Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.288
Filtrar
1.
Waste Manag ; 119: 82-90, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33049516

RESUMO

Inhibition mechanisms of sulfur-, nitrogen- and phosphorus- based inhibitors on the de novo synthesis of polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/F) were studied by exploring speciation evolution of carbon, chorine and copper in fly ash under laboratory-scale experiments. Significant inhibition of PCDD/Fs by thiourea (TUA) and ammonium dihydrogen phosphate (ADP) was observed as 97.2% and 98.2%, respectively, except for potassium dihydrogen phosphate (PDP). ADP and PDP exhibited better inhibition on PCDFs than on PCDDs, whereas TUA exhibited the opposite effect. After adding inhibitors, the proportion of C-O/C=O/O-C=O bonds at the surface of fly ash increased, and stronger oxidation of carbon occurred, together with the conversion from Cu2+ to Cu+ and the inhibition of organic chlorine formation. Kinetic model results indicated that TUA might either suppress the carbon gasification or promote the decomposition of PCDD/Fs, resulting in a remarkable inhibition of PCDD/Fs formation. Simulated chemical reaction equilibrium further comfirmed that catalytic metal could be deactivated into CuS and Cu2S by sulfur, and into Cu2P2O7 by phosphorus. Moreover, NH3, decomposed from TUA and ADP, was able to convert Cl2 into HCl, albeit with a weaker chlorination ability. This study of inhibition mechanisms is useful for the exploration and utilization of efficient inhibitors in full-scale incinerators.

2.
Phys Rev Lett ; 125(15): 155702, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33095607

RESUMO

High-pressure metallic ß-Sn silicon (Si-II), depending on temperature, decompression rate, stress, etc., may transform to diverse metastable forms with promising semiconducting properties under decompression. However, the underlying mechanisms governing the different transformation paths are not well understood. Here, two distinctive pathways, viz., a thermally activated crystal-crystal transition and a mechanically driven amorphization, were characterized under rapid decompression of Si-II at various temperatures using in situ time-resolved x-ray diffraction. Under slow decompression, Si-II transforms to a crystalline bc8/r8 phase in the pressure range of 4.3-9.2 GPa through a thermally activated process where the overdepressurization and the onset transition strain are strongly dependent on decompression rate and temperature. In comparison, Si-II collapses structurally to an amorphous form at around 4.3 GPa when the volume expansion approaches a critical strain via rapid decompression beyond a threshold rate. The occurrence of the critical strain indicates a limit of the structural metastability of Si-II, which separates the thermally activated and mechanically driven transition processes. The results show the coupled effect of decompression rate, activation barrier, and thermal energy on the adopted transformation paths, providing atomistic insight into the competition between equilibrium and nonequilibrium pathways and the resulting metastable phases.

3.
Clin Chim Acta ; 511: 90-93, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33031805

RESUMO

BACKGROUND AND OBJECTIVES: To examine anti-platelet autoantibodies in patients with immune thrombocytopenia (ITP) not only provides solid evidence for diagnosis, and also helps to select an individualized strategy for the treatment. The aim of this study is to develop a novel cell-based assay to detect autoantibodies in ITP patients. METHODS/PATIENTS: The DNA sequences of human platelet membrane protein GPIbα, GPIbß, GP IX, GPIIb and GPIIIa subunits were obtained from NCBI database and synthesized. The synthetic fragments were ligated into pcDNA 3.3 and constructed the recombinant plasmids and transfected into Chinese hamster ovary (CHO) cells to establish cell lines stable expressing GPIb-IX and/or GPIIb/IIIa complexes. One hundred and two ITP patients with different anti-platelet autoantibodies, 57 patients with other kinds of autoimmune diseases and 104 healthy control were selected to examine sensitivity, specificity and accuracy of this method. RESULTS: CHO cells stable expressing GPIb-IX and/or GPIIb/IIIa proteins were established. The cells were fixed with 4% paraformaldehyde and stored at -80 ℃, more than 80% of the cells were still expressed target proteins after 180 days of storage. The concentrations of target antibody from 0.1 to 100 µg/ml were detectable by this method, and 10-50 µg/ml antibody binding to the CHO cells yielded higher distinguishable fluorescent intensities. Inter-assay and intra-assay coefficients of variation and receiver operating characteristic curve analysis showed that this method had relatively higher reproducibility and specificity. Compared with Flow Cytometric Immunobead Array, this method has relatively higher specificity (95.2%) and accuracy (90.8%) in detection of 102 ITP patients. CONCLUSION: A novel cell-based assay to detect autoantibodies in ITP patients is established, which appears to be a promising method to diagnose ITP.

