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1.
Artigo em Inglês | MEDLINE | ID: mdl-33834597

RESUMO

Azolium cumulenolates are a special type of intermediates in N-heterocyclic carbene catalysis. They contain elongated linear structures with three contiguous C=C bonds and sterically unhindered α-carbon. These structure features make it difficult to develop enantioselective reactions for these intermediates. Here we disclose the first carbene-catalyzed highly enantioselective addition reactions of azolium cumulenolates. The reaction starts with alkynals as the precursors for azolium cumulenolate intermediates that undergo enantioselective addition to activated ketones. From the same set of substrates, both allene and spirooxindole products can be obtained with high yields and excellent enantioselectivities. The allene moieties in our optically enriched products carry rich reactivities and can be transformed to diverse molecules. The spirooxindole scaffolds in our products are important structural motifs in natural products and medicines.

2.
Updates Surg ; 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33797734

RESUMO

Robotic central pancreatectomy has been applied for 20 years with the advantage of minimally invasive surgery. The general pancreatic reconstruction approaches include pancreaticojejunostomy and pancreaticogastrostomy. Recently, our group reported a few preliminary cases of application of end-to-end pancreatic anastomosis in robotic central pancreatectomy. This novel approach has not been compared with the conventional approach on a large scale. The objective of this study is to compare end-to-end pancreatic anastomosis with pancreaticojejunostomy after robotic central pancreatectomy based on the perioperative and long-term outcomes. Clinical data consist of demographics, clinicopathologic characteristics, perioperative and long-term outcomes of patients who underwent robotic central pancreatectomy from March 2015 to December 2019 were collected and analyzed. Seventy-four patients received a robotic central pancreatectomy with either end-to-end pancreatic anastomosis (n = 52) or pancreaticojejunostomy (n = 22). End-to-end pancreatic anastomosis was associated with shorter operative time and reduced blood loss. Despite a higher incidence of clinically relevant postoperative pancreatic fistula (69.2% vs. 36.4%, p = 0.009), the newer anastomotic technique was also associated with earlier removal of nasogastric tube and resumption of oral intake. Long-term results, in terms of either endocrine or exocrine function, were not affected by the anastomotic technique. We have shown the feasibility of robotic central pancreatectomy with end-to-end pancreatic anastomosis. Despite streamlined technique, the newer anastomosis appears to improve early post-operative results while preserving endocrine and exocrine functions in the long-term period. Evaluation of the true potential of robotic central pancreatectomy with end-to-end pancreatic anastomosis requires a prospective and randomized study enrolling a large number of patients.

3.
Neural Netw ; 141: 11-29, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33845311

RESUMO

In deep learning tasks, the update step size determined by the learning rate at each iteration plays a critical role in gradient-based optimization. However, determining the appropriate learning rate in practice typically relies on subjective judgment. In this work, we propose a novel optimization method based on local quadratic approximation (LQA). In each update step, we locally approximate the loss function along the gradient direction by using a standard quadratic function of the learning rate. Subsequently, we propose an approximation step to obtain a nearly optimal learning rate in a computationally efficient manner. The proposed LQA method has three important features. First, the learning rate is automatically determined in each update step. Second, it is dynamically adjusted according to the current loss function value and parameter estimates. Third, with the gradient direction fixed, the proposed method attains a nearly maximum reduction in the loss function. Extensive experiments were conducted to prove the effectiveness of the proposed LQA method.

4.
J Int Med Res ; 49(4): 3000605211004386, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33845603

RESUMO

OBJECTIVE: To investigate the expression and clinical value of the E-selectin gene (SELE) in colorectal cancer (CRC). METHODS: Using gene expression profiles and clinicopathological data for patients with CRC from The Cancer Genome Atlas, and tumor and adjacent normal tissues from 31 patients with CRC from Xianyang Central Hospital, we studied the correlation between SELE gene expression and clinical parameters using Kaplan-Meier and Cox proportional hazards regression analyses. RESULTS: Higher expression of SELE was significantly associated with a poorer prognosis and shorter survival in patients with CRC. The median expression level of SELE was significantly higher in CRC tissues compared with healthy adjacent tissue. Cox regression analysis showed that the prognosis of CRC was significantly correlated with the expression of SELE. Immunohistochemical analysis also showed that positive expression of E-selectin increased significantly in line with increasing TNM stage.Conclusion: This study confirmed that SELE gene expression is an independent prognostic factor in patients with CRC.

