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OBJECTIVES: To use clinical, radiographic, and CT radiomics features to develop and validate a preoperative prediction model for the early recurrence of pancreatic cancer. METHODS: We retrospectively analyzed 190 patients (150 and 40 in the development and test cohort from different centers) with pancreatic cancer who underwent pancreatectomy between January 2018 and June 2021. Radiomics, clinical-radiologic (CR), and clinical-radiologic-radiomics (CRR) models were developed for the prediction of recurrence within 12 months after surgery. Performance was evaluated using the area under the curve (AUC), Brier score, sensitivity, and specificity. RESULTS: Early recurrence occurred in 36.7% and 42.5% of the development and test cohorts, respectively (P = 0.62). The features for the CR model included carbohydrate antigen 19-9 > 500 U/mL (odds ratio [OR], 3.60; P = 0.01), abutment to the portal and/or superior mesenteric vein (OR, 2.54; P = 0.054), and adjacent organ invasion (OR, 2.91; P = 0.03). The CRR model demonstrated significantly higher AUCs than the radiomics model in the internal (0.77 vs. 0.73; P = 0.048) and external (0.83 vs. 0.69; P = 0.038) validations. Although we found no significant difference between AUCs of the CR and CRR models (0.83 vs. 0.76; P = 0.17), CRR models showed more balanced sensitivity and specificity (0.65 and 0.87) than CR model (0.41 and 0.91) in the test cohort. CONCLUSIONS: The CRR model outperformed the radiomics and CR models in predicting the early recurrence of pancreatic cancer, providing valuable information for risk stratification and treatment guidance.
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Neoplasias Pancreáticas , Radiómica , Humanos , Estudios Retrospectivos , Neoplasias Pancreáticas/diagnóstico por imagen , Neoplasias Pancreáticas/cirugía , Área Bajo la Curva , Tomografía Computarizada por Rayos XRESUMEN
Recently, metal halide perovskite-based top cells have shown significant potential for use in inexpensive and high-performance tandem solar cells. In state-of-the-art p-i-n perovskite/Si tandem devices, atomic-layer-deposited SnO2 has been widely used as a buffer layer in the top cells because it enables conformal, pinhole-free, and highly transparent buffer layer formation. In this work, the effects of various electrical properties of SnO2 and C60 layers on the carrier transport characteristics and the performance of the final devices were investigated using a numerical simulation method, which was established based on real experimental data to increase the validity of the model. It was found that the band alignment at the SnO2/C60 interface does, indeed, have a significant impact on the electron transport. In addition, as a general design rule, it was suggested that at first, the conduction band offset (CBO) between C60 and SnO2 should be chosen so as not to be too negative. However, even in a case in which this CBO condition is not met, we would still have the means to improve the electron transport characteristics by increasing the doping density of at least one of the two layers of C60 and/or SnO2, which would enhance the built-in potential across the perovskite layer and the electron extraction at the C60/SnO2 interface.
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Malnutrition might play a key role in the prognosis of patients with Crohn's disease (CD). The aim of this study was to explore the impact of weight loss from diagnosis of CD to one-year post-diagnosis on disease prognosis in terms of surgery. Patients who were diagnosed with CD at Samsung Medical Center between 1995 to 2020 were included in this study. The study defined the "group with weight loss" as patients with weight loss in one year after diagnosis and the "group without body weight loss" as patients without weight loss in one year after diagnosis. Their data such as demographics, laboratory findings, and medical interventions were collected retrospectively. The primary outcome was confirmation of the difference in the incidence of surgery associated with CD between the group with weight loss and the group without body weight loss. We further analyzed factors associated with surgery outcomes. A total of 165 patients were analyzed in this study. Forty-one patients (24.8%) had body weight loss whereas 124 patients (75.2%) had no body weight loss. Body change at one year showed no significant association with direct surgical incidence. However, the patients with weight loss tended to undergo surgery earlier than patients without body weight loss. Among factors associated with outcomes of Crohn's surgery, the albumin was the only significant factor. Patients with weight loss had no statistically significant increase in the risk of surgery than patients without weight loss, although they tended to undergo surgery earlier than patients without body weight loss. A prospective study is needed to determine serial body weight changes during follow-up for patients with CD.