4.
Chemosphere ; 264(Pt 2): 128542, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33059280

RESUMO

Open burning of PVC-coated cables is a major source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F). In the present study, the formation characteristics of PCDD/F from burning of PVC-based samples with and without metallic copper were evaluated over the dioxin formation temperature window (200-500 °C). This temperature range also inevitably occurs under open burning conditions. The PCDD/F yield from PVC added with Cu increased by factors of 1390 (300 °C), 65 (400 °C) and 17 (500 °C) compared with that from PVC alone, confirming the stimulatory effect of metallic Cu on PCDD/F production. For the first time, a relatively complete isomer-specific analysis is established for PVC acting as source of PCDD/F. Formation pathways of PCDD/F and the reaction mechanisms were investigated using a combined analysis of PCDD/F isomer signatures, thermogravimetric results and Cl K-edge X-ray absorption spectra. De novo synthesis is the major pathway leading to massive production of PCDD/F. Copper extends the temperature range for the concurrence of de(hydro)chlorination of PVC with cross-linking and aromatisation of polyenes and then stimulates cracking of the chlorine-embedded carbon network. Together, these processes contribute to the strongly enhanced formation of PCDD/F via de novo synthesis.

5.
Abdom Radiol (NY) ; 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33074424

RESUMO

PURPOSE: To assess the value of various diffusion parameters obtained from monoexponential, biexponential, and stretched-exponential diffusion-weighted imaging (DWI) models for staging hepatic fibrosis (HF) and grading inflammatory activity in patients with chronic hepatitis B (CHB). METHODS: 82 patients with CHB and 30 healthy volunteers underwent DWI with 13 b-values on a 3T MRI unit. The standard apparent diffusion coefficient (ADCst) was calculated using a monoexponential model. The true diffusion coefficient (Dt), pseudo-diffusion coefficient (Dp), and perfusion fraction (f) were calculated using a biexponential model. The distributed diffusion coefficient (DDC) and water-molecule diffusion heterogeneity index (α) were calculated using a stretched-exponential model. Receiver operating characteristic (ROC) curves were performed for diffusion parameters to compare the diagnosis performance. RESULTS: The distributions of hepatic fibrosis stages and the inflammatory activity grades (METAVIR scoring system) were as follows: F0, n = 1; F1, n = 16; F2, n = 31; F3, n = 19; and F4, n = 15. A0, n = 1; A1, n = 14; A2, n = 46; and A3, n = 21. ADCst, Dt and DDC values showed negative correlation with the fibrosis stage (r = - 0.418, - 0.717 and - 0.630, all P < 0.001) and the inflammatory activity grade (r = - 0.514, - 0.626 and - 0.550, all P < 0.001). The area under the ROC curve (AUC) of Dt (AUC = 0.854, 0.881) and DDC (AUC = 0.794, 0.834) were significantly higher than that of ADCst (AUC = 0.637, 0.717) in discriminating significant fibrosis (≥ F2) and advanced fibrosis (≥ F3) (all P < 0.05). Although Dt (AUC = 0.867, 0.836) and DDC (AUC = 0.810, 0.808) showed higher AUCs than ADCst (AUC = 0.767, 0.803), there was no significant difference in their ability in detecting inflammatory activity grade ≥ A2/A3 (P > 0.05). CONCLUSIONS: Dt and DDC are promising indicators and outperform ADCst for staging HF. While both Dt and DDC have similar diagnostic performance compared with ADCst for grading inflammatory activity.

