Search

The clinical significance of FLAIR vascular hyperintensity (FVH), a marker of collateral circulation in ischaemic stroke, remains controversial. We hypothesised that the association between FVH and outcomes varies with the severity of leukoaraiosis (LA), another marker of collaterals, and that their combined significance may vary with time. We included 459 consecutive patients with middle cerebral artery (MCA) stroke. Proximal and distal FVHs were distinguished based on location. LA was divided into two grades, according to Fazekas scores of 0–2 and 3–6. Symptom-to-MRI time was divided into two categories: ≤ 14 days and ≥ 15 days. We found no difference in FVH proportion according to LA grade. Multivariate analysis revealed that LA and FVH status were independently associated with unfavourable outcomes (modified Rankin scale ≥ 2) in patients with symptom-to-MRI times ≤ 14 days (P = 0.008), but not in those with symptom-to-MRI times ≥15 days (P = 0.61). In the group with symptom-to-MRI times ≤14 days, patients with LA 3–6 and FVH(+) (OR, 3.044; 95% CI, 1.116–8.305) were more likely to have unfavourable clinical outcomes compared with patients with LA 0–2 and FVH(+) but not compared with those with LA 0–2 and FVH(−) or LA 3–6 and FVH(−). In addition, FVH location did not influence the relationship between FVH and outcomes. The association between FVH and outcomes was influenced by the degree of LA in the acute but not in the subacute and chronic stages of MCA infarction. FVH predicts clinical outcomes independently only in those with more extensive LA.

Two-dimensional (2D) layered zeolites are new forms of 3D zeolite frameworks. They can be pillared to form more open porous structures with increased access for reactants that are too big for the micropores of zeolites. The current pillaring procedure, however, requires intercalation of pillaring precursors by dispersing 2D zeolite in an alkoxide liquid and hydrolizing entrapped alkoxide to form inorganic oxide pillars in an aqueous alkaline solution. Both steps use excess solvents, generate significant waste, and require multiple synthesis and separation steps. Here we report a vapor-phase pillarization (VPP) process to produce pillared zeolites from 2D layered zeolite structures. The VPP process has ∼100% efficiency of alkoxide usage in the intercalation step, requires less (and, in some cases, zero) water addition in the hydrolysis step, does not require separation for product recovery, and generates no liquid waste. Furthermore, synthesis of pillared zeolites via the VPP process can be accomplished within a single apparatus with one-time operation. The pillared zeolite prepared by the VPP method preserved the zeolitic layered structure as well as acidity and showed enhancement in catalytic alkylation of mesitylene with benzyl alcohol compared to 2D layered zeolite without pillarization treatment.

Background The incidence of ischemic stroke increases in winter. This study aimed to explore the effect of winter temperatures on the risk factors, etiology, coagulation, and degree of neurological impairment in patients with ischemic stroke using temperature and rainfall data from the Guangzhou Meteorological Bureau during the winter months of December, January, and February. Material/Methods We divided 112 patients with ischemic stroke into low-temperature and non-low-temperature groups. The low-temperature group experienced an average daily winter temperature of 13°C in the 14 days before hospital admission and an average daily temperature of >13°C on admission. Neurological deficits were scored and monitored using the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS) for disability in stroke. Blood pressure and coagulation indices of prothrombin time (PT) and thromboplastin time (TT) were recorded. Results Compared with the non-low-temperature group, the low-temperature group showed a significantly increased proportion of patients with hypertension and large artery atherosclerotic stroke, more prolonged PT, and higher NIHSS scores. However, TT was reduced in the low-temperature group (P