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Enfermedad de Crohn , Humanos , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/cirugía , Enfermedad de Crohn/complicaciones , Estudios Retrospectivos , Pérdida de Peso , Pronóstico , Estudios ProspectivosRESUMEN
Bacterial leaf blight of carrots caused by Xanthomonas hortorum pv. carotae (Xhc) is an important worldwide seed-borne disease. In 2012 and 2013, symptoms similar to bacterial leaf blight were found in carrot farms in Jeju Island, Korea. The phenotypic characteristics of the Korean isolation strains were similar to the type strain of Xhc. Pathogenicity showed symptoms on the 14th day after inoculation on carrot plants. Identification by genetic method was multi-position sequencing of the isolated strain JJ2001 was performed using four genes (danK, gyrB, fyuA, and rpoD). The isolated strain was confirmed to be most similar to Xhc M081. Furthermore, in order to analyze the genetic characteristics of the isolated strain, whole genome analysis was performed through the next-generation sequencing method. The draft genome size of JJ2001 is 5,443,372 bp, which contains 63.57% of G + C and has 4,547 open reading frames. Specifically, the classification of pathovar can be confirmed to be similar to that of the host lineage. Plant pathogenic factors and determinants of the majority of the secretion system are conserved in strain JJ2001. This genetic information enables detailed comparative analysis in the pathovar stage of pathogenic bacteria. Furthermore, these findings provide basic data for the distribution and diagnosis of Xanthomonas hortorum pv. carotae, a major plant pathogen that infects carrots in Korea.
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Fine control of structural and morphological features in electrochromic materials is of paramount importance for realizing practical electrochromic devices (ECDs), which can dynamically adjust indoor light and temperature of buildings. To this end, herein we investigate impacts of two variants such as Ti-doping amount and the annealing temperature on physical and chemical properties of sol-gel derived electrochromic WO3 films. We use a wide range of titanium coupling agents (TCAs) as Ti-dopants ranging from 0 wt% to 20 wt% and vary the annealing temperature between 200 °C and 400 °C with 50 °C interval. Both variants greatly influence the physical properties of the resulting WO3 films, resulting in different crystallinities and morphologies. Through complementary analytical techniques, we find that the WO3 film featuring an amorphous phase with nano-porous morphology enhances the electrochemical and electrochromic performances. The specific TCA used in this study helps stabilize the amorphous WO3 structure and generate the nano-pores during the following thermal treatment via its thermal decomposition. As a result, the WO3 film having an optimal 8 wt% TCA annealed at 300 °C shows a high optical density of 73.78% in visible light (400-780 nm), rapid switching speed (t c = 5.12 s and t b = 4.74 s), and high coloration efficiency of 52.58 cm2 C-1 along with a superior cyclic stability. Thus, understanding a structure-property relationship is of paramount importance in engineering the advanced electrochromic WO3 for use in practical ECDs and other optoelectronic applications.
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OBJECTIVES: The outlook of artificial intelligence for healthcare (AI4H) is promising. However, no studies have yet discussed the issues from the perspective of stakeholders in Korea. This research aimed to identify stakeholders' requirements for AI4H to accelerate the business and research of AI4H. METHODS: We identified research funding trends from the Korean National Science and Technology Knowledge Information Service (NTIS) from 2015 and 2019 using "healthcare AI" and related keywords. Furthermore, we conducted an online survey with members of the Korean Society of Artificial Intelligence in Medicine to identify experts' opinions regarding the development of AI4H. Finally, expert interviews were conducted with 13 experts in three areas (hospitals, industry, and academia). RESULTS: We found 160 related projects from the NTIS. The major data type was radiology images (59.4%). Dermatology-related diseases received the most funding, followed by pulmonary diseases. Based on the survey responses, radiology images (23.9%) were the most demanding data type. Over half of the solutions were related to diagnosis (33.3%) or prognosis prediction (31%). In the expert interviews, all experts mentioned healthcare data for AI solutions as a major issue. Experts in the industrial field mainly mentioned regulations, practical efficacy evaluation, and data accessibility. CONCLUSIONS: We identified technology, regulatory, and data issues for practical AI4H applications from the perspectives of stakeholders in hospitals, industry, and academia in Korea. We found issues and requirements, including regulations, data utilization, reimbursement, and human resource development, that should be addressed to promote further research in AI4H.