5.
Mol Psychiatry ; 2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33863994

RESUMO

Major depressive disorder (MDD) is a complex state-dependent psychiatric illness for which biomarkers linking psychophysical, biochemical, and psychopathological changes remain yet elusive, though. Earlier studies demonstrate reduced GABA in lower-order occipital cortex in acute MDD leaving open its validity and significance for higher-order visual perception, though. The goal of our study is to fill that gap by combining psychophysical investigation of visual perception with measurement of GABA concentration in middle temporal visual area (hMT+) in acute depressed MDD. Psychophysically, we observe a highly specific deficit in visual surround motion suppression in a large sample of acute MDD subjects which, importantly, correlates with symptom severity. Both visual deficit and its relation to symptom severity are replicated in the smaller MDD sample that received MRS. Using high-field 7T proton Magnetic resonance spectroscopy (1H-MRS), acute MDD subjects exhibit decreased GABA concentration in visual MT+ which, unlike in healthy subjects, no longer correlates with their visual motion performance, i.e., impaired SI. In sum, our combined psychophysical-biochemical study demonstrates an important role of reduced occipital GABA for altered visual perception and psychopathological symptoms in acute MDD. Bridging the gap from the biochemical level of occipital GABA over visual-perceptual changes to psychopathological symptoms, our findings point to the importance of the occipital cortex in acute depressed MDD including its role as candidate biomarker.

6.
Polymers (Basel) ; 13(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806844

RESUMO

The heat generated by a high-power device will seriously affect the operating efficiency and service life of electronic devices, which greatly limits the development of the microelectronic industry. Carbon fiber (CF) materials with excellent thermal conductivity have been favored by scientific researchers. In this paper, CF/carbon felt (CF/C felt) was fabricated by CF and phenolic resin using the "airflow network method", "needle-punching method" and "graphitization process method". Then, the CF/C/Epoxy composites (CF/C/EP) were prepared by the CF/C felt and epoxy resin using the "liquid phase impregnation method" and "compression molding method". The results show that the CF/C felt has a 3D network structure, which is very conducive to improving the thermal conductivity of the CF/C/EP composite. The thermal conductivity of the CF/C/EP composite reaches 3.39 W/mK with 31.2 wt% CF/C, which is about 17 times of that of pure epoxy.

7.
Cell Immunol ; 364: 104341, 2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33798909

RESUMO

Asthma is a chronic inflammatory disease of the lungs that poses a considerable health and socioeconomic burden. Several risk factors work synergistically to affect the progression of asthma. Lipid metabolism, especially in distinct cells such as T cells, macrophages, granulocytes, and non-immune cells, plays an essential role in the pathogenesis of asthma, as lipids are potent signaling molecules that regulate a multitude of cellular response. In this review, we focused on the metabolic pathways of lipid molecules, especially fatty acids and their derivatives, and summarized their roles in various cells during the pathogenesis of asthma along with the current pharmacological agents targeting lipid metabolism.

8.
Artigo em Inglês | MEDLINE | ID: mdl-33856188

RESUMO

Electro-optic (EO) modulation is of interest to impart information onto an optical carrier. Inorganic crystals-most notably LiNbO3 and BaTiO3-exhibit EO modulation and good stability, but are difficult to integrate with silicon photonic technology. Solution-processed organic EO materials are readily integrated but suffer from thermal degradation at the temperatures required in operating conditions for accelerated reliability studies. Hybrid organic-inorganic metal halide perovskites have the potential to overcome these limitations; however, these have so far relied on heavy metals such as lead and cadmium. Here, we report linear EO modulation using metal-free perovskites, which maintain the crystalline features of the inorganic EO materials and incorporate the flexible functionality of organic EO chromophores. We find that, by introducing a deficiency of cations, we reduce the symmetry in the perovskite crystal and produce thereby an increased EO response. The best-engineered perovskites reported herein showcase an EO coefficient of 14 pm V-1 at a modulation frequency of 80 kHz, an order of magnitude higher than in the nondefective materials. We observe split peaks in the X-ray diffraction and neutron diffraction patterns of the defective sample, indicating that the crystalline structure has been distorted and the symmetry reduced. Density functional theory (DFT) studies link this decreased symmetry to NH4+ deficiencies. This demonstration of EO from metal-free perovskites highlights their potential in next-generation optical information transmission.

