Research Updates on the Mechanism and Influencing Factors of the Photocatalytic Degradation of Perfluorooctanoic Acid (PFOA) in Water Environments.

Perfluorooctanoic acid is ubiquitous in water bodies and is detrimental to the health of organisms. Effectively removing perfluorooctanoic acid (PFOA), a persistent organic pollutant, has been a hot topic around the world. With traditional physical, chemical, and biological methods, it is difficult to effectively and completely remove PFOA, the costs are high, and it is easy to cause secondary pollution. There are difficulties in applying some technologies. Therefore, more efficient and green degradation technologies have been sought. Photochemical degradation has been shown to be a low-cost, efficient, and sustainable technique for PFOA removal from water. Photocatalytic degradation technology offers great potential and prospects for the efficient degradation of PFOA. Most studies on PFOA have been conducted under ideal laboratory conditions at concentrations that are higher than those detected in real wastewater. This paper summarizes the research status of the photo-oxidative degradation of PFOA, and it summarizes the mechanism and kinetics of PFOA degradation in different systems, as well as the influence of key factors on the photo-oxidative degradation and defluoridation process, such as system pH, photocatalyst concentration, etc. PFOA photodegradation technology's existing problems and future work directions are also presented. This review provides a useful reference for future research on PFOA pollution control technology.

Tissue damage detected by quantitative gradient echo MRI correlates with clinical progression in non-relapsing progressive MS.

BACKGROUND: Imaging biomarkers of progressive multiple sclerosis (MS) are needed. Quantitative gradient recalled echo (qGRE) magnetic resonance imaging (MRI) evaluates microstructural tissue damage in MS. OBJECTIVE: To evaluate qGRE-derived R2t* as an imaging biomarker of MS progression compared with atrophy and lesion burden. METHODS: Twenty-three non-relapsing progressive MS (PMS), 22 relapsing-remitting MS (RRMS), and 18 healthy control participants underwent standard MS physical and cognitive neurological assessments and imaging with qGRE, FLAIR, and MPRAGE at 3T. PMS subjects were tested clinically and imaged every 9 months over 45 months. Imaging measures included lesion burden, atrophy, and R2t* in cortical gray matter (GM), deep GM, and normal-appearing white matter (NAWM). Longitudinal analysis of clinical performance and imaging biomarkers in PMS subjects was conducted via linear models with subject as repeated, within-subject factor. Relationship between imaging biomarkers and clinical scores was assessed by Spearman rank correlation. RESULTS: R2t* reductions correlated with neurological impairment cross-sectionally and longitudinally. PMS patients with clinically defined disease progression (N = 13) showed faster decrease of R2t* in NAWM and deep GM compared with the clinically stable PMS group (N = 10). Importantly, tissue damage measured by R2t* outperformed lesion burden and atrophy as a biomarker of progression during the study period. CONCLUSION: qGRE-derived R2t* is a potential imaging biomarker of MS progression.

Curcumin Ameliorates Copper-Induced Neurotoxicity Through Inhibiting Oxidative Stress and Mitochondrial Apoptosis in SH-SY5Y Cells.

Impaired homeostasis of copper has been linked to different pathophysiological mechanisms in neurodegenerative diseases and oxidative injury has been proposed as the main mechanism. This study aims to use curcumin, a widely used antioxidative and anti-apoptotic agent, to exert the neuroprotective effect against copper in vitro and illuminate the underlying mechanism. The effect of curcumin was examined by using a cell counting kit-8 assay, flow cytometry, immunofluorescence, spectrophotometer, and western blot. Results revealed that after pretreatment with curcumin for 3 h, copper-induced toxicity and apoptosis show a significant decline. Further experiments showed that curcumin not only decreased the production of ROS and MDA but also increased the activities of the ROS scavenging enzymes SOD and CAT. Moreover, curcumin treatment alleviated the decrease in mitochondrial membrane potential and the nuclear translocation of cytochrome c induced by copper. The protein levels of pro-caspase 3, pro-caspase 9, and PARP1 were up-regulated and the Bax/Bcl-2 ratio was down-regulated in the presence of curcumin. Taken together, our study demonstrates that curcumin has neuroprotective properties against copper in SH-SY5Y cells and the potential mechanisms might be related to oxidative stress and mitochondrial apoptosis.