6.
J Mater Chem B ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33078180

RESUMO

Combining photothermal therapy (PTT) and multimodality molecular imaging into one nanotheranostic can improve the diagnostics and therapeutics outcome of malignant tumors significantly. Herein, a heteronanostructure (named Au-Fe3O4@PDA-PEG-DTPA-Gd) has been synthesized for multimodality molecular imaging-guided PTT by conjugation of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) on a polydopamine (PDA) coated Au-Fe3O4 heterodimeric via a polyethylene glycol (PEG) crosslinker. Au-Fe3O4@PDA-PEG-DTPA-Gd exhibits reasonable biocompatibility, high photothermal conversion efficiency (η = 41.3%), integration of excellent T1-/T2-weighted magnetic resonance imaging (MRI, the molar longitudinal relaxivity rate (r1) = 6.14 mM-1 s-1/transverse relaxation rate (r2) = 71.88 mM-1 s-1) and X-ray computed tomography imaging (CT, approximately 1.94 times higher than that of the commercial CT contrast agent ioversol) contrast functionality. The theranostic capability of Au-Fe3O4@PDA-PEG-DTPA-Gd has been verified on the triple negative breast tumor cell (MDA-MB-231 cell) and MDA-MB-231 tumor-bearing mouse model. From MR/CT imaging, Au-Fe3O4@PDA-PEG-DTPA-Gd shows remarkable PTT efficacy, which completely inhibits MDA-MB-231 tumor growth in vivo with a single treatment.

7.
Sci Rep ; 10(1): 16700, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028908

RESUMO

Trace metal contamination in the aquatic ecosystem occurs worldwide: although copper is an essential trace metal, it is considered as a pollutant at certain levels in China. Freshwater crayfish Cambaroides dauricus is a commercially important wild species in northeastern China, in which is an important heavy industry area. The population of C. dauricus was decreasing sharply due to the environmental pollution and human intervention over the past 20 years. However, nothing is known regarding the responses of this species to trace metal toxicants. This study aimed to determine the acute and chronic toxicity of Cu and its toxicological effects on respiratory metabolism, as well as Cu accumulation in C. dauricus. The acute (96 h) median lethal concentration (LC50) value of 32.5 mg/L was detected in C. dauricus. Then, acute (96 h; 8.24, 16.48 mg/L) and sub-chronic (14 days; 2.06, 4.12 mg/L) exposure in Cu was investigated by estimating the oxygen consumption rate, ammonium excretion rate, and Cu accumulation. Both acute and sub-chronic Cu exposure induced an inhibition of the oxygen consumption rate and ammonium excretion rate, and thereby, an increased O:N ratio. The shift in O:N ratio indicated a metabolic substrate shift towards lipid and carbohydrate metabolism under Cu stress. Cu accumulation in the hepatopancreas and muscles throughout the study was found to be time-dependent and concentration-dependent. The maximum accumulation in the hepatopancreas and muscle were almost 31.6 folds of the control after 14 days' exposure to 4.12 mg/L concentration. Based on the present work, we suggest that crayfish be considered a potential bioindicator of environmental pollution in freshwater systems. The study provides basic information for further understanding of the toxicological responses of this species to trace metals.

8.
Eur J Neurol ; 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33030300

RESUMO

BACKGROUND: Falling is considered an important public health problem among older people. A cross-sectional study suggested that cognitive frailty is associated with falls. We explored whether cognitive frailty is a risk factor for falls in this population-based longitudinal study. METHODS: In this study, data of the Rugao Longevity and Aging Study were used. The modified Fried's phenotype was used to assess physical frailty, and the 20% of participants with the lowest scores on the Revised Hasegawa Dementia Scale were defined as cognitive impairment (CoI). Cognitive frailty (CF) was defined as the coexistence of physical frailty and cognitive impairment, but exclude the severe cognitive impairment (HDS-R≤10). Number of falls in the previous 12 months were measured by questionnaire. RESULTS: At baseline, the prevalence of CF was 2.6% and the prevalence of two or more falls was 6.7%. Cross-sectional analysis found that two or more falls were associated with physical frailty without CoI(OR=6.79,95%CI=3.17-14.56), pre-frailty with CoI(OR=4.54,95%CI=2.44-8.44) and CF (OR=3.51,95%CI=1.18-10.44). Slow gait with cognitive impairment were associated with two or more falls (OR=2.21,95%CI=1.08-4.53). At 3-year follow-up survey, the prevalence of two or more falls was 10.6 %. Logistic regression analysis showed that, compared with the robust and non-CoI elderly, the CF elderly had a higher risk of two or more falls (OR=3.41,95%CI=1.11-10.50). CONCLUSIONS: Cognitive frailty was associated with two or more falls at baseline and might be a risk factor for two or more falls after three years. Early screening of cognitive frailty might be beneficial to the prevention of falls.