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We investigated the clinical relevance of urinary cytokines/chemokines reflecting intrarenal immunologic micromilieu as prognostic markers and the optimal measurement timing after living donor kidney transplantation (LDKT). This prospective cohort study included 77 LDKT patients who were followed for ≥ 5 years. Patients were divided into control (n = 42) or acute rejection (AR, n = 35) group. Early AR was defined as AR occurring within 3 months. Serum and urine cytokines/chemokines were measured serially as follows: intraoperative, 8/24/72 h, 1 week, 3 months, and 1 year after LDKT. Intrarenal total leukocytes, T cells, and B cells were analyzed with immunohistochemistry followed by tissueFAXS. Urinary MCP-1 and fractalkine were also analyzed in a validation cohort. Urinary MCP-1 after one week was higher in the AR group. Urinary MCP-1, fractalkine, TNF-α, RANTES, and IL-6 after one week were significantly higher in the early AR group. Intrarenal total leukocytes and T cells were elevated in the AR group compared with the control group. Urinary fractalkine, MCP-1, and IL-10 showed positive correlation with intrarenal leukocyte infiltration. Post-KT 1 week urinary MCP-1 showed predictive value in the validation cohort. One-week post-KT urinary MCP-1 may be used as a noninvasive diagnostic marker for predicting AR after LDKT.
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Quimiocina CCL2/orina , Rechazo de Injerto/diagnóstico , Trasplante de Riñón/efectos adversos , Adulto , Biomarcadores/orina , Quimiocinas/sangre , Citocinas/sangre , Femenino , Tasa de Filtración Glomerular , Rechazo de Injerto/orina , Humanos , Masculino , Valor Predictivo de las Pruebas , Estudios ProspectivosRESUMEN
Morphine is widely used in pain management although the risk of side effects is significant. The use of biased agonists to the G protein of µ-opioid receptors has been suggested as a potential solution, although oliceridine and PZM21 have previously failed to demonstrate benefits in clinical studies. An amplification-induced confusion in the process of comparing G protein and beta-arrestin pathways may account for previously biased agonist misidentification. Here, we have devised a strategy to discover biased agonists with intrinsic efficacy. We computationally simulated 430â¯000 molecular dockings to the µ-opioid receptor to construct a compound library. Hits were then verified experimentally. Using the verified compounds, we performed simulations to build a second library with a common scaffold and selected compounds that showed a bias to µ- and δ-opioid receptors in a cell-based assay. Three compounds (ID110460001, ID110460002, and ID110460003) with a dual-biased agonistic effect for µ- and δ-opioid receptors were identified. These candidates are full agonists for the µ-opioid receptor and show specific binding modes. On the basis of our findings, we expect our novel compounds to act as more biased agonists compared to existing drugs, including oliceridine.
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BACKGROUND: The prognostic or predictive value of commonly used multigene assays in young patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) early breast cancer is unclear. In this study, we assessed the prognostic value of the GenesWell BCT assay according to age group. METHODS: We identified patients with pN0-1, HR+/HER2- breast cancer in a prospective cohort of women who underwent surgery between 2005 and 2017. The GenesWell BCT assay was performed on tissue samples from selected patients. Distant metastasis-free survival (DMFS) and disease-free survival (DFS) were compared between the risk groups assigned by the BCT score. RESULTS: A total of 712 patients were eligible for analysis. The median follow-up time was 7.47 years. The BCT score was prognostic in patients aged ≤50 years (n = 404) and those aged >50 years (n = 308). In both age groups, the 10-year DMFS and DFS rates for patients classified as high risk by the BCT score were significantly lower than those for patients classified as low risk. A multivariate analysis revealed that the BCT score was an independent prognostic factor for DFS in patients aged ≤50 years (hazard ratio, 1.28; 95% CI, 1.05-1.56; P = 0.015), as well as those aged >50 years. CONCLUSION: The BCT score could be used to identify low-risk patients who will not benefit from adjuvant chemotherapy to treat HR+/HER2- early breast cancer regardless of age. A further prospective study to assess the prognostic and predictive value of the BCT score is required.