9.
Proc Natl Acad Sci U S A ; 118(15)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33833056

RESUMO

Embryonic stem cells (ESCs) and induced pluripotent stem cells have the potential to differentiate to all cell types of an adult individual and are useful for studying development and for translational research. However, extrapolation of mouse and human ESC knowledge to deriving stable ESC lines of domestic ungulates and large livestock species has been challenging. In contrast to ESCs that are usually established from the blastocyst, mouse expanded potential stem cells (EPSCs) are derived from four-cell and eight-cell embryos. We have recently used the EPSC approach and established stem cells from porcine and human preimplantation embryos. EPSCs are molecularly similar across species and have broader developmental potential to generate embryonic and extraembryonic cell lineages. We further explore the EPSC technology for mammalian species refractory to the standard ESC approaches and report here the successful establishment of bovine EPSCs (bEPSCs) from preimplantation embryos of both wild-type and somatic cell nuclear transfer. bEPSCs express high levels of pluripotency genes, propagate robustly in feeder-free culture, and are genetically stable in long-term culture. bEPSCs have enriched transcriptomic features of early preimplantation embryos and differentiate in vitro to cells of the three somatic germ layers and, in chimeras, contribute to both the embryonic (fetal) and extraembryonic cell lineages. Importantly, precise gene editing is efficiently achieved in bEPSCs, and genetically modified bEPSCs can be used as donors in somatic cell nuclear transfer. bEPSCs therefore hold the potential to substantially advance biotechnology and agriculture.

10.
Artigo em Inglês | MEDLINE | ID: mdl-33851519

RESUMO

Axially chiral biaryl scaffolds are prevalent in natural products, chiral ligands, and organocatalysts. However, NHC-catalyzed de novo construction of aromatic ring with concomitant axially chiral induction for the synthesis of biaryl atropisomers is far less developed, and the efficient synthesis of axially chiral tetra- ortho -substituted biaryls remains an unsolved problem under NHC catalysis. Herein, we report an NHC-catalyzed de novo synthesis of axially chiral benzothiophene/benzofuran-fused biaryls from enals and 2-benzyl-benzothiophene/benzofuran-3-carbaldehydes through a cascade strategy of [2+4] annulation, decarboxylation, and oxidative aromatization with central-to-axial chirality conversion. The developed method provides an efficient and general access to novel axially chiral benzothiophene/benzofuran-fused biaryls in high enantioselectivities and works well for the synthesis of tetra- ortho -substituted biaryls.

11.
Polymers (Basel) ; 13(5)2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668296

RESUMO

Because the aerogel has ultra-low density and good impact resistance, the aerogel material, epoxy-hardener system, and expandable polystyrene beads (EPS) were used to prepare the lightweight aerogel reinforced hollow epoxy macro-spheres (AR-HEMS). The multi-phase epoxy syntactic foam (ESF) was manufactured with the epoxy-hardener system, HGMS (EP-hardener-HGMS), and AR-HEMS by "the compression modeling method." In this experiment, in order to enhance the strength of the ESF, some different kinds of the carbon fiber (CF) were added into the EP-hardener-HGMS system (CFR-EP). The influence of the volume stacking fraction, inner diameter, and layer of the AR-HEMS and the content and type of the CF in the EP-HGMS (CFR-EP) system on the compressive strength of the ESF were studied. Weighing the two factors of the density and compressive strength, the ESF reinforced by 1.5 wt% CF with 90% AR-HEMS has the better performance. This kind of the ESF has 0.428 g/cm3 nd 20.76 Mpa, which could be applied in 2076 m deep sea.

12.
Artigo em Inglês | MEDLINE | ID: mdl-33720683

RESUMO

Two-dimensional materials such as graphene and transition metal dichalcogenides (TMDCs) have received extensive research interest and investigations in the past decade. In this research, we used a refined opto-thermal Raman technique to explore the thermal transport properties of one popular TMDC material WSe2, in the single-layer (1L), bilayer (2L), and trilayer (3L) forms. This measurement technique is direct without additional processing to the material, and the absorption coefficient of WSe2 is discovered during the measurement process to further increase this technique's precision. By comparing the sample's Raman spectroscopy spectra through two different laser spot sizes, we are able to obtain two parameters-lateral thermal conductivities of 1L-3L WSe2 and the interfacial thermal conductance between 1L-3L WSe2 and the substrate. We also implemented full-atom nonequilibrium molecular dynamics simulations (NEMD) to computationally investigate the thermal conductivities of 1L-3L WSe2 to provide comprehensive evidence and confirm the experimental results. The trend of the layer-dependent lateral thermal conductivities and interfacial thermal conductance of 1L-3L WSe2 is discovered. The room-temperature thermal conductivities for 1L-3L WSe2 are 37 ± 12, 24 ± 12, and 20 ± 6 W/(m·K), respectively. The suspended 1L WSe2 possesses a thermal conductivity of 49 ± 14 W/(m·K). Crucially, the interfacial thermal conductance values between 1L-3L WSe2 and the substrate are found to be 2.95 ± 0.46, 3.45 ± 0.50, and 3.46 ± 0.45 MW/(m2·K), respectively, with a flattened trend starting the 2L, a finding that provides the key information for thermal management and thermoelectric designs.