Hierarchical SAPO-34 zeolites with a special nanosheet-assembled morphology were hydrothermally synthesized under dynamic condition by using the commercial quaternary ammonium-type organosilane surfactant [3-(trimethoxysilyl) propyl] octadecyldimethyl-ammonium chloride (TPOAC) for the mesoscopic aggregation and tetraethylammonium hydroxide as the micropore structure-directing agent. The growth evolution during the crystallization process and governing factors including TPOAC content and dynamic hydrothermal condition in the synthesis were discussed in detail, and the possible nucleation and growth process were proposed as well. With a systematic structure characterization by XRD, FTIR, N2 adsorption–desorption, ICP, SEM, TEM, NH3-TPD and pyridine-adsorbed IR measurements, the nanosheet-assembled SAPO-34 (NA-SP34) prepared under the optimized synthesis condition presented the pure phase of CHA framework, high degree of crystallinity, interconnected hierarchical meso-/microporosity and relatively weak acidity comparing with the conventional microporous SAPO-34 (CM-SP34) with micron size and the nanosheet-like SAPO-34 (NL-SP34) synthesized in the absence of TPOAC. Moreover, the catalytic performances evaluated by the methanol-to-olefin reaction indicated that the optimal NA-SP34 catalyst presented remarkable improvements of not only much longer catalytic lifetime (300 min) and slower coke formation rate (0.24 mg g−1 min−1) but also higher ethylene and propylene selectivity (81.93%) comparing with those (95 min, 0.55 mg g−1 min−1 and 80.75%, respectively) of CM-SP34, which can be attributed to the integrated balance of well-remained microporosity, considerable mesoporosity and suitable weak acidity.

The pillared MWW (PMWW or MCM-36) and pillared MFI (PMFI) are two prominent representatives of meso-/microporous lamellar zeolites, which are made by pillaring of layered MCM-22(P) and multilamellar MFI precursors, respectively. They both consist of a 10-membered ring sinusoidal micropore channel within each zeolitic layer and mesopore voids created by pillars between two adjacent zeolitic layers. Although catalytic activities of PMWW and PMFI have been compared, identification of mesopore differences between these two pillared lamellar zeolites has not been attempted. In this work, we report the differences in mesopore characteristics between PMWW and PMFI zeolites probed by atomic layer deposition (ALD) of titania (ALD-TiO2) species and a combination of structural, textural, composition and catalytic property analyses of the samples before and after ALD treatment, respectively. The results suggest PMFI has cylindrical mesopores with uniform sizes from pore entrance to main body, while PMWW has ink-bottle mesopores with the neck size much smaller than pore body. The communication between micropore and mesopore in PMFI is direct, but no communication exists in PMWW zeolites. The ALD-TiO2 process considerably modified external surface composition of PMFI and PMWW zeolites, which consequently led to a new application of the pillared lamellar zeolite materials, i.e., photo-catalytically active meso-/microporous zeolites for environmental remedy reactions.

Although the use of sorafenib appears to increase the survival rate of renal cell carcinoma (RCC) patients, there is also a proportion of patients who exhibit a poor primary response to sorafenib treatment. Therefore, it is critical to elucidate the mechanisms underlying sorafenib resistance and find representative biomarkers for sorafenib treatment in RCC patients. Herein, we identified that a long noncoding RNA GAS5 was downregulated in sorafenib nonresponsive RCCs. GAS5 overexpression conferred sorafenib sensitive to nonresponsive RCC cells, whereas knockdown of GAS5 promoted responsive RCC cells resistant to sorafenib treatment in vitro and in vivo. Mechanistically, GAS5 functioned as competing endogenous RNA to repress miR-21, which controlled its down-stream target SOX5. We proposed that GAS5 was responsible for sorafenib resistance in RCC cells and GAS5 exerted its function through the miR-21/ SOX5 axis. Our findings suggested that GAS5 downregulation may be a new marker of poor response to sorafenib and GAS5 could be a potential therapeutic target for sorafenib treatment in RCC.

The hierarchical layered-bulky ZSM-5 (LBZ5) hybrid composites with a core–shell structure were synthesized by epitaxial growth of layered ZSM-5 nanosheets over bulky ZSM-5 crystals. The systematic balance of zeolitic microporosity and interlayered mesoporosity was achieved by elaborate regulation of the ratio between layered phase and bulky phase, resulting in a series of layered-bulky ZSM-5 hybrid composites with the controllable thickness of the layered shell ranging from 98 to 307 nm. The evaluation of catalytic performance in the methanol-to-propylene (MTP) reaction indicated the LBZ5 materials to be candidated catalysts for the MTP process with prolonged catalytic lifetime, superior coke toleration, and enhanced propylene selectivity compared with the parent bulky ZSM-5 (BZ5) and layered ZSM-5 (LZ5) due to their well-retained zeolitic framework, hierarchical meso-/microporosity by the layered-bulky composite structure, and appropriate strong acidity.