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Quorum sensing (QS) enables bacteria to organize gene expression programs, thereby coordinating collective behaviors. It involves the production, release, and population-wide detection of extracellular signaling molecules. The cellular processes regulated by QS in bacteria are diverse and may be used in mutualistic coordination or in response to changing environmental conditions. Here, we focused on the influence of the QS-dependent genes of our model bacterial strain Serratia fonticola GS2 on potential plant growth promoting (PGP) activities including indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and biofilm formation. Based on genomic and phenotypic experimental data we identified and investigated the function of QS genes in the genome of the model strain. Our gene deletion study confirmed the biological functionality of the QS auto-inducer (gloI) and receptor (gloR) on potential PGP activities of GS2. A transcriptomic approach was also undertaken to understand the role of QS genes in regulation of genes primarily involved in PGP activities (IAA, ACC deaminase activity, and biofilm formation). Both transcriptomic and phenotypic data revealed that the QS-deletion mutants had considerably less PGP activities, as compared to the wild type. In addition, in vivo plant experiments showed that plants treated with GS2 had significantly higher growth rates than plants treated with the QS-deletion mutants. Overall, our results showed how QS-dependent genes regulate the potential PGP activities of GS2. This information may be helpful in understanding the relationship between QS-dependent genes and the PGP activity of bacteria, which aid in the production of practical bio-fertilizers for plant growth promotion.
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Signal transducer and activator of transcription 3 (STAT3) is a point of convergence for numerous oncogenic signals that are often constitutively activated in many cancerous or transformed cells and some stromal cells in the tumor microenvironment. Persistent STAT3 activation in malignant cells stimulates proliferation, survival, angiogenesis, invasion, and tumor-promoting inflammation. STAT3 undergoes activation through phosphorylation on tyrosine 705, which facilitates its dimerization. Dimeric STAT3 translocates to the nucleus, where it regulates the transcription of genes involved in cell proliferation, survival, etc. In the present study, a synthetic deguelin analogue SH48, discovered by virtual screening, inhibited the phosphorylation, nuclear translocation, and transcriptional activity of STAT3 in H-ras transformed human mammary epithelial MCF-10A cells (MCF10A-ras). We speculated that SH48 bearing an α,ß-unsaturated carbonyl group could interact with a thiol residue of STAT3, thereby inactivating this transcription factor. Non-electrophilic analogues of SH48 failed to inhibit STAT3 activation, lending support to the above supposition. By utilizing a biotinylated SH48, we were able to demonstrate the complex formation between SH48 and STAT3. SH48 treatment to MCF10A-ras cells induced autophagy, which was verified by staining with a fluorescent acidotropic probe, LysoTracker Red, as well as upregulating the expression of LC3II and p62. In conclusion, the electrophilic analogue of deguelin interacts with STAT3 and inhibits its activation in MCF10A-ras cells, which may account for its induction of autophagic death.
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BACKGROUND: The development and application of clinical prediction models using machine learning in clinical decision support systems is attracting increasing attention. OBJECTIVE: The aims of this study were to develop a prediction model for cardiac arrest in the emergency department (ED) using machine learning and sequential characteristics and to validate its clinical usefulness. METHODS: This retrospective study was conducted with ED patients at a tertiary academic hospital who suffered cardiac arrest. To resolve the class imbalance problem, sampling was performed using propensity score matching. The data set was chronologically allocated to a development cohort (years 2013 to 2016) and a validation cohort (year 2017). We trained three machine learning algorithms with repeated 10-fold cross-validation. RESULTS: The main performance parameters were the area under the receiver operating characteristic curve (AUROC) and the area under the precision-recall curve (AUPRC). The random forest algorithm (AUROC 0.97; AUPRC 0.86) outperformed the recurrent neural network (AUROC 0.95; AUPRC 0.82) and the logistic regression algorithm (AUROC 0.92; AUPRC=0.72). The performance of the model was maintained over time, with the AUROC remaining at least 80% across the monitored time points during the 24 hours before event occurrence. CONCLUSIONS: We developed a prediction model of cardiac arrest in the ED using machine learning and sequential characteristics. The model was validated for clinical usefulness by chronological visualization focused on clinical usability.