13.
J Synchrotron Radiat ; 28(Pt 2): 650-665, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33650577

RESUMO

Two new macromolecular crystallography (MX) beamlines at the National Synchrotron Light Source II, FMX and AMX, opened for general user operation in February 2017 [Schneider et al. (2013). J. Phys. Conf. Ser. 425, 012003; Fuchs et al. (2014). J. Phys. Conf. Ser. 493, 012021; Fuchs et al. (2016). AIP Conf. Proc. SRI2015, 1741, 030006]. FMX, the micro-focusing Frontier MX beamline in sector 17-ID-2 at NSLS-II, covers a 5-30 keV photon energy range and delivers a flux of 4.0 × 1012 photons s-1 at 1 Šinto a 1 µm × 1.5 µm to 10 µm × 10 µm (V × H) variable focus, expected to reach 5 × 1012 photons s-1 at final storage-ring current. This flux density surpasses most MX beamlines by nearly two orders of magnitude. The high brightness and microbeam capability of FMX are focused on solving difficult crystallographic challenges. The beamline's flexible design supports a wide range of structure determination methods - serial crystallography on micrometre-sized crystals, raster optimization of diffraction from inhomogeneous crystals, high-resolution data collection from large-unit-cell crystals, room-temperature data collection for crystals that are difficult to freeze and for studying conformational dynamics, and fully automated data collection for sample-screening and ligand-binding studies. FMX's high dose rate reduces data collection times for applications like serial crystallography to minutes rather than hours. With associated sample lifetimes as short as a few milliseconds, new rapid sample-delivery methods have been implemented, such as an ultra-high-speed high-precision piezo scanner goniometer [Gao et al. (2018). J. Synchrotron Rad. 25, 1362-1370], new microcrystal-optimized micromesh well sample holders [Guo et al. (2018). IUCrJ, 5, 238-246] and highly viscous media injectors [Weierstall et al. (2014). Nat. Commun. 5, 3309]. The new beamline pushes the frontier of synchrotron crystallography and enables users to determine structures from difficult-to-crystallize targets like membrane proteins, using previously intractable crystals of a few micrometres in size, and to obtain quality structures from irregular larger crystals.

14.
Bosn J Basic Med Sci ; 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33714257

RESUMO

Ferroptosis is a form of iron-dependent programmed cell death. Regulation of ferroptosis in tumor cells is a novel treatment modality. The present study aimed to investigate ferroptosis-related long non-coding RNAs (lncRNAs) and construct a prognostic model for colon adenocarcinoma (COAD). RNA- sequencing data and ferroptosis-related genes were obtained from The Cancer Genome Atlas database and FerrDb database. COAD patients were randomly assigned to training- and validation groups. The Least Absolute Shrinkage and Selection Operator regression and Cox regression model were used to determine and develop a predictive model. The model was corroborated using the validation group and the entire group. In total, 259 ferroptosis-related genes and 905 ferroptosis-related LncRNAs were obtained. Cox model revealed and constructed seven ferroptosis-related LncRNAs signature (LINC01503, AC004687.1, AC010973.2, AP001189.3, ARRDC1-AS1, OIP5-AS1, and NCK1-DT). Patients were assigned into two groups according to the median risk score. Kaplan-Meier survival curves showed that overall survival between high- and low-risk groups was statistically significant (P<0.01). Cox multivariate analysis seven ferroptosis-related LncRNAs signature was an independent risk factor for COAD outcomes (P<0.05). The relationship between seven ferroptosis-related LncRNAs and clinicopathological features was also examined. The principal component analysis showed a difference between high- and low-risk groups intuitively. With the aid of gene set enrichment analysis, the underlying mechanisms of seven ferroptosis-related LncRNAs were uncovered, including the MAPK signaling pathway, mTOR signaling pathway, and glutathione metabolism pathway. Finally, we established and validated seven ferroptosis-related lncRNAs signature for COAD patients to predict survival. These results may provide meaningful targets for future study.

15.
J Cell Sci ; 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33648936

RESUMO

Membrane contact sites (MCSs) between endoplasmic reticulum (ER) and late endosomes/lysosomes (LE/lys) are emerging as critical hubs for diverse cellular events, and changes in their extents are linked to severe neurological diseases. While recent studies show that synaptotagmin-like mitochondrial-lipid-binding (SMP) domain-containing protein PDZD8 may mediate the ER-LE/lys MCSs, the cellular functions of PDZD8 remain largely elusive. Here we attempt to investigate lipid transfer activities of PDZD8 and the extent to which its cellular functions depend on its lipid transfer activities. In accordance with recent studies, we demonstrate that PDZD8 is a Protrudin-interacting protein and PDZD8 acts as a tether at ER-LE/lys MCSs. Further, we discover that the SMP domain of PDZD8 binds glycerophospholipids and ceramides both in vivo and in vitro, and the SMP domain can transport lipids between membranes in vitro Functionally, PDZD8 is required for LE/lys positioning and neurite outgrowth, which is dependent on the lipid transfer activity of the SMP domain.

16.
Gene ; 785: 145602, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33766712

RESUMO

T-box transcription factor 3 (TBX3) gene encodes a transcriptional suppressor and plays an important role in embryonic development, which belongs to the T-box family. TBX3 also has been found to be associated with body size traits in horse that is a relative of donkey. Therefore, TBX3 is considered as a promising candidate gene for economic traits of donkey. This study aimed to reveal the significant variation of TBX3 gene in Dezhou donkey and explores the relationship between genotypes and body sizes. In this study, an A > G mutation was found in the intron 2 of TBX3 gene by sequencing, and three genotypes (AA, GG and AG) were identified in 380 Dezhou donkey individuals with Tm-shift method. Association analysis illustrated that there were significant differences between AA and GG genotype in body length, body height, chest depth, chest circumference, body weight, hucklebone width and rump length. Our results demonstrated that the polymorphism of TBX3 is significantly associated with body size traits, which can serve as a marker to improve donkey production performance.

17.
Am J Med Sci ; 361(4): 499-508, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33775424

RESUMO

BACKGROUND: It has been reported that the dysregulation of microRNAs (miRNAs) is implicated in the biological processes of diverse diseases, including the tumorigenesis of human cancers. MicroRNA-628-5p (miR-628-5p) is differentially expressed and plays a critical role in several cancers, but the role of miR-628-5p in cervical cancer has not been well studied. METHODS: The TCGA database and RT-qPCR were used to evaluate the expression profile of miR-628-5p in cervical cancer tissues. Transfection efficiency of synthetic miRNAs was detected using RT-qPCR. The biological effects of miR-628-5p on cervical cancer cells were assessed by the CCK-8 assay, flow cytometry, western blot analysis, and the tube formation assay. The expression levels of key proteins involved in cell apoptosis, the cell cycle and the PI3K pathway were analyzed by western blot analysis. Bioinformatic analysis and the luciferase reporter assay were performed to investigate the targeted relationship between miR-628-5p and vascular endothelial growth factor (VEGF). RESULTS: MiR-628-5p was downregulated and negatively correlated with Ki-67 expression in cervical cancer tissues, and its low level predicted poor survival of patients. Functional assays indicated that miR-628-5p inhibited cell proliferation and promoted cell apoptosis. Mechanically, VEGF was verified to be a downstream target of miR-628-5p. Moreover, overexpression of VEGF could reverse the effects of miR-628-5p on VEGF/PI3K/AKT signaling, cell proliferation, apoptosis, the cell cycle and angiogenesis in cervical cancer. CONCLUSIONS: MiR-628-5p inhibited cervical cancer cell proliferation and promoted apoptosis by targeting VEGF.

18.
Emerg Microbes Infect ; 10(1): 612-618, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33703996

RESUMO

Phage therapy is recognized as a promising alternative to antibiotics in treating pulmonary bacterial infections, however, its use has not been reported for treating secondary bacterial infections during virus pandemics such as coronavirus disease 2019 (COVID-19). We enrolled 4 patients hospitalized with critical COVID-19 and pulmonary carbapenem-resistant Acinetobacter baumannii (CRAB) infections to compassionate phage therapy (at 2 successive doses of 109 plaque-forming unit phages). All patients in our COVID-19-specific intensive care unit (ICU) with CRAB positive in bronchoalveolar lavage fluid or sputum samples were eligible for study inclusion if antibiotic treatment failed to eradicate their CRAB infections. While phage susceptibility testing revealed an identical profile of CRAB strains from these patients, treatment with a pre-optimized 2-phage cocktail was associated with reduced CRAB burdens. Our results suggest the potential of phages on rapid responses to secondary CRAB outbreak in COVID-19 patients.