9.
Int J Nanomedicine ; 15: 6593-6603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982220

RESUMO

Purpose: Micro-arc oxidation (MAO) is a fast and effective method to prepare nanoporous coatings with high biological activity and bonding strength. Simple micro/nano-coatings cannot fully meet the requirements of osteogenesis. To further improve the biological activity of a titanium surface, we successfully added biological magnesium (Mg2+) to a coating by micro-arc oxidation and evaluated the optimal magnesium concentration in the electrolyte, biocompatibility, cell adhesion, proliferation, and osteogenesis in vitro. Methods: Nanoporous titanium coatings with different concentrations of magnesium were prepared by micro-arc oxidation and characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The Mg2+ release ability of the magnesium-incorporated nanoporous titanium coatings was determined by inductively coupled plasma emission spectrometry (ICP-OES). The cytotoxicity of the magnesium-incorporated nanoporous titanium coatings was detected with live/dead double-staining tests. A CCK-8 assay was employed to evaluate cell proliferation, and FITC-phalloidin was used to determine the structure of the cytoskeleton by staining ß-actin. Alkaline phosphatase (ALP) activity was evaluated by alizarin red S (ARS) staining to determine the effect of the coatings on osteogenic differentiation in vitro. The mRNA expression of osteogenic differentiation-related markers was measured using qRT-PCR. Results: EDS analyses revealed the successful addition of magnesium to the microporous coatings. The best magnesium concentration of the electrolyte for preparing the new coating was determined. The results showed that the nano-coatings prepared using the electrolyte with 2 g/L magnesium acetate best promoted the adhesion, proliferation, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Conclusion: These results suggest that the new titanium metal coating with a dual effect of promoting bone morphology and supplying the biological ion Mg2+ can be beneficial for rapid osseointegration.

10.
Hum Pathol ; 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32991930

RESUMO

GATA3 immunostain is a sensitive marker for mammary and urothelial carcinomas. It is routinely used in surgical pathology during workup of carcinomas of unknown origin. To the best of our knowledge, this is the first focused study of GATA3 expression in gallbladder adenocarcinomas. In this study we evaluated GATA3 expression in 38 gallbladder adenocarcinomas. 8 of 38 (21%) gallbladder adenocarcinomas were positive for GATA3. The expression of GATA3 tended to be moderate to strong when present. It was patchy (<50% positivity) in 4 cases, characterized by discrete clusters or groups of malignant cells with areas of intervening negative tumor cells whereas it was diffuse (>50% positivity) in the other 4 cases. GATA3 expression did not show any significant correlation with clinicopathologic features such as sex, histologic grade, perineural invasion, vascular invasion, pathologic stage or distance metastasis. The results of our study show that a subset of gallbladder adenocarcinomas (21%) can be GATA3 positive. Awareness of this phenomenon is important while working up GATA3 positive carcinomas immunohistochemically.

