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1.
Chonnam Med J ; 57(3): 211-218, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34621642

RESUMO

This study was conducted to evaluate the efficacy and safety of once-weekly dulaglutide therapy as add-on to oral antidiabetic drugs (OADs) and basal insulin in Korean patients with type 2 diabetes mellitus (T2DM) in real-world clinical practice. We retrospectively reviewed the medical records of 112 patients who received dulaglutide in a tertiary referral center. The primary efficacy endpoint was a change in glycated hemoglobin (HbA1c) between baseline and 6 months. The secondary endpoints were the percentage of patients achieving HbA1c <7.0% or ≤6.5% and the change of body weight at 6 months. At baseline, the mean HbA1c was 8.7 % (8.8% in the OAD combination and 8.5% in the basal insulin combination group). The mean adjusted HbA1c at 6 months decreased by -1.13% in all patients (p<0.001), and by -1.36 and -0.74% in the OAD combination and basal insulin combination group, respectively. A significant reduction of -2.9 kg in body weight was observed in all patients at 6 months (p<0.001). Approximately 34.8% and 23.2% of patients achieved HbA1c <7.0% and ≤6.5%, respectively. Higher baseline HbA1c and no previous insulin therapy were associated with positive responses to dulaglutide on multivariate analysis. Mild gastrointestinal issues (23.2%) were the most frequently observed adverse events. Dulaglutide is an effective and durable treatment option as OAD and basal insulin combination therapy in Korean patients with T2DM.

2.
Nanomaterials (Basel) ; 11(7)2021 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-34361172

RESUMO

We report an in situ characterization of transition-metal dichalcogenide (TMD) monolayers and twisted bilayers using a high-speed second-harmonic generation (SHG) imaging technique. High-frequency laser modulation and galvano scanning in the SHG imaging enabled a rapid identification of the crystallinity in the TMD, including the orientation and homogeneity with a speed of 1 frame/s. For a twisted bilayer MoS2, we studied the SHG peak intensity and angles as a function of the twist angle under a strong interlayer coupling. In addition, rapid SHG imaging can be used to visualize laser-induced ablation of monolayer and bilayer MoS2 in situ under illumination by a strong femtosecond laser. Importantly, we observed a characteristic threshold behavior; the ablation process occurred for a very short time duration once the preheating condition was reached. We investigated the laser thinning of the bilayer MoS2 with different twist angles. When the twist angle was 0°, the SHG decreased by approximately one-fourth of the initial intensity when one layer was removed. Conversely, when the twist angle was approximately 60° (the SHG intensity was suppressed), the SHG increased abruptly close to that of the nearby monolayer when one layer was removed. Precise layer-by-layer control was possible because of the unique threshold behavior of the laser-induced ablation.

3.
Sci Rep ; 11(1): 16781, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408249

RESUMO

We investigated the variation of current density-voltage (J-V) characteristics of an organic solar cell (OSC) in the dark and at 9 different light intensities ranging from 0.01 to 1 sun of the AM1.5G spectrum. All three conventional parameters, short-circuit currents (Jsc), open-circuit voltage (Voc), and Fill factor (FF), representing OSC performance evolved systematically in response to light intensity increase. Unlike Jsc that showed quasi-linear monotonic increase, Voc and FF showed distinctive non-monotonic variations. To elucidate the origin of such variations, we performed extensive simulation studies including Shockley-Read-Hall (SRH) recombination losses. Simulation results were sensitive to defect densities, and simultaneous agreement to 10 measured J-V curves was possible only with the defect density of [Formula: see text]. Based on analyses of simulation results, we were able to separate current losses into SRH- and bimolecular-recombination components and, moreover, identify that the competition between SRH- and bimolecular-loss currents were responsible for the aforementioned variations in Jsc, Voc, and FF. In particular, we verified that apparent demarcation in Voc, and FF variations, which seemed to appear at different light intensities, originated from the same mechanism of dominance switching between recombination losses.