Single scan quantitative gradient recalled echo MRI for evaluation of tissue damage in lesions and normal appearing gray and white matter in multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a chronic disease affecting the human central nervous system (CNS) and leading to neurologic disability. Although conventional MRI techniques can readily detect focal white matter (WM) lesions, it remains challenging to quantify tissue damage in normal-appearing gray matter (GM) and WM. PURPOSE: To demonstrate that a new MRI biomarker, R2t*, can provide quantitative analysis of tissue damage across the brain in MS patients in a single scan. STUDY TYPE: Prospective. SUBJECTS: Forty-four MS patients and 19 healthy controls (HC). FIELD STRENGTH/SEQUENCE: 3T, quantitative gradient-recalled-echo (qGRE), Magnetization-prepared rapid gradient-echo, fluid-attenuated inversion recovery. ASSESSMENT: Severity of tissue damage was assessed by reduced R2t*. Tissue atrophy was assessed by cortical thickness and cervical spinal cord cross-sectional area (CSA). Multiple Sclerosis Functional Composite was used for clinical assessment. RESULTS: R2t* in cortical GM was more sensitive to MS damage than cortical atrophy. Using more than two standard deviations (SD) reduction versus age-matched HC as the cutoff, 48% of MS patients showed lower R2t*, versus only 9% with lower cortical thickness. Significant correlations between severities of tissue injury were identified among 1) upper cervical cord and several cortical regions, including motor cortex (P < 0.001), and 2) adjacent regions of GM and subcortical WM (P < 0.001). R2t*-defined tissue cellular damage in cortical GM was greater relative to adjacent WM. Reductions in cortical R2t* correlated with cognitive impairment (P < 0.01). Motor-related clinical signs correlated most with cervical cord CSA (P < 0.001). DATA CONCLUSION: Reductions in R2t* within cortical GM was more sensitive to tissue damage than atrophy, potentially allowing a reduced sample size in clinical trials. R2t* together with structural morphometry suggested topographic patterns of regions showing correlated tissue damage throughout the brain and the cervical spinal cord of MS patients. LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:487-498.

[Tissue distribution of galactosyl daphnoretin liposomes in rats].

To study the tissue distribution of galactosyl daphnoretin liposomes in rats. At the dose of 10 mg•kg⁻¹, daphnoretin solution, daphnoretin liposomes, and galactosyl daphnoretin liposomes were administered to healthy SD rats via tail vein injection. The blood and tissue of heart, liver, spleen, lung, kidney, stomach, small intestine, brain and thymus were collected at 5, 15, 30, 45, 60, 120, 240, 360 min after administration. The concentrations of daphnoretin in plasma and tissue samples were determined by HPLC. The results showed that galactosyl daphnoretin liposomes group had the highest concentration of daphnoretin in liver of unit weight at different time points; and at all of the time points, the target index DTI values of galactosyl daphnoretin liposomes to liver were greater than that of daphnoretin liposomes. Compared with daphnoretin solution, the AUC0-6 and Cmax of galactosyl daphnoretin liposomes in liver were 2.23, 5.22 times, respectively. This indicated that galactosyl daphnoretin liposomes can be concentrated at liver, with a significant liver targeting effect.

The speed control of PMLSM with discontinuous driving coils based on multi-loop DOB model.

A permanent magnet linear synchronous motor (PMLSM) with discontinuous driving coils potentially applied in the underground pipeline freight delivery system is introduced in this article. Firstly, the detailed structure of the PMLSM with discontinuous driving coils is designed and presented, and the dynamic models of the PMLSM during three different processes are developed. In addition, based on the proportional-integral (PI) and the adaptive disturbance observer (DOB), a multi-loop control strategy is designed for the PMLSM with discontinuous driving coils. The critical performances of PMLSM, such as the speed precision and anti-disturbance ability, are testified in the experiment, and the results validate that the multi-loop control model with adaptive DOB used in the PMLSM with discontinuous driving coils has better speed precision than the PI+PI model by suppressing the detent force.

Histology and transcriptomic analysis reveal the inflammation and affected pathways under 2-methylisoborneol (2-MIB) exposure on grass carp.