11.
Front Med ; 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32926319

RESUMO

Coronavirus disease 2019 (COVID-19) is now pandemic worldwide and has heavily overloaded hospitals in Wuhan City, China during the time between late January and February. We reported the clinical features and therapeutic characteristics of moderate COVID-19 cases in Wuhan that were treated via the integration of traditional Chinese medicine (TCM) and Western medicine. We collected electronic medical record (EMR) data, which included the full clinical profiles of patients, from a designated TCM hospital in Wuhan. The structured data of symptoms and drugs from admission notes were obtained through an information extraction process. Other key clinical entities were also confirmed and normalized to obtain information on the diagnosis, clinical treatments, laboratory tests, and outcomes of the patients. A total of 293 COVID-19 inpatient cases, including 207 moderate and 86 (29.3%) severe cases, were included in our research. Among these cases, 238 were discharged, 31 were transferred, and 24 (all severe cases) died in the hospital. Our COVID-19 cases involved elderly patients with advanced ages (57 years on average) and high comorbidity rates (61%). Our results reconfirmed several well-recognized risk factors, such as age, gender (male), and comorbidities, as well as provided novel laboratory indications (e.g., cholesterol) and TCM-specific phenotype markers (e.g., dull tongue) that were relevant to COVID-19 infections and prognosis. In addition to antiviral/antibiotics and standard supportive therapies, TCM herbal prescriptions incorporating 290 distinct herbs were used in 273 (93%) cases. The cases that received TCM treatment had lower death rates than those that did not receive TCM treatment (17/273 = 6.2% vs. 7/20= 35%, P = 0.0004 for all cases; 17/77= 22% vs. 7/9= 77.7%, P = 0.002 for severe cases). The TCM herbal prescriptions used for the treatment of COVID-19 infections mainly consisted of Pericarpium Citri Reticulatae, Radix Scutellariae, Rhizoma Pinellia, and their combinations, which reflected the practical TCM principles (e.g., clearing heat and dampening phlegm). Lastly, 59% of the patients received treatment, including antiviral, antibiotics, and Chinese patent medicine, before admission. This situation might have some effects on symptoms, such as fever and dry cough. By using EMR data, we described the clinical features and therapeutic characteristics of 293 COVID-19 cases treated via the integration of TCM herbal prescriptions and Western medicine. Clinical manifestations and treatments before admission and in the hospital were investigated. Our results preliminarily showed the potential effectiveness of TCM herbal prescriptions and their regularities in COVID-19 treatment.

12.
J Chromatogr A ; 1629: 461510, 2020 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-32889298

RESUMO

A two-dimensional system composed of supercritical fluid chromatography (SFC) and reverse phase liquid chromatography (RPLC) coupled a tandem mass spectrometry (MS) was developed for the quantitative analysis of vitamin D in daily oily supplements. Two six-port switching valves are configured, allowing four different valve positions. When the valve positions were fixed at Position A, this system worked at SFC-MS mode. When the valve positions switched between Position B and C, this system worked at a SFC-LC-MS switching mode. Vitamin D3 in two kinds of oily drops, Baby Ddrops and Vitamin AD drops, was determined at both SFC-MS and SFC-LC-MS switching modes by using the same system. The linearity, repeatability and recovery were investigated using the internal and external standard methods for the two modes. The results obtained from the internal standard method are better than those of the external standard method at either mode. The coefficient of determination (r2) for the internal standard method is more than 0.999, with a linear range of 20-1000 µg/L. Both Baby Ddrops and Vitamin AD drops were analyzed with good repeatability (<3.21%) and recovery (94.1%-116.1%) using internal standard method. When calculated by the external standard method, as compared to SFC-MS mode, SFC-LC-MS switching mode has better linearity (r2>0.999), repeatability (Baby Ddrops: 4.45%, Vitamin AD drops: 1.12%) and recovery (86.3%-107.1%). The results indicate that the two-dimensional SFC-MS/SFC-LC-MS system is useful for determination of vitamin D in oily drops. If it works at SFC-MS mode, the internal standard is required. When SFC-LC-MS switching mode is used, external standard method can also obtain the accurate results with good precision.

13.
J Phycol ; 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32888200

RESUMO

Studies of quantitative trait loci based on genetic linkage maps require the establishment of a mapping population. Permanent mapping populations are more ideal than temporary ones because they can be used repeatedly. However, there has been no reported permanent sporophyte population of economically important kelp species. Based on the characteristics of the kelp life cycle, we proposed a method to establish, and then constructed experimentally, an "immortalized F2 " (IF2 ) population of Undaria pinnatifida. Doubled haploid "female" and "male" sporophytes were obtained through the parthenogenesis of a female gametophyte clone and the selfing of a "monoecious" gametophyte clone (originally male), respectively, and they were used as the parents. The F1 hybrid line was generated by crossing the female and male gametophytes derived from the respective female and male parents. Full-sibling F2 gametophyte clones, consisting of 260 females and 260 males, were established from an F1 hybrid sporophyte. Thirty-five females and 35 males were randomly selected and paired to give rise to an IF2 population containing 35 crossing lines. A parentage analysis using 10 microsatellite markers confirmed the accuracy of the IF2 population and indicated the feasibility of this method. This proposed method may be adapted for use in other kelp species, and thus, it will be useful for genetic studies of kelp.