4.
BMC Endocr Disord ; 21(1): 177, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34461869

RESUMO

BACKGROUND: Thyroid stimulating hormone (TSH) secreting pituitary adenoma (TSHoma) with coexisting thyroid cancer is extremely rare, and proper treatment of both diseases may pose a unique clinical challenge. When TSHoma has plurihormonality, particularly involving the co-secretion of growth hormone (GH), management can be more complicated. Herein, we present a difficult-to-manage case of papillary thyroid cancer with an incurable TSH/GH-secreting pituitary adenoma. CASE PRESENTATION: A 59-year-old man was referred to our hospital due to memory impairment and inappropriate TSH level. Sella magnetic resonance imaging revealed a huge pituitary mass extending to the suprasellar area. Clinical diagnosis of TSH/GH co-secreting pituitary adenoma was made based on elevated free T4, total T3, serum α-subunit, insulin-like growth factor-1 levels and non-suppressible GH levels after oral glucose loading. Rectal cancer and multifocal papillary thyroid microcarcinoma (PTMC) were diagnosed during initial screening for internal malignancy; lower anterior resection was performed and close observation was planned for PTMC. Long-acting octreotide therapy was commenced, which resulted in a dramatic reduction in TSHoma size and facilitated control of hormonal excess. Total thyroidectomy and radioactive iodine (RAI) therapy were needed during follow up due to the growth of PTMC. After the surgery, the pituitary adenoma represented resistance to somatostatin analogue therapy and the tumor size gradually increased despite the addition of dopamine agonist therapy. Furthermore, TSH suppressive therapy with levothyroxine was impossible and an adequate TSH level for RAI therapy was unmountable. Late debulking pituitary surgery was ineffective, and the patient gradually deteriorated and lost to follow up. CONCLUSION: We report the first aggravated case of TSH/GH co-secreting pituitary tumor after total thyroidectomy for concomitant multifocal PTMC. Deferring of thyroid surgery until the TSHoma is well controlled may be the optimal therapeutic strategy in patients with TSHoma and coexistent thyroid cancer; ablative thyroid surgery may result in catastrophic pituitary tumor growth.

5.
PLoS One ; 16(7): e0254630, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34264998

RESUMO

OBJECTIVES: Low-normal thyroid function is associated with numerous metabolic risk factors including insulin resistance (IR). Triglyceride-glucose (TyG) index is a new surrogate marker of IR calculated by fasting triglyceride and glucose levels. Here, we investigated the association between thyroid function and TyG index in non-diabetic euthyroid adults. METHODS: This cross-sectional study was based on data from the Korean National Health and Nutritional Examination Survey 2015 including 1482 individuals (741 men and 741 women). Serum thyrotropin (TSH) and free thyroxine (fT4) levels were measured. RESULTS: After adjusting for confounders, there was an inverse relationship of TyG index with fT4 in men (ß = -0.094, P = 0.009) and a positive relationship of TyG index with TSH in women (ß = 0.078, P = 0.018). The lowest fT4 tertile in men (P = 0.001) and the highest TSH tertile in women (P = 0.010) exhibited increased TyG index after adjusting for confounders. The lowest fT4 tertile also showed increased homeostatic model assessment for IR (HOMA-IR) only in men (P = 0.006). Odds ratios (ORs) for the high TyG index, which was defined as the highest TyG quartile decreased in the highest and second highest tertile of fT4 in men (OR = 0.41 and OR = 0.45, respectively; P < 0.001) and increased in highest tertile of TSH in women (OR = 1.81, P = 0.031) after adjusting for confounders. The OR for high HOMA-IR defined as the highest HOMA-IR quartile was also lower in the highest and second highest fT4 tertiles in men (both OR = 0.47; P = 0.003). CONCLUSIONS: This is the first study to suggest that TyG index is a good surrogate marker of IR in evaluating its relationship with thyroid function.


Assuntos
Resistência à Insulina , Inquéritos Nutricionais , Triglicerídeos , Adulto , Estudos Transversais , Feminino , Glucose , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia , Glândula Tireoide
6.
Pituitary ; 24(6): 955-963, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34189717

RESUMO

PURPOSE: Dopamine agonists (DAs) have long been the recommended first-line treatment for prolactinoma. Given the remarkable developments in surgical techniques, however, surgery is on the rise. We compared the treatment outcomes of patients with noninvasive prolactinomas receiving two different initial treatments (DAs and transsphenoidal surgery). METHODS: We reviewed 745 patients with hyperprolactinemia or pituitary tumors treated from 2004 to 2020 at Chonnam National University Hwasun Hospital and identified 310 with prolactinomas. After selecting patients who had pituitary tumors with Knosp grade 0 to 1 with follow-up period over 1 year, 70 patients (29 who underwent surgery and 41 who received DAs as the initial treatment) were finally included for a comparative study. RESULTS: The surgery group exhibited better outcomes in terms of DA-free remission and the structural response, although the tumor size was significantly larger than in the DA group. The groups exhibited comparable results in terms of symptom control and the biochemical response. Univariate and multivariate analyses indicated that surgery as the initial treatment modality provided significantly better clinical outcomes in terms of DA-free remission. In the surgery group, a postoperative prolactin level < 10 ng/mL was the only significant predictor of DA-free remission. CONCLUSIONS: Transsphenoidal surgery showed comparable clinical outcomes in patients with prolactinomas, and low complication rates. The decision regarding the first-line treatment modality for non-invasive prolactinomas should be made on an individual basis.

7.
Endocrinol Metab (Seoul) ; 36(3): 599-606, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34074094

RESUMO

BACKGROUND: Programmed cell death-ligand 1 (PD-L1) has an important role in regulating immune reactions by binding to programmed death 1 (PD-1) on immune cells, which could prevent the exacerbation of autoimmune thyroid disease (AITD). The aim of this study was to evaluate the association of PD-L1 polymorphism with AITD, including Graves' disease (GD) and Hashimoto's thyroiditis (HT). METHODS: A total of 189 GD patients, 234 HT patients, and 846 healthy age- and sex-matched controls were enrolled in this study. We analyzed PD-L1 single nucleotide polymorphism (SNP) (rs822339) and investigated the associations with clinical disease course and outcome. RESULTS: Genotype frequency at the PD-L1 marker RS822339 in GD (P=0.219) and HT (P=0.764) patients did not differ from that among healthy controls. In patients with GD, the A/G or G/G genotype group demonstrated higher TBII titer (20.6±20.5 vs. 28.0± 25.8, P=0.044) and longer treatment duration (39.0±40.4 months vs. 62.4±65.0 months, P=0.003) compared to the A/A genotype group. Among patients in whom anti-thyroid peroxidase (TPO) antibody was measured after treatment of GD, post-treatment antiTPO positivity was higher in the A/G or G/G genotype group compared to the A/A genotype group (48.1% vs. 69.9%, P=0.045). Among patients with HT, there was no significant difference of anti-TPO antibody positivity (79.4% vs. 68.6%, P=0.121), anti-thyroglobulin antibody positivity (80.9% vs. 84.7%, P=0.661), or development to overt hypothyroidism (68.0% vs. 71.1%, P=0.632) between the A/A genotype group and the A/G or G/G genotype group. CONCLUSION: The genotype frequency of PD-L1 (rs822339) is not different in patients with AITD compared with healthy controls. The intact PD-1/PD-L1 pathway in GD and HT might be important to maintain chronicity of AITD by protecting immune tolerance. However, the PD-L1 SNP could be associated with difficulty in achieving remission in patients with GD, which may be helpful to predict the possibility of longer treatment. Further studies are required to investigate the complex immune tolerance system in patients with AITD.

8.
Mol Imaging Biol ; 23(5): 703-713, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33768465

RESUMO

PURPOSE: In this study, a small animal PET insert (SimPET-X, Brightonix Imaging Inc.) for simultaneous PET/MR imaging studies is presented. This insert covers an 11-cm-long axial field-of-view (FOV) and enables imaging of mouse total-bodies and rat heads. PROCEDURES: SimPET-X comprises 16 detector modules to yield a ring diameter of 63 mm and an axial FOV of 110 mm. The detector module supports four detector blocks, each comprising two 4 × 4 SiPM arrays coupled with a 20 × 9 array of LSO crystals (1.2 × 1.2 × 10 mm3). The physical characteristics of SimPET-X were measured in accordance with the NEMA NU4-2008 standard protocol. In addition, we assessed the compatibility of SimPET-X with a small animal-dedicated MRI (M7, Aspect Imaging) and conducted phantom and animal studies. RESULTS: The radial spatial resolutions at the center based on 3D OSEM without and with the warm background were 0.73 mm and 0.99 mm, respectively. The absolute peak sensitivity of the system was 10.44% with an energy window of 100-900 keV and 8.27% with an energy window of 250-750 keV. The peak NECR and scatter fraction for the mouse phantom were 348 kcps at 26.2 MBq and 22.1% with an energy window of 250-750 keV, respectively. The standard deviation of pixel value in the uniform region of an NEMA IQ phantom was 4.57%. The spillover ratios for air- and water-filled chambers were 9.0% and 11.0%, respectively. In the hot-rod phantom image reconstructed using 3D OSEM-PSF, all small rods were resolved owing to the high spatial resolution of the SimPET-X system. There was no notable interference between SimPET-X and M7 MRI. SimPET-X provided high-quality mouse images with superior spatial resolution, sensitivity, and counting rate performance. CONCLUSION: SimPET-X yielded a remarkably improved sensitivity and NECR compared with SimPETTM.

9.
ACS Appl Mater Interfaces ; 13(10): 12241-12249, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33683094

RESUMO

Self-powered ultraviolet photodetectors offer great potential in the field of optical communication, smart security, space exploration, and others; however, achieving high sensitivity with maintaining fast response speed has remained a daunting challenge. Here, we develop a titanium dioxide-based self-powered ultraviolet photodetector with high detectivity (≈1.8 × 1010 jones) and a good photoresponsivity of 0.32 mA W-1 under pulsed illumination (λ = 365 nm, 4 mW cm-2), which demonstrate an enhancement of 114 and 2017%, respectively, due to the alternating current photovoltaic effect compared to the conventional direct current photovoltaic effect. Further, the photodetector demonstrated a high on/off ratio (≈103), an ultrafast rise/decay time of 112/63 µs, and a noise equivalent power of 5.01 × 10-11 W/Hz1/2 under self-biased conditions. Photoconductive atomic force microscopy revealed the nanoscale charge transport and offered the possibility to scale down the device size to a sub-10-nanometer (∼35 nm). Moreover, as one of the practical applications, the device was successfully utilized to interpret the digital codes. The presented results enlighten a new path to design energy-efficient ultrafast photodetectors not only for the application of optical communication but also for other advanced optoelectronic applications such as digital display, sensing, and others.

10.
Korean J Radiol ; 22(4): 624-633, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33569929

RESUMO

OBJECTIVE: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. MATERIALS AND METHODS: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. RESULTS: The skeletal muscle area (threshold, ?29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. CONCLUSION: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.


Assuntos
Músculo Esquelético/diagnóstico por imagem , Imagens de Fantasmas , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Humanos , Doses de Radiação , Sarcopenia/diagnóstico , Sarcopenia/diagnóstico por imagem , Razão Sinal-Ruído , Tomografia Computadorizada por Raios X/instrumentação
11.
Nanoscale ; 13(7): 4262-4268, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33595024

RESUMO

Two-dimensional transition metal dichalcogenides (TMDCs) integrated into photonic structures provide an intriguing playground for the development of novel optoelectronic devices with improved performance. Here, we show the enhanced light emission from TMDC based van der Waals heterostructures through coupling with microsphere cavities. We observe cavity-induced emission enhancement of TMDC materials which varies by an order of magnitude, depending on the size of the microsphere and thickness of the supporting oxide substrate. Furthermore, we demonstrate microsphere cavity-enhanced electroluminescence of a van der Waals light emitting transistor, showing the potential of 2D material based hybrid optoelectronic structures.

12.
Gut ; 70(12): 2249-2260, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33558271

RESUMO

OBJECTIVE: Dysfunctional resolution of intestinal inflammation and altered mucosal healing are essential features in the pathogenesis of inflammatory bowel disease (IBD). Intestinal macrophages are vital in the process of inflammation resolution, but the mechanisms underlying their mucosal healing capacity remain elusive. DESIGN: We investigated the role of the prostaglandin E2 (PGE2) receptor PTGER4 on the differentiation of intestinal macrophages in patients with IBD and mouse models of intestinal inflammation. We studied mucosal healing and intestinal epithelial barrier regeneration in Csf1r-iCre Ptger4fl/fl mice during dextran sulfate sodium (DSS)-induced colitis. The effect of PTGER4+ macrophage secreted molecules was investigated on epithelial organoid differentiation. RESULTS: Here, we describe a subset of PTGER4-expressing intestinal macrophages with mucosal healing properties both in humans and mice. Csf1r-iCre Ptger4fl/fl mice showed defective mucosal healing and epithelial barrier regeneration in a model of DSS colitis. Mechanistically, an increased mucosal level of PGE2 triggers chemokine (C-X-C motif) ligand 1 (CXCL1) secretion in monocyte-derived PTGER4+ macrophages via mitogen-activated protein kinases (MAPKs). CXCL1 drives epithelial cell differentiation and proliferation from regenerating crypts during colitis. Specific therapeutic targeting of macrophages with liposomes loaded with an MAPK agonist augmented the production of CXCL1 in vivo in conditional macrophage PTGER4-deficient mice, restoring their defective epithelial regeneration and favouring mucosal healing. CONCLUSION: PTGER4+ intestinal macrophages are essential for supporting the intestinal stem cell niche and regeneration of the injured epithelium. Our results pave the way for the development of a new class of therapeutic targets to promote macrophage healing functions and favour remission in patients with IBD.

13.
Light Sci Appl ; 10(1): 19, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33479204

RESUMO

Twisted bilayer graphene (tBLG) has received substantial attention in various research fields due to its unconventional physical properties originating from Moiré superlattices. The electronic band structure in tBLG modified by interlayer interactions enables the emergence of low-energy van Hove singularities in the density of states, allowing the observation of intriguing features such as increased optical conductivity and photocurrent at visible or near-infrared wavelengths. Here, we show that the third-order optical nonlinearity can be considerably modified depending on the stacking angle in tBLG. The third-harmonic generation (THG) efficiency is found to significantly increase when the energy gap at the van Hove singularity matches the three-photon resonance of incident light. Further study on electrically tuneable optical nonlinearity reveals that the gate-controlled THG enhancement varies with the twist angle in tBLG, resulting in a THG enhanced up to 60 times compared to neutral monolayer graphene. Our results prove that the twist angle opens up a new way to control and increase the optical nonlinearity of tBLG, suggesting rotation-induced tuneable nonlinear optics in stacked two-dimensional material systems.

14.
Calcif Tissue Int ; 108(2): 176-187, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33006085

RESUMO

The association of insulin resistance (IR), as indicated by the homeostasis model assessment of insulin resistance, with bone metabolism is yet to be clarified. We aimed to investigate the relationship of IR with bone mass by using the triglyceride-glucose (TyG) index as an alternative marker of IR. Data of 4810 non-diabetes individuals (2552 men aged ≥ 50 years and 2258 postmenopausal women) from the Korean National Health and Nutritional Examination Survey IV and V were analyzed. Bone mineral density (BMD) at the lumbar spine, femoral neck, total hip, and whole body were measured using dual-energy X-ray absorptiometry. After adjusting for confounding factors, there were inverse relationships of TyG index with femoral neck, total hip, and whole body BMD in men (ß = - 0.085, P < 0.001 at femoral neck; ß = - 0.046, P = 0.037 at total hip; ß = - 0.098, P < 0.001 at whole body). However, in women, femoral neck and whole body BMD were negatively associated with the TyG index (ß = - 0.071, P = 0.008 at femoral neck and ß = - 0.065, P = 0.005 at whole body). The highest TyG index tertile exhibited reduced femoral neck BMD in both sexes (P = 0.003 in men and P = 0.013 in women) and reduced whole body BMD in men (P < 0.001) after adjusting for confounders. When the study subjects were divided into BMI (body mass index) < 23 kg/m2 and ≥ 23 kg/m2 groups, the TyG index was significantly associated with femoral neck BMD only in the women with BMI < 23 kg/m2 (P = 0.009). We observed a significant association between the highest TyG index tertile and low bone mass at the femoral neck in women with BMI < 23 kg/m2 (P = 0.003) that was not observed in women with BMI ≥ 23 kg/m2 and men. In conclusion, IR evaluated using the TyG index was inversely associated with femoral neck BMD in non-diabetic men aged ≥ 50 years and postmenopausal women. The negative influence of IR on femoral neck BMD was robust in the women with BMI < 23 kg/m2. This indicates a differential effect of IR on BMD according to skeletal site, sex, and BMI.