2-Methylisoborneol (2-MIB) is a common and widely distributed off-flavor compound in water. However, the toxic mechanisms of 2-MIB on aquatic organisms remain largely unexplored. In this study, grass carp larvae were exposed to different concentrations (0, 5, and 20 µg L-1) of 2-MIB for 96 h. The accumulation of 2-MIB in the dorsal muscle was measured. Histological analysis, ultrastructure observations, and transcriptomic sequencing were conducted on the liver tissues. The results showed that 2-MIB accumulated significantly in the fish muscle, with the accumulation increasing as the exposure concentration increased through gas chromatography-mass spectrometry (GC-MS) detection. Histological and ultrastructure observations indicated that 2-MIB caused concentration-dependent inflammatory infiltration and mitochondrial damage in the liver. Transcriptomic analysis revealed lipid metabolism disorders induced by exposure to 2-MIB in grass carp. Additionally, 5 µg L-1 2-MIB affected the neurodevelopment and cardiovascular system of grass carp larvae through extracellular matrix (ECM)-receptor interaction and focal adhesion pathway. Furthermore, several pathways related to the digestive system were significantly enriched, implying that 2-MIB may impact pancreatic secretion function, protein digestion and absorption processes. These findings provide new insights into the potential toxicological mechanisms of 2-MIB.

Acoustic velocity log numerical simulation and saturation estimation of gas hydrate reservoir in Shenhu area, South China Sea.

Gas hydrate model and free gas model are established, and two-phase theory (TPT) for numerical simulation of elastic wave velocity is adopted to investigate the unconsolidated deep-water sedimentary strata in Shenhu area, South China Sea. The relationships between compression wave (P wave) velocity and gas hydrate saturation, free gas saturation, and sediment porosity at site SH2 are studied, respectively, and gas hydrate saturation of research area is estimated by gas hydrate model. In depth of 50 to 245 m below seafloor (mbsf), as sediment porosity decreases, P wave velocity increases gradually; as gas hydrate saturation increases, P wave velocity increases gradually; as free gas saturation increases, P wave velocity decreases. This rule is almost consistent with the previous research result. In depth of 195 to 220 mbsf, the actual measurement of P wave velocity increases significantly relative to the P wave velocity of saturated water modeling, and this layer is determined to be rich in gas hydrate. The average value of gas hydrate saturation estimated from the TPT model is 23.2%, and the maximum saturation is 31.5%, which is basically in accordance with simplified three-phase equation (STPE), effective medium theory (EMT), resistivity log (Rt), and chloride anomaly method.

Preparation of aluminium-hydroxide-modified diatomite and its fluoride adsorption mechanism.

As the current excessive accumulation of fluoride (F-) in the environment can be hazardous to human health, it is essential to remove fluoride from wastewater. In this study, diatomite (DA) was used as a raw material and modified using aluminum hydroxide (Al-DA) for use in the adsorption of F- from water bodies. SEM, EDS, XRD, FTIR, and Zeta potential characterization analyses were carried out; adsorption tests and kinetic fitting were performed, and the effects of pH, dosing quantity, and presence of interfering ions on the adsorption of F- by the materials were investigated. The results show that the Freundlich model effectively describes the adsorption process of F- on DA, which therefore involves adsorption-complexation interactions; however, the Langmuir model effectively describes the adsorption process of F- on Al-DA, corresponding to unimolecular layer adsorption mainly via ion-exchange interactions, that is, adsorption is dominated by chemisorption. Aluminum hydroxide was shown to be the main species involved in F- adsorption. The efficiency of F- removal by DA and Al-DA was over 91% and 97% for 2 h, and the adsorption kinetics were effectively fit by the quasi-secondary model, suggesting that chemical interactions between the absorbents and F- control the adsorption process. The adsorption of F- was highly dependent on the pH of the system, and the maximum adsorption performance was obtained at pH 6 and 4. The optimal dosage of DA and Al-DA was 4 g/L. Even in the presence of interfering ions, the removal of F- on Al-DA reached 89%, showing good selectivity. XRD and FTIR studies showed that the mechanism of F- adsorption on Al-DA involved ion exchange and the formation of F-Al bonds.

Quantitative MRI identifies lesional and non-lesional abnormalities in MOGAD.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a distinct central nervous system (CNS) disorder that shares features with multiple sclerosis (MS) and may be misdiagnosed as MS. MOGAD and MS share a frequently relapsing clinical course and lesions with inflammatory demyelinating pathology. One key feature of MS pathology is tissue damage in normal-appearing white matter (NAWM) outside of discrete lesions, whereas the extent to which similar non-lesional damage occurs in MOGAD is not known and could be assessed using qGRE. The goal of this study was to examine the brains of people with MOGAD using quantitative gradient-recalled echo (qGRE) magnetic resonance imaging and to compare tissue damage with MS patients matched for disability. METHODS: MOGAD and MS patients were recruited to match in terms of age and disability. Similarly aged healthy control (HC) data were drawn from existing studies. qGRE brain imaging of HC (N = 15), MOGAD (N = 17), and MS (N = 15) patients was used to examine the severity and extent of tissue damage within and outside of discrete lesions. The qGRE metric R2t* is sensitive to changes in tissue microstructure and was measured in white matter lesions (WMLs), NAWM, cortical (CGM) and deep gray matter (DGM). Statistical inference was performed with linear models. RESULTS: R2t* was reduced in CGM (p = 0.00047), DGM (p = 0.0055) and NAWM (p = 0.0019) in MOGAD and MS compared to similar regions in age-matched HCs. However, the degree of R2t* reduction in all these regions was less in the MOGAD patients compared with MS. WMLs in MOGAD demonstrated reduced R2t* compared to NAWM but this reduction was modest compared to changes associated with WMLs in MS (p = 0.026). CONCLUSION: These results demonstrate abnormalities in lesional and non-lesional CNS tissues in MOGAD that are not detectable on standard MRI. The abnormalities seen in NAWM, CGM, and DGM were less severe in MOGAD compared to MS. MOGAD-related WMLs showed reduced R2t*, but were less abnormal than WMLs in MS. These data reveal damage to non-lesional tissues in two different demyelinating diseases, suggesting that damage outside of WMLs may be a common feature of demyelinating diseases. The lesser degree of R2t* abnormality in MOGAD tissues compared to MS suggests less underlying tissue damage and may underlie the greater propensity for recovery in MOGAD.

Rotating characteristics and stability analysis of unsymmetrical magnetically suspended motor.

The rotating characteristic and the stability analysis of unsymmetrical magnetically suspended motor (MSM) are investigated in the article. Firstly, the dynamic functions of unsymmetrical MSM with different moment of inertia ratios and suspension span ratios are developed. Based on the equation of radial rotation, the open-loop pole and the frequency response are analyzed, so relationships among critical whirling frequency, moment of inertia ratio and suspension span ratio are established. Moreover, relationships among rotating characteristic, moment of inertia ratio and suspension span ratio are investigated, and then the rotation stability criterion of unsymmetrical MSM based on dual-frequency bode diagram is developed. Finally, the results prove that the proposed rotation analysis method is a potential way to analyze rotating characteristic of unsymmetrical MSM.

Adsorption Characteristics and Charge Transfer Kinetics of Fluoride in Water by Different Adsorbents.

Water containing high concentrations of fluoride is widely distributed and seriously harmful, largely because long-term exposure to fluoride exceeding the recommended level will lead to fluorosis of teeth and bones. Therefore, it is imperative to develop cost-effective and environmentally friendly adsorbents to remove fluoride from polluted water sources. In this study, diatomite (DA), calcium bentonite (CB), bamboo charcoal (BC), and rice husk biochar (RHB) were tested as adsorbents to adsorb fluoride (F-) from water, and this process was characterized by scanning electron microscopy (FEI-SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The effects of pH, dosage, and the initial mass concentration of each treatment solution upon adsorption of F- were determined. Kinetic and thermodynamic models were applied to reveal the mechanism of defluoridation, and an orthogonal experiment was designed to obtain the optimal combination of conditions. The results show that the surfaces of CB, BC, and RHB have an irregular pore structure and rough surface, whereas DA has a rich pore structure, clear pores, large specific surface area, and high silica content. With regard to the adsorption process for F-, DA has an adsorption complex electron interaction; that of CB, BC, and RHB occur mainly via ion exchange with positive and negative charges; and CB on F- relies on chemical electron bonding adsorption. The maximum adsorption capacity of DA can reach 32.20 mg/g. When the mass concentration of fluoride is 100 mg/L, the pH value is 6.0 and the dosage is 4.0 g/L; the adsorption rate of F- by DA can reach 91.8%. Therefore, we conclude that DA soil could be used as an efficient, inexpensive, and environmentally friendly adsorbent for fluoride removal, perhaps providing an empirical basis for improving the treatment of fluorine-containing water in the future.

Multiple pollutants in groundwater near an abandoned Chinese fluorine chemical park: concentrations, correlations and health risk assessments.

Contamination and adverse effects from various pollutants often appear in abandoned industrial regions. Thus, nine groundwater samples were collected from the vicinity of the fluorochemical industry in Fuxin City, Liaoning Province, to determine concentrations of the ten heavy metals arsenic (As), chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), manganese (Mn), zinc (Zn), iron (Fe) and mercury(Hg), as well as those of fluorine (F-) and eighteen poly- and perfluorinated substances (PFASs), analyse correlation relationships, and assess the health risks for different age groups. The results showed that the levels of fluorine (F-) (0.92-4.42 mg·L-1), Mn (0.0005-4.91 mg·L-1) and Fe (1.45-5.61 mg·L-1) exceeded the standard limits for drinking water. Short chain perfluorobutanoic acid (PFBA) (4.14-2501.42 ng·L-1), perfluorobutane sulfonate (PFBS) (17.07-51,818.61 ng·L-1) and perfluorohexanoic acid (PFHxA) (0.47-936.32 ng·L-1) were the predominant substances from the PFASs group. No individual PFASs levels had significant relationships with F- or heavy metal contents. There was a positive relationship between short chain PFASs concentrations and water depth and a negative relationship between long chain PFASs concentration and water depth. The hazard quotient (HQ) decreased in the order F- > heavy metals > PFASs and also decreased for older age groups. In addition, As, Fe, Mn and perfluorooctanoic acid (PFOA) were the main sources of risk from the heavy metal and PFASs groups, respectively.

Stronger Microstructural Damage Revealed in Multiple Sclerosis Lesions With Central Vein Sign by Quantitative Gradient Echo MRI.

Background: Multiple sclerosis (MS) lesions typically form around a central vein that can be visualized with FLAIR* MRI, creating the central vein sign (CVS) which may reflect lesion pathophysiology. Herein we used gradient echo plural contrast imaging (GEPCI) MRI to simultaneously visualize CVS and measure tissue damage in MS lesions. We examined CVS in relation to tissue integrity in white matter (WM) lesions and among MS subtypes. Objective: We aimed to determine if CVS positive lesions were specific to MS subtype, if CVS can be detected consistently among readers using the GEPCI method, and if there were differences in tissue damage in lesions with vs without CVS. Subjects and Methods: Thirty relapsing-remitting MS (RRMS) subjects and 38 primary and secondary progressive MS (PMS) subjects were scanned with GEPCI protocol at 3T. GEPCI T2*-SWI images were generated to visualize CVS. Two investigators independently evaluated WM lesions for CVS and measured lesion volumes. To estimate tissue damage severity, total lesion volume, and mean lesion volume, R2t*-based tissue damage score (TDS) of individual lesions and tissue damage load (TDL) were measured for CVS+, CVS-, and confluent lesions. Spearman correlations were made between MRI and clinical data. One-way ANCOVA with age and sex as covariates was used to compare measurements of CVS+ vs CVS- lesions in each individual. Results: 398 of 548 lesions meeting inclusion criteria showed CVS. Most patients had ≥40% CVS+ lesions. CVS+ lesions were present in similar proportion among MS subtypes. Interobserver agreement was high for CVS detection. CVS+ and confluent lesions had higher average and total volumes vs CVS- lesions. CVS+ and confluent lesions had more tissue damage than CVS- lesions based on TDL and mean TDS. Conclusion: CVS occurred in RRMS and PMS in similar proportions. CVS+ lesions had greater tissue damage and larger size than CVS- lesions.

Occurrence characteristics and health risk assessment of per- and polyfluoroalkyl substances from water in residential areas around fluorine chemical industrial areas, China.

Recently, identifying the contamination status and assessing the health risk of per- and polyfluoroalkyl substances (PFASs) in surface water and groundwater have been of great significance. Eighteen individual PFASs were analyzed in thirty-three surface/groundwater samples during one period in a fluorine chemical park (Park A) and during two periods in Park B. The mean total concentration of 18 PFASs (∑PFASs) in Park A (9104.63 ng·L-1) was significantly higher than that in the wet season (WS) (801.68 ng·L-1) or DS (714.64 ng·L-1) in Park B. The perfluorobutane sulfonate (PFBS) was the predominant substance in the two parks, and the maximum concentration in groundwater exceeded 10,000 ng·L-1. The contamination status in the wet season (WS) was higher than that in the dry season (DS) in Park B. The ∑PFASs in Park A presented an increasing tendency following the groundwater flow direction, whereas this rule was limited to all periods in Park B. Two relative source contributions (RSCs) of 20% or 100% allowed assessing the PFASs risk to different age groups, and the results revealed that some PFASs (4 ≤ C ≤ 7 or 9 ≤ C ≤ 12) were identified as having a low risk quotient (RQ), except for perfluorooctane sulfonate (PFOS) and PFOA (C = 8). The RQmix value mainly relies on PFOA and PFOS, with a larger contribution rate of 80-90%. All assessed cases (case 1, case 2, case 3, and case 4) in all age groups revealed that infants were vulnerable to PFASs influence, followed by children, teenagers, and adults.

Evaluating brain damage in multiple sclerosis with simultaneous multi-angular-relaxometry of tissue.

OBJECTIVE: Multiple sclerosis (MS) is a common demyelinating central nervous system disease. MRI methods that can quantify myelin loss are needed for trials of putative remyelinating agents. Quantitative magnetization transfer MRI introduced the macromolecule proton fraction (MPF), which correlates with myelin concentration. We developed an alternative approach, Simultaneous-Multi-Angular-Relaxometry-of-Tissue (SMART) MRI, to generate MPF. Our objective was to test SMART-derived MPF metric as a potential imaging biomarker of demyelination. METHODS: Twenty healthy control (HC), 11 relapsing-remitting MS (RRMS), 22 progressive MS (PMS), and one subject with a biopsied tumefactive demyelinating lesion were scanned at 3T using SMART MRI. SMART-derived MPF metric was determined in normal-appearing cortical gray matter (NAGM), normal-appearing subcortical white matter (NAWM), and demyelinating lesions. MPF metric was evaluated for correlations with physical and cognitive test scores. Comparisons were made between HC and MS and between MS subtypes. Furthermore, correlations were determined between MPF and neuropathology in the biopsied person. RESULTS: SMART-derived MPF in NAGM and NAWM were lower in MS than HC (p < 0.001). MPF in NAGM, NAWM and lesions differentiated RRMS from PMS (p < 0.01, p < 0.001, p < 0.001, respectively), whereas lesion volumes did not. MPF in NAGM, NAWM and lesions correlated with the Expanded Disability Status Scale (p < 0.01, p < 0.001, p < 0.001, respectively) and nine-hole peg test (p < 0.001, p < 0.001, p < 0.01, respectively). MPF was lower in the histopathologically confirmed inflammatory demyelinating lesion than the contralateral NAWM and increased in the biopsied lesion over time, mirroring improved clinical performance. INTERPRETATION: SMART-derived MPF metric holds potential as a quantitative imaging biomarker of demyelination and remyelination.

Different clinical characteristics and survival between surgically resected pure and combined small cell lung cancer.

BACKGROUND: Small cell lung cancer (SCLC) is the most malignant and common form of neuroendocrine lung cancer with pure (P-SCLC) and combined subtypes (C-SCLC). However, little is known about the differences between these two groups and in this study we aimed to provide a more comprehensive insight into SCLC. METHODS: Data from 580 postoperative patients with pathologically confirmed SCLC in Shanghai Chest Hospital from January 2010 to December 2020 were collected retrospectively. The clinical characteristics and prognosis were analyzed. RESULTS: A total of 357 P-SCLC patients and 223 C-SCLC patients were included. The results indicated that P-SCLC appeared to have a higher proportion of being located in the middle lobe than C-SCLC. The incidences of P-SCLC in patients with visceral pleural invasion (VPI) and in stage II were higher than C-SCLC, while C-SCLC was more likely to be accompanied by higher incidences of epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) rearrangement, and higher levels of CEA, SCCA and CYFRA21-1 than P-SCLC. The most common were SCLC combined with large cell neuroendocrine components among 223 C-SCLCs. Survival analysis confirmed a more favorable disease-free survival (DFS) (p = 0.016) and overall survival (OS) (p = 0.024) in patients with P-SCLCs compared with C-SCLCs. Histological type, tumor location, pN stage, adjuvant chemotherapy, serum NSE and CA125 levels were independent risk factors for survival rate in SCLC. In addition, adjuvant chemotherapy was beneficial in improving stage I P-SCLC and C-SCLC DFS and OS rates, and similar results were not seen in adjuvant radiation therapy. CONCLUSIONS: Patients with C-SCLC have a poorer prognosis than P-SCLC patients. We determined that large cell neuroendocrine carcinoma was the most common additional component of C-SCLC, and patients with this component appeared to have a longer DFS and OS than other combined components.

A theoretical study of the mechanism for the homogeneous catalytic reversible dehydrogenation-hydrogenation of nitrogen heterocycles.

A mechanism for the dehydrogenation reaction of 1,2,3,4-tetrahydroquinoline to quinoline derivatives, catalyzed by a Cp*Ir complex containing a 2-pyridonate ligand, is proposed and supported by theoretical calculations at the B3LYP level. The proposed mechanism involves two stages which are all thermodynamically unfavorable (endothermic by 36.3 kcal mol(-1) and 18.4 kcal mol(-1), respectively). The apparent activation energies of the first and second stages of the reaction are 30.8 kcal mol(-1) and 34.0 kcal mol(-1), respectively, and are considered overestimates of the entropy change of reaction. Owing to a decrease in the oxidative ability of iridium(III) coordinated to large electronegative nitrogen and chlorine, ligand promoted hydrogen abstraction is crucial at both stages of dehydrogenation, in which the oxidation state of iridium(III) does not change, and the ligand 2-pyridonate is converted to 2-hydroxypyridine. Cp*Ir(C(5)NH(4)OH)ClH, an important intermediate, releases hydrogen through an energy barrier of 23.5 kcal mol(-1).

The airborne inertially stabilized platform suspend by an axial-radial integrated active magnetic actuator system.

INTRODUCTION: The inertial stabilization platform (ISP) is widely used in the earth observation system to stably track the line of sight of the payload because it could isolate vibrations and angular motions of the aviation platform. OBJECTIVES: an active magnetic actuator (AMA) system integrating the axial and the radial control is used to levitate the azimuth gimbal to improve attitude stabilization precision and dynamic performance of the ISP, and then the dynamic model of azimuth gimbal is developed. METHODS: The magnetic force and the gimbal torque of the axial-radial integrated AMA system are investigated, and the attitude information of the suspended azimuth gimbal is measured. RESULTS: The attitude stabilization precision of azimuth gimbal is confined at 0.02°, and the control bandwidth of the axial-radial integrated AMA system could exceed 100 Hz. CONCLUSION: the ISP with an axial-radial integrated AMA system has better attitude stabilization precision and wider control frequency than the pure mechanical ISP, so it is potential to be applied in the airborne remote sensing system to improve the measurement precision.

The force effects of two types of polyethylene terephthalate glyc-olmodified clear aligners immersed in artificial saliva.

Numerous factors can influence the force exerted by clear aligners on teeth. This study aimed to investigate the stability of the force delivered by two different material appliances. 90 clear aligners with 2 materials and three different activations were designed and fabricated. Then, a device was employed to measure the force generated by the two types of PET-G material appliances immersed in artificial saliva for 0, 3, 7, 10, 14 days. Scanning electron microscopy was applied to observe the morphologic alterations on the aligner surfaces, respectively. The forces generated by different activation appliance exhibited differently, 0.0 mm < 0.1 mm < 0.2 mm. In addition, increasing the immersion times and the orthodontic force also decreased, but the forces decreased differently. Compared with the forces of conventional PETG appliances with 0.20 mm activation, the modified PETG appliances with the same activation exhibited significantly higher mean force. When comparing the mean force for modified PETG appliances after 10 and 14 days with conventional PETG appliances, the delivery forces exhibited significant differences (P < 0.05). The force delivered by both materials decreased obviously following artificial saliva immersion, and the force generated by modified aligners exhibited better stability than conventional aligners.