranial domain. This scenario typically occurs in the setting of large craniectomy defects, resulting from trauma, infection, and/or oncologic extirpation. Cranioplasty has been shown to reverse these symptoms by normalizing cerebral hemodynamics and metabolism. However, successful reconstruction may be difficult in patients with complex and/or hostile calvarial defects. We present the case of a 48-year-old male with a large cranial bone defect, who failed autologous cranioplasty secondary to infection, and developed rapid neurologic deterioration leading to a near-vegetative state. Following debridement and antibiotic therapy, delayed cranioplasty was accomplished using a polyetheretherketone (PEEK) implant with free chimeric latissimus dorsi/serratus anterior myocutaneous flap transfer for vascularized resurfacing. Significant improvements in cognition and motor skill were noted in the early postoperative period. At 6-month follow-up, the patient had regained the ability to speak, ambulate and self-feed-correlating with evidence of cerebral/ventricular re-expansion on computed tomography. Based on our findings, we advocate delayed alloplastic implantation with total vascularized soft tissue coverage as a viable alternative for reconstructing extensive, hostile calvarial defects in patients with the syndrome of the trephined.

• Integrative Medicine Research
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• 제6권2호
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• pp.149-155
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• 2017

Background: Naringenin (NRG) is a common dietary polyphenolic constituent of fruits. NRG has diverse pharmacological activities, and is used in traditional medicine to treat various diseases including gastrointestinal (GI) disorders. Interstitial cells of Cajal (ICCs) are pacemaker cells of the GI tract. In this study, the authors investigated the effects of NRG on ICCs and on GI motility in vitro and in vivo. Methods: ICCs were dissociated from mouse small intestines by enzymatic digestion. The whole-cell patch clamp configuration was used to record pacemaker potentials in cultured ICC clusters. The effects of NRG on GI motility were investigated by calculating percent intestinal transit rates (ITR) using Evans blue in normal mice. Results: NRG inhibited ICC pacemaker potentials in a dose-dependent manner. In the presence of tetraethylammonium chloride or iberiotoxin, NRG had no effect on pacemaker potentials, but it continued to block pacemaker potentials in the presence of glibenclamide. Preincubation with SQ-22536 had no effect on pacemaker potentials or on their inhibition by NRG. However, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one blocked pacemaker potential inhibition by NRG. In addition, L-NG-nitroarginine methyl ester blocked pacemaker potential inhibition by NRG. Furthermore, NRG significantly suppressed murine ITR enhancement by neostigmine in vivo. Conclusion: This study shows NRG dose-dependently inhibits ICC pacemaker potentials via a cyclic guanosine monophosphate/nitric oxide-dependent pathway and $Ca^{2+}$-activated $K^+$ channels in vitro. In addition, NRG suppressed neostigmine enhancement of ITR in vivo.

• 천문학회보
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• 제44권1호
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• pp.42.2-42.2
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• 2019

Turbulence is one of the natural phenomena in molecular clouds. It affects gas density and velocity fluctuation within the molecular clouds and controls the mode and tempo of star formation. However, despite many years of study, the properties of turbulence remain poorly understood. As part of the Taeduk Radio Astronomy Observatory (TRAO) Key Science Program (KSP), "mapping Turbulent properties In star-forming MolEcular clouds down to the Sonic scale (TIMES; PI: Jeong-Eun Lee)", we have fully mapped two star-forming molecular clouds, the Orion A and the Ophiuchus molecular clouds, in 3 sets of lines ($^{13}CO$ J=1-0, $C^{18}O$ J=1-0, HCN J=1-0, $HCO^+$ J=1-0, CS J=2-1, and $N_2H^+$ J=1-0) using the TRAO 14-m telescope. We apply a statistical analysis, Principal Component Analysis (PCA), which can recover an underlying turbulent-power spectrum from an observed P-P-V spectral map. We compare turbulence properties not only between the two clouds, but also between different parts within each cloud. We present the first result of our observation program.