OBJECTIVES To summarize the clinical features of thymomatous myasthenia gravis (T-MG), examine the association between MG and thymoma, and identify the related factors or predictors for long-term prognosis of T-MG. METHODS A retrospective, observational study was conducted on 100 patients with T-MG and 96 patients with non-T-MG (NT-MG) between January 1, 2009 and December 31, 2019. The baseline characteristics were recorded for each patient. Logistic regression was used to measure the association between all clinical variables and T-MG prognosis. RESULTS Between the T-MG and NT-MG groups, age at onset (45.66 ± 11.53 years vs 39.06 ± 14.39 years); age >40 years (72.0% vs. 40.6%); AChR-Ab positive rate (100.0% vs. 83.3%); Myasthenia Gravis Foundation of America (MGFA) classification at the worst condition (≥grade III, 61.0% vs. 33.0%); thyroid dysfunction (7.0% vs. 20.8%); and outcome (complete stable remission + pharmacologic remission + improvement, 74.0% vs. 93.7%) were statistically significant (P

Gas-liquid separation technology under microgravity is the basis for various gas and liquid treatments on a manned spacecraft, which has a wide range of applications in Environmental Control and Life Support System. Dynamic gas-liquid separator is commonly used for the separation of gas-liquid two-phase flow, which has two essential performance parameters called liquid outlet pressure and separating efficiency. Predicting these two parameters accurately under a specific structure has guiding significance for design and application of the dynamic gas-liquid separator. In this study, CFD simulations were conducted using the Volume of Fluid (VOF) model at steady state conditions. In addition, experiments were designed to verify the accuracy of numerical results. Finally, the performance of the separator under microgravity was predicted. It is showed that the simulation method can be utilized to determine the transport performance of dynamic gas-liquid separator, which has significant value in design and optimization.

A space station that operates under microgravity conditions is a closed environment where a reasonable airflow distribution is required to eliminate body heat dissipation, remove contaminants and thus keep the crew comfortable. However, design of a reasonable airflow distribution has remained challenging. In this study, a computational fluid dynamics (CFD) methods with various turbulence models were used to investigate the airflow distribution inside a space station under microgravity conditions. To compare the performance of different models, the shrinkable ratio method was used to set up a mockup station to eliminate the influence of gravity-induced natural convection. The air velocity distribution in the narrow scale model was measured using particle image velocimetry (PIV). Results showed that the performance of the standard k-e turbulence model was better than the renormalized group (RNG) k-e turbulence model. The air distribution was optimized by changing the angle of the air supply outlet, suggesting that a three-dimensional air supply can provide better thermal comfort and higher air quality.

The hierarchical ZSM-5 zeolites with interconnected meso-/microporosity have been successfully synthesized by using the commercial organosilane surfactant TPOAC as the mesopore structure-directing ...

Two types of BEA/MFI zeolite nanocomposites with hierarchical meso-/microporisty structures were synthesized via two different procedures based on the confined space synthesis strategy. By using the three-dimensionally ordered mesoporous (3DOm) carbon as the confined space provider, BEA and MFI zeolites were successively grown within the 3DOm carbon under an alternated hydrothermal treatment condition, resulting in the product zeolite nanocomposite with an ordered assembly structure constituted by zeolite nanoparticles of two dissimilar frameworks (BEA and MFI) and a three-dimensional highly ordered mesoporosity replicated from the 3DOm carbon template. Another synthesis strategy was by overgrown of MFI crystals over BEA zeolite with a three-dimensionally ordered mesoporous-inprinted structure (3DOm-i BEA), and the obtained BEA/MFI zeolite nanocomposites revealed a hierarchical meso-/microporisty and various intergrowth morphologies.

Hierarchical SAPO-34 zeolites with three-dimensionally ordered mesoporous-imprinted structure (3DOm-i SAPO-34) were first confined synthesized within three-dimensionally ordered mesoporous carbons by multiple hydrothermal (MHT) treatments. With perfect structure replication, the obtained 3DOm-i SAPO-34 zeolite particles exhibited unique ordered structures consisting of primary spherical elements of sizes determined by mesopore cages of the corresponding carbon templates, and the sizes of mesopores constituted by the adjacent spherical elements can be precisely tuned from 5.5 to 13.0 nm by varying the 3DOm carbon. The as-synthesized hierarchical 3DOm-i SAPO-34 catalysts showed superior catalytic performance in the MTO reaction with prolonged catalytic lifetime and significant improvement of selectivity for light olefins (ethylene and propylene) compared to the conventional microporous SAPO-34.

Wernicke encephalopathy (WE) is characterized by eye signs, cerebellar dysfunction, and confusion. Epileptic seizures are rare in nonalcoholic WE. We reviewed the clinical, laboratory, radiological, and prognostic characteristics of nonalcoholic WE accompanied by epileptic seizures. We reported 1 case and searched similar cases using PubMed, WoK, Ovid, and Embase. WE was diagnosed according to dietary deficiencies, clinical symptoms and brain magnetic resonance imaging (MRI). We reviewed 13 patients (median age, 27 years; 5 men) with clear histories of thiamine deficiency and symptoms of typical WE. The type of epileptic seizures reported in the 13 cases reviewed was generically reported as seizures or convulsions in 4 patients; 7 patients had generalized tonic-clonic seizures, 1 partial seizure, and 1 generalized convulsive status epileptics. Two patients had epileptic seizures as the first symptom of WE. Laboratory tests mainly indicated metabolic acidosis and electrolyte disturbances. Electroencephalography may present as normal patterns, increased slow waves or epileptic discharge. Six patients had cortical lesions on brain MRI. These lesions were usually diffuse and band-like, and sometimes involved all lobes either symmetrically or asymmetrically, with the frontal lobe as the most susceptible area. All cortical lesions were accompanied by non-cortical lesions typical of WE. Brain MRI abnormalities, after thiamine treatment, mostly disappeared on follow-up MRIs. The patients had good prognoses. Only 1 patient had repeated seizures, and there were no comas or deaths. Patients with nonalcoholic WE accompanied by seizures are young and generally have good prognoses. Most patients experienced generalized convulsive seizures, which may have been related to abnormal cerebral cortical metabolism due to subacute thiamine deficiency.

BACKGROUND AND PURPOSE: FLAIR vascular hyperintensity has been recognized as a marker of collaterals in ischemic stroke, but the impact on outcome is still controversial. We hypothesized that the association between FLAIR vascular hyperintensity and outcome varies with time. MATERIALS AND METHODS: We included 459 consecutive patients with middle cerebral artery stroke and divided them into 3 groups by symptom-to-MR imaging time (group 1, ≤7 days; group 2, 8–14 days; group 3, ≥15 days). The FLAIR vascular hyperintensity score, ranging from 0 to 3 points, was based on territory distributions of different MCA segments. The associations between FLAIR vascular hyperintensity and outcome with time were analyzed qualitatively and quantitatively. RESULTS: No patients underwent MR imaging within 6 hours of onset. The proportion of FLAIR vascular hyperintensity (+) and severe stenosis or occlusion of MCA was not significantly dependent on time. In groups 1 and 2, FLAIR vascular hyperintensity (+) was significantly associated with larger lesions, the prevalence of flow injury, and unfavorable outcome (mRS ≥ 2). There were no such associations in group 3. Multiple logistic regressions demonstrated that FLAIR vascular hyperintensity (+) was an independent risk factor for unfavorable outcome in group 2. Infarction volume tended to increase with the increase of the distal FLAIR vascular hyperintensity score in groups 1 and 2, while declining in group 3. CONCLUSIONS: FLAIR vascular hyperintensity is associated with unfavorable outcome within 6 hours to 14 days of onset, while the wider distribution of distal FLAIR vascular hyperintensity may be favorable beyond 14 days of onset in MCA infarction. Symptom-to-MR imaging time should be considered when assessing the prognostic value of FLAIR vascular hyperintensity.

Although the use of sorafenib appears to increase the survival rate of renal cell carcinoma (RCC) patients, there is also a proportion of patients who exhibit a poor primary response to sorafenib treatment. Therefore, it is critical to elucidate the mechanisms underlying sorafenib resistance and find representative biomarkers for sorafenib treatment in RCC patients. Herein, we identified that a long noncoding RNA GAS5 was downregulated in sorafenib nonresponsive RCCs. GAS5 overexpression conferred sorafenib sensitive to nonresponsive RCC cells, whereas knockdown of GAS5 promoted responsive RCC cells resistant to sorafenib treatment in vitro and in vivo. Mechanistically, GAS5 functioned as competing endogenous RNA to repress miR-21, which controlled its down-stream target SOX5. We proposed that GAS5 was responsible for sorafenib resistance in RCC cells and GAS5 exerted its function through the miR-21/ SOX5 axis. Our findings suggested that GAS5 downregulation may be a new marker of poor response to sorafenib and GAS5 could be a potential therapeutic target for sorafenib treatment in RCC.

Background Cortical vein thrombosis (CVT) receives little attention in adult patients with cerebral venous sinus thrombosis (CVST). This study aimed to investigate the clinical and radiological features of adult CVST patients with concomitant CVT. Methods From May 2009 to May 2016, we recruited 44 adult CVST patients (diagnosed within 1 month of onset; 33.8 ± 14.0 years of age, 28 males). CVT was primarily confirmed using computed tomography venography and magnetic resonance imaging sequence of contrast enhanced three dimensions magnetization prepared rapid acquisition with gradient echo. Patients with concomitant CVT were divided into the CVT group; otherwise, the patients were placed into the non-CVT group. The clinico-radiological characteristics were compared between the two groups. Results The CVT group included 27 patients (61.4%), and the non-CVT group included 17 patients (38.6%). Seizure (63.0% versus 11.8%), focal neurological deficits (44.4% versus 5.9%), and consciousness disorders (33.3% versus 0) occurred more frequently in the patients in the CVT group than in those of the non-CVT group (P

The use of CTV, MRV, and CE-3D-MPRAGE in two groups. Table S1 showed that the rates of CTV, MRV, and CE-3D-MPRAGE utilization in CVT group were 29.6%, 85.2% and 85.2% respectively, while the rates in non-CVT group were 23.5%, 100% and 100% respectively. Table S2. Positive rate of CVT of different neuroimaging tests in the patients of CVT group respectively. Table S2 demonstrated that positive rate of CTV was 75.0% and lower than CE-3D-MPRAGE (95.7%). (DOCX 16 kb)

This article was migrated. The article was not marked as recommended. Objective：The aim of this study was to identify the disciplines that strongly correlated with neurology, and to compare the differences between neurology and other disciplines in targeted integration. Method: Scores of 18 disciplines (six clinical disciplines, seven basic disciplines, and five social science/humanities disciplines) and college entrance examinations of 275 eight-year program medical students from Sun Yat-Sen University were collected. Correlation between any two subject scores were determined. Results: Student scores in neurology had significant correlation with the scores of four clinical subjects, five basic subjects, and one social science/ humanities subject. Internal medicine scores showed significant correlation with the scores of three clinical subjects and two basic subjects. Scores from obstetrics and gynecology, pediatrics and psychiatry significantly correlated with one to three clinical subjects scores. No significant correlation was found between surgery scores and other subjects. With the exception of medical statistics, there was no significant correlation between scores from social science/humanities subjects and scores from either clinical or basic subjects. No subject scores significantly correlated with the college entrance examination scores. Conclusion: Neurology is associated with more clinical and basic disciplines than other subjects. Neurological education should involve a targeted integration with other closely related disciplines.

In computer controlled optical surfacing (CCOS), edge effect is a problem that needs to be solved as soon as immediately. When the polishing tool moves along the edge of the workpiece, the theoretical removal function model is not suitable for the machining practice. The pressure distribution is studied when the polishing tool goes beyond the border of the workpiece. The pressure distribution along the radius of the workpiece is presented and the calculation formula is given. The character of the pressure distribution is analyzed. On the basis of the analysis of the pressure distribution and the Preston hypothesis the amendment model of the removal function is established. The calculation formula of the amendment model is given and numeric analysis of the amendment model is processed. Using Matlab, the 3D simulation result of the amendment model is obtained. The removal profiles along X-axis and Y-axis are plotted. The characteristics of the amendment model are analyzed. Comparing the experiment results with the simulation results verifies the accuracy of the amendment model. Typical phenomena in experiments are analyzed and appropriate removal performance is illustrated. Our model correctly predicts that a greater amount of material is removed from the edge of the workpiece.

The effects of annealing temperature (600°C, 625°C, 650°C, 680°C) and aluminum content (1.5%, 2.0%, 2.5%) on the microstructures and mechanical properties of complex aluminum-brass were investigated. The results show that with the increase of Al content, the grains of Al-brass become finer, and the tensile strength increases, while the elongation decreases. The tensile strength and the elongation of Al-brass with 1.5% Al are ∼430MPa and 36%, respectively. However, the tensile strength and the elongation of Al-brass with 2.5% Al are 470MPa and 24%, respectively. The recrystallization temperature enhances with the increase of Al content. The recrystallization temperature of cold-rolled plate with 1.5% Al is about 625°C, while that of plate with 2.5% Al is about 680°C.