19.
Aging (Albany NY) ; 13(6): 7733-7744, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33735106

RESUMO

BACKGROUND: The novel coronavirus infectious disease (COVID-19) is an international concern as it spreads through human populations and across national and international borders. METHODS: In this retrospective study, we consecutively included all cancer patients who had been identified as having a nucleic acid-confirmed COVID-19 from two designated hospitals in Wuhan, China. COVID-19 patients without cancer were also enrolled for comparison. The clinical data were gathered from the medical records from Jan 14 to March 12, 2020. RESULTS: Among the 117 cancer patients diagnosed with COVID-19, the median age was 63 years and 48.7% were male. Male sex, hematologic cancer, dyspnea on admission, and anti-cancer therapies were associated with an increased risk of mortality in cancer patients with COVID-19. We found that elevated levels of TNF-α, IL-2R, IL-6, and IL-8 were associated with a poorer prognosis in cancer patients with COVID-19, but no statistically significant association was found in patients without cancer. In addition, IL-2R and IL-6 markedly decreased in cancer patients who recovered from COVID-19. However, lymphocyte subsets were diminished in cancer patients who died from COVID-19, including total T cells, total B cells, helper T (Th) cells and suppressor T (Ts) cells. CONCLUSIONS: Cancer patients with COVID-19 were associated with high mortality (23.9%). A decrease in lymphocyte subsets and higher levels of cytokines were associated with a higher risk of severe outcome and could be utilized as the reference index to predict the survival outcome of cancer patients with COVID-19.

20.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 43(1): 53-56, 2021 Feb 28.
Artigo em Chinês | MEDLINE | ID: mdl-33663663

RESUMO

Objective To compare the differences of energy spectrum CT between small cell lung cancer(SCLC)with mediastinal lymph node metastasis and mediastinal sarcoidosis.Methods Twenty-five SCLC patients with mediastinal lymph node metastasis(SCLC group)and 26 patients with mediastinal sarcoidosis(sarcoidosis group)confirmed by bronchoscopy and biopsy in Tangshan People's Hospital from January 2018 to June 2019 were selected as the research objects.The CT value,iodine concentration,water concentration and energy spectrum curve slope under different single energy levels were compared between SCLC group and sarcoidosis group.Results The single-energy CT values of 40-80 keV segments in the arterial phase of the SCLC group were significantly higher than those in the sarcoidosis group(all P <0.05).The single-energy CT values of 90-140 keV segments were not significantly different from those in the sarcoidosis group(all P >0.05).The single-energy CT values of 40-90 keV segments in venous phase of the SCLC group were significantly higher than those of the sarcoidosis group(all P <0.05),and the single-energy CT values of 100-140 keV segments were not significantly different from those of the sarcoidosis group(all P >0.05).The concentrations of iodine in the arterial phase and venous phase of the SCLC group were(11.56±4.06)µg/cm 3 and(13.39±0.87)µg/cm 3,respectively,which were significantly higher than those [(4.43±3.85)µg/cm 3,t=11.564,P=0.026;(7.23±2.71)µg/cm 3,t=13.653,P=0.021] in the sarcoidosis group.The concentrations of water in the arterial and venous phases of the SCLC group were(1040.67±5.62)mg/cm 3 and(1035.23±8.57)mg/cm 3,respectively,which showed no statistically significant difference compared with those [(1028.87±6.94)mg/cm 3,t=3.155,P=1.861;(1021.53±4.68)mg/cm 3,t=3.265,P=1.687] in the sarcoidosis group.The slopes of energy spectrum curve at 40-70 keV,70-100 keV and 100-140 keV in venous phase of the SCLC group were significantly higher than those of the sarcoidosis group(all P <0.05),whereas they showed no significant difference between the two groups in arterial phase(all P >0.05).Conclusion The differences between SCLC with mediastinal lymph node metastasis and mediastinal sarcoidosis can be shown on the single-energy CT values of 40-80 keV in arterial phase and 40-90 keV in venous phase,iodine concentrations in arterial phase and venous phase,and the slope of energy spectrum curve in venous phase.

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