14.
Curr Drug Deliv ; 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32940178

RESUMO

BACKGROUND: Development of controlled drug delivery systems can improve the pharmacokinetic characteristics of drug molecules in the human body, thereby significantly improving the utilization rate of drugs and reducing toxicity and side effects caused by high concentrations of drugs, which can occur when delivery is not controlled. Metal organic frameworks are a new class of very promising crystalline microporous materials, especially when the size is reduced to the nanometer range. Metal organic frameworks exhibit large specific surface areas, tunable compositions, and easy functionalization. In recent years, increasing number of studies have reported the remarkable advances in multifunctional nanoscale metal organic frameworks in drug delivery. OBJECTIVE: Review the latest research involving advances in stimuli-responsive nanoscale metal organic frameworks as drug delivery systems in controlled-release drugs. DISCUSSION: We first introduce the two main strategies associated with nanoscale metal organic frameworks used in drug loading: direct assembly and post-encapsulation. We next focus on the latest discoveries of nanoscale metal organic framework-based stimulus response systems for drug delivery, including pH, magnetics, light, ion, temperature, and other stimuli, as well as multiple stimulus-responsive drug delivery systems. Finally, we discuss the challenges and future development directions of nanoscale metal organic framework-based controlled drug release.

16.
Med Sci Monit ; 26: e924946, 2020 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-32918441

RESUMO

BACKGROUND The have been few reports on use of ERAS in LC combined with LCBDE to promote postoperative recovery of patients. Therefore, the purpose of this cohort study was to explore the use of ERAS in patients who underwent LC combined with LCBDE. MATERIAL AND METHODS We collected clinical data of 445 patients who underwent elective laparoscopic cholecystectomy combined with laparoscopic common bile duct exploration from January 2015 to February 2019 in our hospital and divided the patients into an E-LC group and an LC group. The stress response index, postoperative complication rate, and postoperative rehabilitation effect of the 2 groups were compared and analyzed. RESULTS The WBC count and CRP levels in the E-LC group were significantly lower than those of the LC group 1 day after surgery (p<0.05). In terms of the postoperative complications, the incidence of nausea, incisional pain, and vomiting in the E-LC group were lower than in the LC group, and the differences were statistically significant (p<0.05). In terms of the postoperative rehabilitation efficacy, flatus time and length of hospital stay after surgery in the E-LC group were significantly shorter than those in the LC group (p<0.05). CONCLUSIONS Use of ERAS in the perioperative period in patients who underwent LC combined with LCBDE reduces the stress response and postoperative complications and accelerates postoperative rehabilitation.

17.
Vascular ; : 1708538120950876, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32921291

RESUMO

OBJECTIVES: Aortic dissection involving the ascending aorta and aortic arch is a serious condition. Treatment using traditional surgical methods has certain disadvantages. This study investigated the effectiveness of thoracic endovascular repair of aortic dissection using an external prefenestrated stent. METHODS: We present a series of aortic dissection cases involving the ascending aorta and aortic arch treated with an external prefenestrated stent. RESULTS: Postoperative follow-up of the patients showed that all stents were released at the proper position and that branch vessels were not occluded, and there were no instances of type I endoleak. One patient died suddenly one week after surgery; another experienced retrograde type A aortic dissection in the second week; and type I endoleak occurred in one patient in the first week, although this resolved within six months. No serious complications such as cerebrovascular events, acute spinal cord ischemia, and paraplegia occurred during the perioperative period. All patients had false lumen thrombosis in the ascending aorta and aortic arch. CONCLUSION: Prefenestrated stent grafting is a feasible treatment option for repairing an entry tear in the ascending aorta.