• Journal of Chest Surgery
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• 제54권1호
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• pp.9-16
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• 2021

Background: The deposition of monomeric C-reactive protein (mCRP) in the myocardium aggravates ischemia-reperfusion injury (IRI) and myocardial infarction. Ischemic preconditioning (IPC) is known to protect the myocardium against IRI. Methods: We evaluated the effects of IPC on myocardium upon which mCRP had been deposited due to IRI in a rat model. Myocardial IRI was induced via ligation of the coronary artery. Direct IPC was applied prior to IRI using multiple short direct occlusions of the coronary artery. CRP was infused intravenously after IRI. The study included sham (n=3), IRI-only (n=5), IRI+CRP (n=9), and IPC+IRI+CRP (n=6) groups. The infarcted area and the area at risk were assessed using Evans blue and 2,3,5-triphenyltetrazolium staining. Additionally, mCRP immunostaining and interleukin-6 (IL-6) mRNA reverse transcription-polymerase chain reaction were performed. Results: In the IRI+CRP group, the infarcted area and the area of mCRP deposition were greater, and the level of IL-6 mRNA expression was higher, than in the IRI-only group. However, in the IPC+IRI+CRP group relative to the IRI+CRP group, the relative areas of infarction (20% vs. 34%, respectively; p=0.079) and mCRP myocardial deposition (21% vs. 44%, respectively; p=0.026) were lower and IL-6 mRNA expression was higher (fold change: 407 vs. 326, respectively; p=0.376), although the difference in IL-6 mRNA expression was not statistically significant. Conclusion: IPC was associated with significantly decreased deposition of mCRP and with increased expression of IL-6 in myocardium damaged by IRI. The net cardioprotective effect of decreased mCRP deposition and increased IL-6 levels should be clarified in a further study.

• Archives of Plastic Surgery
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• 제48권6호
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• pp.685-690
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• 2021

Background Human immunodeficiency virus (HIV)-associated lipodystrophy is a known consequence of long-term highly active antiretroviral therapy (HAART). However, a significant number of patients on HAART therapy were left with the stigmata of complications, including fat redistribution. Few studies have described the successful removal of focal areas of lipohypertrophy with successful outcomes. This manuscript reviews the outcomes of excisional lipectomy versus liposuction for HIV-associated cervicodorsal lipodystrophy. Methods We performed a 15-year retrospective review of HIV-positive patients with lipodystrophy. Patients were identified by query of secure operative logs. Data collected included demographics, medications, comorbidities, duration of HIV, surgical intervention type, pertinent laboratory values, and the amount of tissue removed. Results Nine male patients with HIV-associated lipodystrophy underwent a total of 17 procedures. Of the patients who underwent liposuction initially (n=5), 60% (n=3) experienced a recurrence. There were a total of three cases of primary liposuction followed by excisional lipectomy. One hundred percent of these cases were noted to have a recurrence postoperatively, and there was one case of seroma formation. Of the subjects who underwent excisional lipectomy (n=4), there were no documented recurrences; however, one patient's postoperative course was complicated by seroma formation. Conclusions HIV-associated lipodystrophy is a disfiguring complication of HAART therapy with significant morbidity. Given the limitations of liposuction alone as the primary intervention, excisional lipectomy is recommended as the primary treatment. Liposuction may be used for better contouring and for subsequent procedures. While there is a slightly higher risk for complications, adjunctive techniques such as quilting sutures and placement of drains may be used in conjunction with excisional lipectomy.

• Archives of Plastic Surgery
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• 제50권3호
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• pp.264-273
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• 2023

The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap, and yet is less commonly utilized than other free flaps in microvascular reconstructions of the head and neck. The aim is to conduct a high-quality Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)- and Assessment of Multiple Systematic Reviews 2 (AMSTAR 2)-compliant systematic review comparing the use of the MSAP flap to other microvascular free flaps in the head and neck. Medline, Embase, and Web of Science databases were searched to identify all original comparative studies comparing patients undergoing head and neck reconstruction with an MSAP flap to the radial forearm free flap (RFFF) or anterolateral thigh (ALT) flap from inception to February 2021. Outcome studied were the recipient-site and donor-site morbidities as well as speech and swallow function. A total of 473 articles were identified from title and abstract review. Four studies met the inclusion criteria. Compared with the RFFF and the ALT flaps, the MSAP flap had more recipient-site complications (6.0 vs 10.4%) but less donor-site complications (20.2 vs 7.8%). The MSAP flap demonstrated better overall donor-site appearance and function than the RFFF and ALT flaps (p = 0.0006) but no statistical difference in speech and swallowing function following reconstruction (p = 0.28). Although higher quality studies reviewing the use of the MSAP flap to other free flaps are needed, the MSAP flap provides a viable and effective reconstructive option and should be strongly considered for reconstruction of head and neck defects.