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BACKGROUND: A timely decision in the initial stages for patients with an acute illness is important. However, only a few studies have determined the prognosis of patients based on insufficient laboratory data during the initial stages of treatment. OBJECTIVE: This study aimed to develop and validate time adaptive prediction models to predict the severity of illness in the emergency department (ED) using highly sparse laboratory test data (test order status and test results) and a machine learning approach. METHODS: This retrospective study used ED data from a tertiary academic hospital in Seoul, Korea. Two different models were developed based on laboratory test data: order status only (OSO) and order status and results (OSR) models. A binary composite adverse outcome was used, including mortality or hospitalization in the intensive care unit. Both models were evaluated using various performance criteria, including the area under the receiver operating characteristic curve (AUC) and balanced accuracy (BA). Clinical usefulness was examined by determining the positive likelihood ratio (PLR) and negative likelihood ratio (NLR). RESULTS: Of 9491 eligible patients in the ED (mean age, 55.2 years, SD 17.7 years; 4839/9491, 51.0% women), the model development cohort and validation cohort included 6645 and 2846 patients, respectively. The OSR model generally exhibited better performance (AUC=0.88, BA=0.81) than the OSO model (AUC=0.80, BA=0.74). The OSR model was more informative than the OSO model to predict patients at low or high risk of adverse outcomes (P<.001 for differences in both PLR and NLR). CONCLUSIONS: Early-stage adverse outcomes for febrile patients could be predicted using machine learning models of highly sparse data including test order status and laboratory test results. This prediction tool could help medical professionals who are simultaneously treating the same patient share information, lead dynamic communication, and consequently prevent medical errors.
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We report a facile, but robust approach to fabricate structurally stable giant unilamellar vesicles (GUVs), on which a 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayer membrane was made rigid by introducing amphiphilic block polymers. Particularly, we found that lateral co-assembly of an amphiphilic triblock copolymer (ATC) structured with a hydrophobic middle block and long molecular weight (20â¯Kâ¯g/mol) hydrophilic end blocks remarkably enhanced the stretching modulus (k) of GUVs. When the membrane composition was optimized, the k value of ATC-hybridized GUVs increased to 6.2â¯×â¯108â¯Pa, which was approximately 10-fold higher than that of DPPC GUVs, thus leading to a much longer half-life. Moreover, we demonstrated that our ATC-hybridized GUVs enabled development of a fascinating vesicular model, which shows great potential as a structurally stable cell membrane mimic.
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1,2-Dipalmitoilfosfatidilcolina/análogos & derivados , Membrana Dobles de Lípidos/química , Liposomas/química , Polímeros/química , Liposomas Unilamelares/química , 1,2-Dipalmitoilfosfatidilcolina/química , Interacciones Hidrofóbicas e HidrofílicasRESUMEN
INTRODUCTION: Hyperprogressive disease (HPD), characterized by accelerated tumor progression, has been proposed as a new pattern of progression after immune checkpoint inhibitor (ICI) treatment. The aim of this study was to describe the characteristics of HPD and investigate its predictive markers. METHODS: Clinical and radiological findings of 335 patients with advanced NSCLC treated with ICI monotherapy were retrospectively analyzed. Radiological data were quantitatively and longitudinally analyzed for tumor size and volume by comparing baseline and follow-up computerized tomography results. The findings were matched with individual genomic profiles generated by deep sequencing of 380 genes. RESULTS: Among 135 patients with progressive disease (PD), as assessed by the Response Evaluation Criteria in Solid Tumors version 1.1 criteria, 48 (14.3% of all patients and 35.6% of those with PD) and 44 (13.1% of all patients and 32.6% among those with PD) were found to have HPD by volumetry (HPDV) and assessed by RECIST 1.1 (HPDR), respectively. Patients with HPDV were associated with significantly inferior overall survival (OS) versus that of patients without HPDV with PD (median OS = 4.7 months [95% confidence interval: 3.5-11.9)] versus 7.9 months [95% confidence interval: 6.0-13.5] [p = 0.004]); OS did not differ between patients without and without HPDR. HPDV status was an independent factor in OS. A derived neutrophil-to-lymphocyte ratio greater than 4 and lactate dehydrogenase level greater than the upper limit of normal were significantly associated with HPDV. Moreover, we identified coinciding KRAS and serine/threonine kinase 11 gene (STK11) mutations in the cohort of patients with HPDV (three of 16), whereas none were found in the cohort of patients without HPDV (zero of 28). CONCLUSIONS: Defining HPD treated with ICI on the basis of volumetric measurement is more precise than is defining it on the basis of one-dimensional analysis. Pre-ICI derived neutrophil-to-lymphocyte ratio, lactate dehydrogenase level, and concurrence of STK11 and KRAS mutations could thus be used as potential biomarkers for HPD prediction.
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Anticuerpos Monoclonales/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales/farmacología , Carcinoma de Pulmón de Células no Pequeñas/patología , Progresión de la Enfermedad , Femenino , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana EdadRESUMEN
We propose a polymeric nanovehicles (PNVs)-based enhanced transdermal delivery platform. A technical advance can be found in that delivery efficiency is significantly enhanced by effective adhesion of PNVs to the cell membrane, which is characterized noninvasively by using a confocal laser scanning microscopy (CLSM)-based skin visualization technique. To this end, the PNVs with a soft core phase were fabricated through co-assembly of two amphiphilic triblock copolymers, poly(ethylene oxide)-b-poly(ε-caprolactone)-b-poly(ethylene oxide) (PEO-b-PCL-b-PEO) and poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-b-PPO-b-PEO). The softness of PNVs was tuned successfully, while maintaining the particle size at â¼110â¯nm, by incorporation of PEO-b-PPO-b-PEO into the PNVs to a volume fraction of 0.3. Through an ex vivo skin penetration test, we showed that transactivating transcriptional activator (TAT)-decorated soft PNVs could not only exert strong adhesion to skin but also increase cellular uptake, leading to a transdermal delivery efficiency that is twice that of a hard PNV control. Moreover, CLSM-based noninvasive visualization of a fluorescent drug probe in the skin showed that the adhesiveness and softness of the PNVs contributed directly to the enhancement of transdermal delivery.
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Membrana Celular , Sistemas de Liberación de Medicamentos , Fragmentos de Péptidos/administración & dosificación , Poliésteres/administración & dosificación , Polietilenglicoles/administración & dosificación , Glicoles de Propileno/administración & dosificación , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/administración & dosificación , Adhesividad , Administración Cutánea , Animales , Línea Celular Tumoral , Humanos , Microscopía Confocal , Tamaño de la Partícula , Poliésteres/química , Polietilenglicoles/química , Glicoles de Propileno/química , Piel/metabolismo , Absorción Cutánea , PorcinosRESUMEN
BACKGROUND: The aim of this study was to compare the mean lengths of the posterior longitudinal ligament (PLL) as the acoustic window during the thoracic paramedian epidural approach after shoulder rotation, while subjects were in the lateral decubitus or in the sitting position. METHODS: Thirty-two adult male volunteers were placed in the right decubitus position or sitting position on a horizontal operating table. To obtain an optimal ultrasound view for the PLL on the right side, thoracic spinal ultrasonography was performed at the T6/7 interspace using the paramedian oblique sagittal plane. PLL length was measured on the ultrasound image before and after right shoulder rotation. RESULTS: Before shoulder rotation, the difference in mean PLL length between the sitting (11.1±1.3mm) and lateral decubitus (10.7±1.2mm) positions was not statistically significant (P=0.05). Within-position, the before and after comparison revealed that after shoulder rotation, PLL length was significantly increased to 12.2±1.4mm (P<0.001) and 12.0±1.5mm (P<0.001) in the sitting and lateral decubitus positions, respectively. However, after shoulder rotation the between-position difference in mean PLL length was not statistically significant (P=0.50) CONCLUSIONS: Shoulder rotation did not result in a statistically significant difference in the dimension of the acoustic target window for paramedian thoracic epidural access in the sitting compared to the lateral decubitus position.