18.
Hum Pathol ; 105: 47-52, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32946879

RESUMO

Special AT-rich sequence-binding protein 2 (SATB2) is a sensitive and specific marker for tumors originating with the colon and appendix. It is now commonly used in surgical pathology, while working up carcinomas of unknown primary. We had anecdotally encountered occasional hepatocellular carcinomas (HCCs) that were SATB2 positive. Immunohistochemical expression of SATB2 in HCC has not yet been examined in detail. In this study, we evaluated SATB2 expression in 46 HCCs. Nineteen (41%) of 46 HCCs were positive for SATB2. SATB2 expression in HCCs was more commonly seen in poorly differentiated tumors (11 of 13 cases, 85%) than well and moderately differentiated tumors (8 of 33 cases, 24%), p value = 0.0001. No other statistically significant correlations were observed (p > 0.05). There were no other statistically significant correlations between SATB2 expression and age, gender, background liver disease, and cirrhosis (p > 0.05). Results of our study show that a significant subset (41%) of HCCs can be SATB2 positive. Awareness of this phenomenon is important as SATB2 expression in a liver tumor does not completely exclude a diagnosis of HCC.

19.
Dalton Trans ; 49(39): 13582-13587, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-32970055

RESUMO

A catalytically active conjugated microporous polymer (SP-CMP-Cu) was facilely constructed with condensation polymerization of salen-Cu (salen = N,N'-bis(3-tertbutyl-5-formylsalicylidene) ethylenediamine) and pyrrole. The as-synthesized SP-CMP-Cu was completely characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray (EDX) analysis. The morphological features of SP-CMP-Cu were revealed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). According to the N2 adsorption/desorption isotherm, the Brunauer-Emmett-Teller (BET) surface area of SP-CMP-Cu was calculated to be 252 m2 g-1 with a total pore volume of 0.178 cm3 g-1. SP-CMP-Cu exhibited an outstanding catalytic performance for the Henry reaction in aqueous solutions with excellent conversion and good selectivity. Moreover, SP-CMP-Cu can be reused for up to five consecutive runs without any significant loss in its catalytic efficiency.

20.
Waste Manag ; 118: 27-35, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32882539

RESUMO

The formation of dibenzofuran (DF), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and environmentally persistent free radicals (EPFRs) from 1,2,3-trichlorobenzene (1,2,3-TrCBz) over metal oxide / silica surface were investigated using a tubular furnace. PCDD/Fs increased exponentially from 250 to 550 °C over copper oxide / silica surface and PCDD/Fs had the maximum growth from 400 to 450 °C. The ratio of PCDD / PCDF was much less than 1, especially when the temperature raised from 450 to 550 °C. Pentachlorianated dibenzo-p-furan (PeCDF) dominated among the homologues, which contributed 45-61% to the total PCDD/Fs. Two peaks of the yield of DF occurred at 400 °C and 500 °C respectively. Furthermore, the oxygen contents have different effects for PCDD and PCDF formation, and low oxygen could promote PCDD production, especially for tetrachlorinated dibenzo-p-dioxin (TCDD). More PCDF were formed on the oxygen rich condition, indicating that the oxygen promoted the chlorination of DF. Iron oxides are better than copper oxides to catalyze the formation of PCDD/Fs from 1,2,3-TrCBzs at 350 °C, especially for PCDF. The major EPFRs on the catalysts were formed with g values in the range of 2.0040 to 2.0049, which were phenoxy radicals and semiquinone occurred with higher g value of 2.0075 when the temperature increased to 550 °C, and more EPFRs were produced with the temperature increasing. The addition of iron oxides reduced the spins concentrations of oxygen-centered radicals but increase the spins concentrations of signals with lower g values. The different possible formation pathways of PCDD and PCDF from 1,2,3-TrCBz over metal oxide surface were also proposed.


Assuntos
Dibenzodioxinas Policloradas , Benzofuranos , Clorobenzenos , Dibenzofuranos , Dibenzofuranos Policlorados , Radicais Livres , Óxidos , Dióxido de Silício
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA