Spinal Cord Diffuse Midline Gliomas With H3 K27m-Mutant: Clinicopathological Features and Prognosis.

BACKGROUND: "Diffuse midline glioma, H3 K27M-mutant" (DMG) mainly arises within the pontine, thalamic, and spinal cord regions. Because of the rarity of spinal cord gliomas, the general knowledge surrounding DMGs is mainly based on pontine and thalamic gliomas, whereas tumor location tends to influence the clinicopathological features and prognosis. OBJECTIVE: To determine the clinicopathological characteristics and molecular profiles of DMGs located in the spinal cord. METHODS: The clinical and molecular pathologic features and prognosis were comprehensively analyzed in a series of 44 patients with spinal cord DMGs. RESULTS: The median age was 36 yr, and 88.7% of patients (39/44) were adults (≥18 yr). Histopathologically, malignant grades included grade II (16 cases), grade III (20 cases), and grade IV (8 cases). Compared with patients with histological grade IV, patients with lower histological grade (grade II/III) were older (37 vs 24 yr, P = .020) and were associated with longer overall survival (24.1 vs 8.6 mo, P = .007). All 30 tested tumors were isocitrate dehydrogenase (IDH) wild type, and 96% of cases (22/23) presented with unmethylated O6-methylguanine-DNA methyltransferase. Univariate and multivariate analyses showed that histological grade and presurgery McCormick Scale scores were independent prognostic factors for overall survival, whereas extensive surgical resection and chemoradiotherapy were not significantly associated with improved survival. The most frequent anatomic locations were the cervical enlargement (C4-T1, n = 16) and conus medullaris (T12-L1, n = 13), which exhibited distinctive clinical characteristics and molecular features. CONCLUSION: The findings provide guidelines for the evidence-based practice of the specialized management of spinal cord DMGs.

Clinicopathological characteristics and survival of spinal cord astrocytomas.

BACKGROUND: Due to their rarity, the clinicopathological characteristics and prognostic factors of spinal cord gliomas are still unclear. Here, we aimed to clarify these issues in a cohort of 108 spinal cord astrocytomas. METHODS: We characterized the clinicopathological characteristics, including 2016 World Health Organization (WHO) grade, age, sex, location, segment length, resection, pre- and postsurgery, Modified McCormick Scale (MMS), radio- and chemotherapy, and Ki-67 and H3 K27M mutations, in 108 spinal cord astrocytomas through heatmaps. The Cox regression analysis and Kaplan-Meier curves were used to study the prognostic value of these clinicopathological features. RESULTS: There are a total 38 H3 K27M-mutant tumors, including 31 cases with histological grade II/III tumors. The age of low-grade astrocytoma patients (WHO grade I/II, n = 54) was significantly younger (27.0 vs 35.5 years, P = .001) than those with high-grade tumors (WHO grade III/IV, n = 54). All patients underwent surgical resection with neurophysiological monitoring, and the surgery did not result in significant changes in MMS. The presurgery MMS was associated with overall survival in the high-grade subgroup (P = .008) but not in the low-grade subgroup (P = .312). While, the high content of resection improved the survival of only patients with low-grade astrocytomas (P = .016) but not those with high-grade astrocytomas (P = .475). Both the low-grade and high-grade astrocytomas had no obvious benefit from neither adjuvant chemotherapy nor radiotherapy (all P > .05). CONCLUSIONS: We characterized the clinicopathological characteristics and their prognostic values in 108 spinal cord astrocytomas, which could help with evidence-based management of spinal cord astrocytomas.

[Effect of Relative Humidity on Particulate Matter Concentration and Visibility During Winter in Chengdu].

The effect of relative humidity (RH) on particulate matter concentrations and atmosphere visibility were investigated using the continuous on-line observed data of Chengdu city during December 2015, including RH, visibility, the concentrations of particulate matters (PM10, PM2.5 and PM1) and gaseous pollutants (SO2 and NO2), and the concentrations of SO42- and NO3- in PM2.5. The results showed that the haze process occurred because of the synergistic effects of higher particulate matter concentrations and RH, leading to the reduction of visibility. The average ratio of PM2.5 to PM10 was 64% and it significantly increased with the increase of RH during observation period, which indicated that the pollution of fine particles during winter in Chengdu was serious, and high RH aggravated the pollution caused by fine particles.Visibility decreased exponentially with the increase of particulate matter concentrations. When RH was higher, visibility was lower at the same concentrations of particulate matter.RH had a strong effect on visibility at lower particle concentrations, while the effect of RH on the visibility decreased, and atmospheric extinction was controlled by PM2.5 concentrations at higher particle concentrations. With RH increasing from less than 40% to more than 70%, the average sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) increased from 0.27 and 0.11 to 0.40 and 0.19, respectively, indicating that higher RH significantly promoted the formation of secondary sulfate and nitrate. Secondary sulfate and nitrate separately or coordinatively influenced the air quality.

[Flue gas desulfurization by a novel biomass activated carbon].

A novel biomass columnar activated carbon was prepared from walnut shell and pyrolusite was added as a catalyst. The activated carbon prepared was used for flue gas desulphurization in a fixed-bed reactor with 16 g of activated carbon. The impact of operating parameters such as SO2 inlet concentration, space velocity, bed temperature, moisture content and O2 concentration on the desulfurization efficiency of activated carbon was investigated. The results showed that both the breakthrough sulfur capacity and breakthrough time of activated carbon decreased with the increase of SO2 inlet concentration within the range of 0.1% -0.3%. The breakthrough sulfur capacity deceased with the increase of space velocity, with optimal space velocity of 600 h(-1). The optimal bed temperature was 80 degrees C, and the desulfurization efficiency can be reduced if the temperature continue to increase. The presence of moisture and oxygen greatly promoted the adsorption of SO2 onto the activated carbon. The best moisture content was 10%. When the oxygen concentrations were between 10% and 13%, the desulfurization performance of activated carbon was the highest. Under the optimal operating conditions, the sulfur capacity of activated carbon was 252 mg x g(-1), and the breakthrough time was up to 26 h when the SO2 inlet concentration was 0.2%.

Simultaneous absorption of NOx and SO2 from flue gas with pyrolusite slurry combined with gas-phase oxidation of NO using ozone.

NO was oxidized into NO(2) first by injecting ozone into flue gas stream, and then NO(2) was absorbed from flue gas simultaneously with SO(2) by pyrolusite slurry. Reaction mechanism and products during the absorption process were discussed in the followings. Effects of concentrations of injected ozone, inlet NO, pyrolusite and reaction temperature on NO(x)/SO(2) removal efficiency and Mn extraction rate were also investigated. The results showed that ozone could oxidize NO to NO(2) with selectivity and high efficiency, furthermore, MnO(2) in pyrolusite slurry could oxidize SO(2) and NO(2) into MnSO(4) and Mn(NO(3))(2) in liquid phase, respectively. Temperature and concentrations of injected ozone and inlet NO had little impact on both SO(2) removal efficiency and Mn extraction rate. Specifically, Mn extraction rate remained steady at around 85% when SO(2) removal efficiency dropped to 90%. NO(x) removal efficiency increased with the increasing of ozone concentration, inlet NO concentration and pyrolusite concentration, however, it remained stable when reaction temperature increased from 20°C to 40°C and decreased when the flue gas temperature exceeded 40°C. NO(x) removal efficiency reached 82% when inlet NO at 750 ppm, injected ozone at 900 ppm, concentration of pyrolusite at 500 g/L and temperature at 25°C.

Rapid formation of hydrogen-producing granules in an anaerobic continuous stirred tank reactor induced by acid incubation.

A novel approach to rapidly initiate granulation of hydrogen-producing sludge was developed in an anaerobic continuous stirred tank reactor at 37 degrees C. To induce microbial granulation, the acclimated culture was subject to an acid incubation for 24 h by shifting the culture pH from 5.5 to 2.0. The culture was resumed to pH 5.5 after the incubation and the reactor was operated at hydraulic retention times (HRTs) of 12, 6, 2, 1, and 0.5 h in sequence. Microbial aggregation took place immediately with the initiation of acid incubation and granules were developed at 114 h. No granule was observed in the absence of acid incubation in the control test. Changing the culture pH resulted in improvement in surface physicochemical properties of the culture favoring microbial granulation. The zeta potential increased from -11.6 to -3.5 mV, hydrophobicity in terms of contact angle improved from 31 degrees to 43 degrees and extracellular proteins/polysaccharides ratio increased from 0.2 to 0.5-0.8. Formation of granular sludge facilitated biomass retention of up to 32.2 g-VSS/L and enhanced hydrogen production. The hydrogen production rate and hydrogen yield increased with the reduction in HRT at an influent glucose concentration of 10 g/L once steady granular sludge layer was formed, achieving the respective peaks of 3.20 L/L x h and 1.81 mol-H(2)/mol-glucose at 0.5 h HRT. The experimental results suggested that acid incubation was able to initiate the rapid formation of hydrogen-producing granules by regulating the surface characteristics of microbial aggregates in a well-mixed reactor, which enhanced the hydrogen production.

[Aqueous oxidation of SO2 with microbial method].

The desulfurizations in dilute sulfuric acid solution, acidic ferric solution, acidic ferrous solution, microbial solution (Thiobacillus ferrooridans) and microbial culture medium solution were conducted to discuss biodesulfurization mechanism. The effect of Fe3+ concentration, Fe2+ concentration, SO2 concentration and temperature on biodesulfurization was examined on SO4(2-) concentration in the solution. Biodesulfurization has two ways: direct oxidation and indirect oxidation. In direct oxidation, Thiobacillus ferrooxridans oxidize S(IV) to S(VI). In indirect oxidation, Thiobacillus ferrooxidans can fast transform Fe2+ to Fe3+ in acidic conditions and then increase aqueous catalytic oxidation capacity of Fe3+ on SO2. It shows that indirect oxidation is the dominant way in biodesulfurization process. The desulfurization efficiency increase with concentration of Fe3+ or Fe2+ in the range of 0-1.2 g/L. Thiobacillus ferrooxidans enforce oxidation of SO2 in Fe3+ /Fe2+ system. The removal of SO2 decrease as concentration of SO2 increase, however, concentrations of SO4(2-) in the solution do not vary much in different inlet concentrations of SO2. Temperature has important effect on biodesulfurization. The optimal operative temperature range is 30-40 degrees C.

A pilot-scale jet bubbling reactor for wet flue gas desulfurization with pyrolusite.

MnO2 in pyrolusite can react with SO2 in flue gas and obtain by-product MnSO4 x H2O. A pilot scale jet bubbling reactor was applied in this work. Different factors affecting both SO2 absorption efficiency and Mn2+ extraction rate have been investigated, these factors include temperature of inlet gas flue, ration of liquid/solid mass flow rate (L/S), pyrolusite grade, and SO2 concentration in the inlet flue gas. In the meantime, the procedure of purification of absorption liquid was also discussed. Experiment results indicated that the increase of temperature from 30 to 70 K caused the increase of SO2 absorption efficiency from 81.4% to 91.2%. And when SO2 concentration in the inlet flue gas increased from 500 to 3000 ppm, SO2 absorption efficiency and Mn2+ extraction rate decreased from 98.1% to 82.2% and from 82.8% to 61.7%, respectively. The content of MnO2 in pyrolusite had a neglectable effect on SO2 absorption efficiency. Low L/S was good for both removal of SO2 and Mn2+ extraction. The absorption liquid was filtrated and purified to remove Si, Mg, Ca, Fe, Al and heavy metals, last product MnSO4 x H2O was obtained which quality could reach China GB1622-86, the industry grade standards.