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Anestesia Epidural/métodos , Ligamentos Longitudinales/diagnóstico por imagen , Posicionamiento del Paciente/métodos , Sedestación , Columna Vertebral/diagnóstico por imagen , Adulto , Voluntarios Sanos , Humanos , Ligamentos Longitudinales/anatomía & histología , Masculino , Rotación , Hombro , Columna Vertebral/anatomía & histología , Vértebras Torácicas , UltrasonografíaRESUMEN
The enzyme xylose isomerase (E.C. 5.3.1.5, XI) is responsible for the conversion of an aldose to ketose, especially xylose to xylulose. Owing to the ability of XI to isomerize glucose to fructose, this enzyme is used in the food industry to prepare high-fructose corn syrup. Therefore, we studied the characteristics of XI from Anoxybacillus kamchatkensis G10, a thermophilic bacterium. First, the gene coding for XI (xylA) was inserted into the pET-21a(+) expression vector and the construct was transformed into the Escherichia coli competent cell BL21 (DE3). The expression of recombinant XI was induced in the absence of isopropyl-thio-ß-galactopyranoside and purified using Ni-NTA affinity chromatography. The optimum temperature of recombinant XI was 80°C and measurement of the heat stability indicated that 55% of residual activity was maintained after 2 h incubation at 60°C. The optimum pH was found to be 7.5 in sodium phosphate buffer. Magnesium, manganese, and cobalt ions were found to increase the enzyme activity; manganese was the most effective. Additionally, recombinant XI was resistant to the presence of Ca²âº and Zn²âº ions. The kinetic properties, Km and Vmax, were calculated as 81.44 mM and 2.237 µmol/min/mg, respectively. Through redundancy analysis, XI of A. kamchatkensis G10 was classified into a family containing type II XIs produced by the genera Geobacillus, Bacillus, and Thermotoga. These results suggested that the thermostable nature of XI of A. kamchatkensis G10 may be advantageous in industrial applications and food processing.
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Isomerasas Aldosa-Cetosa/química , Isomerasas Aldosa-Cetosa/genética , Isomerasas Aldosa-Cetosa/metabolismo , Anoxybacillus/enzimología , Anoxybacillus/genética , Calcio/efectos adversos , Regulación Bacteriana de la Expresión Génica , Zinc/efectos adversos , Isomerasas Aldosa-Cetosa/aislamiento & purificación , Bacillus/enzimología , Secuencia de Bases , Clonación Molecular , ADN Bacteriano/genética , Activación Enzimática , Pruebas de Enzimas , Estabilidad de Enzimas , Escherichia coli/genética , Geobacillus/enzimología , Bacilos Gramnegativos Anaerobios Rectos, Curvos y Espirales/enzimología , Concentración de Iones de Hidrógeno , Cinética , Metales/efectos adversos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , TemperaturaRESUMEN
Paenibacillus donghaensis JH8T (KCTC 13049T=LMG 23780T) is a Gram-positive, mesophilic, endospore-forming bacterium isolated from East Sea sediment at depth of 500m in Korea. The strain exhibited plant cell wall hydrolytic and plant growth promoting abilities. The complete genome of P. donghaensis strain JH8T contains 7602 protein-coding sequences and an average GC content of 49.7% in its chromosome (8.54Mbp). Genes encoding proteins related to the degradation of plant cell wall, nitrogen-fixation, phosphate solubilization, and synthesis of siderophore were existed in the P. donghaensis strain JH8T genome, indicating that this strain can be used as an eco-friendly microbial agent for increasing agricultural productivity.
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Most of the commercial nighttime pedestrian detection (PD) methods reported previously utilized the histogram of oriented gradient (HOG) or the local binary pattern (LBP) as the feature and the support vector machine (SVM) as the classifier using thermal camera images. In this paper, we propose a new feature called the thermal-position-intensity-histogram of oriented gradient (TPIHOG or T π HOG) and developed a new combination of the T π HOG and the additive kernel SVM (AKSVM) for efficient nighttime pedestrian detection. The proposed T π HOG includes detailed information on gradient location; therefore, it has more distinctive power than the HOG. The AKSVM performs better than the linear SVM in terms of detection performance, while it is much faster than other kernel SVMs. The combined T π HOG-AKSVM showed effective nighttime PD performance with fast computational time. The proposed method was experimentally tested with the KAIST pedestrian dataset and showed better performance compared with other conventional methods.