Assuntos
Glicemia , Densidade Óssea , Triglicerídeos/sangue , Absorciometria de Fóton , Índice de Massa Corporal , Diabetes Mellitus , Feminino , Colo do Fêmur , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , República da Coreia
15.
Molecules ; 26(1)2020 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-33379310

RESUMO

Hydrogen sulfide (H2S) is the third gasotransmitter and is generated endogenously in hypoxic or inflammatory tissues and various cancers. We have recently demonstrated that endogenous H2S can be imaged with [99mTc]Tc-gluconate. In the present study, we detected H2S generated in hypoxic tissue, both in vitro and in vivo, using [99mTc]Tc-gluconate. In vitro uptake of [99mTc]Tc-gluconate was measured under hypoxic and normoxic conditions, using the colon carcinoma cell line CT26, and was higher in hypoxic cells than that in normoxic cells. An acute hindlimb ischemia-reperfusion model was established in BALB/c mice by exposing the animals to 3 h of ischemia and 3 h of reperfusion prior to in vivo imaging. [99mTc]Tc-gluconate (12.5 MBq) was intravenously injected through the tail vein, and uptake in the lower limb was analyzed by single-photon emission computed tomography/computed tomography (SPECT/CT). SPECT/CT images showed five times higher uptake in the ischemic limb than that in the normal limb. The standard uptake value (SUVmean) of the ischemic limb was 0.39 ± 0.03, while that of the normal limb was 0.07 ± 0.01. [99mTc]Tc-gluconate is a novel imaging agent that can be used both in vitro and in vivo for the detection of endogenous H2S generated in hypoxic tissue.


Assuntos
Gluconatos/metabolismo , Sulfeto de Hidrogênio/metabolismo , Hipóxia/metabolismo , Compostos de Organotecnécio/metabolismo , Compostos Radiofarmacêuticos/metabolismo , Tecnécio/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Membro Posterior/metabolismo , Isquemia/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Traumatismo por Reperfusão/metabolismo , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único/métodos
16.
Ann Surg Treat Res ; 99(3): 131-137, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32908844

RESUMO

Purpose: Necrotizing fasciitis (NF) is one of the most severe healthcare-associated infections. Early diagnosis of NF is difficult because of nonspecific signs and symptoms in the early stage. NF often presents with risks of medicolegal disputes. This study aimed to provide baseline data on the general characteristics of medical accidents involving NF, features of NF, and typical court opinions regarding medical malpractice in Korea. Methods: In this study, 25 cases of medical malpractice litigation involving NF sentenced between 1998 and 2018 were analyzed with respect to 3 variables: medical accident, NF, and breach of duty. Results: The department of colorectal surgery was most frequently involved in litigation cases (40.0%), and colorectal surgery was the most frequent procedure before the diagnosis of NF (40.0%). The most common sites were the upper and lower extremities. The courts agreed that there was typically improper monitoring after treatment, frequently related to NF. Conclusion: These litigation cases imply that physicians cannot be blamed for the failure to prevent NF. The timely recognition and management of NF might be considered as one of the main factors for deciding malpractice in court. Therefore, surgeons, especially in the department of colorectal surgery, should pay attention to changes in the patient's status after surgery. Surgeons need to learn from medical accidents, as it is important for risk management, preventing the occurrence of similar cases, and improving the quality of healthcare services. We report the medicolegal implications from medical lawsuits involving NF.

17.
Nano Lett ; 20(9): 6690-6696, 2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32786930

RESUMO

In this work, we demonstrated a phonon-polariton in the terahertz (THz) frequency range, generated in a crystallized lead halide perovskite film coated on metamaterials. When the metamaterial resonance was in tune with the phonon resonance of the perovskite film, Rabi splitting occurred due to the strong coupling between the resonances. The Rabi splitting energy was about 1.1 meV, which is larger than the metamaterial and phonon resonance line widths; the interaction potential estimation confirmed that the strong coupling regime was reached successfully. We were able to tune the polaritonic branches by varying the metamaterial resonance, thereby obtaining the dispersion curve with a clear anticrossing behavior. Additionally, we performed in situ THz spectroscopy as we annealed the perovskite film and studied the Rabi splitting as a function of the films' crystallization coverage. The Rabi splitting versus crystallization volume fraction exhibited a unique power-law scaling, depending on the crystal growth dimensions.

18.
Am J Transl Res ; 12(6): 2488-2498, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32655786

RESUMO

Human serum albumin (HSA) accumulates in tumors by the enhanced permeability and retention (EPR) effect, which is a passive targeting effect in tumors. A recent study showed that secreted protein acidic and rich in cysteine (SPARC), an albumin-binding protein, mediates albumin accumulation in tumors. Arg-Gly-Asp (RGD) is a peptide targeting integrin αvß3, which is highly expressed during tumor angiogenesis. We investigated whether conjugation of RGD to HSA could synergistically enhance tumor targeting. Accumulation of cRGDyK-HSA in integrin αvß3-expressing SK-OV3 cells was observed by confocal microscopy. In SK-OV3 cells overexpressing the albumin binding protein SPARC, cellular uptake of HSA increased, but uptake of cRGDyK-HSA did not. cRGDyK-HSA showed decreased tumor accumulation compared with HSA by positron emission tomography (PET) scanning and biodistribution studies in an SK-OV3 xenograft mouse model. In SK-OV3 tumors, HSA accumulation colocalized with SPARC expression, while cRGDyK-HSA only accumulated in the outer region of the tumor, even though SPARC and integrin αvß3 were expressed within the tumor core. We speculate that cRGDyK conjugation to HSA changes the characteristics of HSA and hinders its tumor-targeting effect. Therefore, HSA should be modified to preserve its native characteristics and enhance the tumor-targeting effects of HSA conjugates.

19.
Mol Imaging Biol ; 22(5): 1208-1217, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32285357

RESUMO

PURPOSE: SimPET/M7 system is a small-animal dedicated simultaneous positron emission tomography and magnetic resonance imaging (PET/MRI) scanner. The SimPET insert has been upgraded from its prototype with a focus on count rate performance and sensitivity. The M7 scanner is a 1-T permanent magnet-based compact MRI system without any cryogens. Here, we present performance evaluation results of SimPET along with the results of mutual interference evaluation and simultaneously acquired PET/MR imaging. PROCEDURES: Following NEMA NU 4-2008 standard, we evaluated the performance of the SimPET system. The M7 MRI compatibility of SimPET was also assessed by analyzing MRI images of a uniform phantom under different PET conditions and PET count rates with different MRI pulse sequences. Mouse imaging was performed including a whole-body 18F-NaF PET scan and a simultaneous PET/MRI scan with 64Cu-NOTA-ironoxide. RESULTS: The spatial resolution at center based on 3D OSEM without and with warm background was 0.7 mm and 1.45 mm, respectively. Peak sensitivity was 4.21 % (energy window = 250-750 keV). The peak noise equivalent count rate with the same energy window was 151 kcps at 38.4 MBq. The uniformity was 4.42 %, and the spillover ratios in water- and air-filled chambers were 14.6 % and 12.7 %, respectively. In the hot rod phantom image, 0.75-mm-diameter rods were distinguishable. There were no remarkable differences in the SNR and uniformity of MRI images and PET count rates with different PET conditions and MRI pulse sequences. In the whole-body 18F-NaF PET images, fine skeletal structures were well resolved. In the simultaneous PET/MRI study with 64Cu-NOTA-ironoxide, both PET and MRI signals changed before and after injection of the dual-modal imaging probe, which was evident with the exact spatiotemporal correlation. CONCLUSIONS: We demonstrated that the SimPET scanner has a high count rate performance and excellent spatial resolution. The combined SimPET/M7 enabled simultaneous PET/MR imaging studies with no remarkable mutual interference between the two imaging modalities.


Assuntos
Imageamento por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Algoritmos , Animais , Imageamento Tridimensional , Masculino , Camundongos Endogâmicos C57BL , Imagens de Fantasmas
20.
Sci Rep ; 10(1): 4317, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32132551

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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