260 research outputs found
Rational Synthesis Of Catalysts For Biomass Conversion
With climate change due to global warming, the production of hydrocarbon fuels and chemicals from renewable biomass resource has become more pressing in recent decades. The biggest challenge in biomass conversion is to develop active, selective and stable catalysts for particular applications. The objective of this research is to optimize catalytic performance for hydrodeoxygenation (HDO) and hydrogenation reactions by enhancing the stability of the support, tuning metal particle size, and controlling surface composition.
The high content of water in bio-oil and the aqueous environment of the upgrading process requires a hydrothermally stable catalyst. The hydrothermal stability has been effectively improved at 220oC by various means: the introduction of Zr, carbon coating on silica, and the development of mesoporous alumina. Monometallic and bimetallic catalysts were prepared on these stable supports by strong electrostatic adsorption (SEA) and ultra-small nanoparticles (\u3c2 nm) were synthesized. Stability tests at the bio-oil HDO reaction temperature of 300oC revealed that the mesoporous alumina outperformed the other supports in terms surface area and pore structure maintenance, and metal particle stability. Mesoporous alumina-supported Pt/Ru and Cu/Ni were tested for HDO of bio-oil at USDA. Two methods were applied to control metal particle sizes. In the first, SEA-derived Ru and Pt nanoparticles (\u3c2 nm) supported on mesoporous silica were treated at elevated
temperatures (800oC and 900oC) in humidified hydrogen to achieve series of catalysts with particle sizes ranging from 1 to 5 nm. This treatment, however, significantly deteriorated the support. A milder method was demonstrated via charge enhanced dry impregnation (CEDI): Pt particles were grown from about 1 to 10 nm on a variety of common supports by adding excess chloride to the impregnating solution. Particle size sensitivity to chloride was compared on various supports.
The effect on furfural hydrogenation of controlling of surface composition of bimetallic nanoparticles was demonstrated with silica supported PdCu and PdCo catalysts prepared by co-SEA, SEA followed by Electroless Deposition (SEA-ED), and dry impregnation (co-DI). SEA and co-SEA preparations yielded ultra-small (about 1 nm) single metal Pd, Cu, and Co and homogeneously alloyed PdCu and PdCo nanoparticles. Cu could be added as partial monolayer shells via ED to the SEA-synthesized Pd cores. The reaction pathway and product yield were seen to be a sensitive function of the synthesis method and corresponding surface composition
Identification of novel somatic fusions of ERG-VEGFA, TMPRSS2-ERG, and VEGFA-TMPRSS2 in prostate cancer treated with anlotinib and androgen deprivation therapy: A case report
The TMPRSS2-ERG fusion gene has frequently been found in prostate cancer and is associated with malignancy. Identifying novel fusions will help to stratify patients and establish patient-tailored therapies. A 78-year-old man presented to our hospital with severe symptoms of urinary urgency and frequency for 2 years, as well as severe bone pain for 1 year. He was diagnosed with metastatic prostate cancer with a Gleason score of 5 + 5. Three gene fusions, ERG_VEGFA, TMPRSS2_ERG, and VEGFA_TMPRSS2, were identified in the patient\u27s prostate cancer tissue. Notably, administration of the tyrosine kinase inhibitor, anlotinib, in combination with a gonadotropin-releasing hormone agonist (GnRHa) and abiraterone, reduced the patient\u27s bone pain and also stabilized his prostate cancer for more than 2 years. This is the first report of somatic fusions among the VEGFA, ERG, and TMPRSS2 genes in cancer tissues from a patient with prostate cancer who responded well to antiangiogenic treatment combined with a GnRHa and abiraterone
Petrogenesis of the Northwest Africa 4734 basaltic lunar meteorite
We report the petrography, mineralogy, trace element abundance geochemistry, and Pb–Pb geochronology of the lunar meteorite Northwest Africa (NWA) 4734 and make a comparison with the LaPaz Icefield (LAP) 02205/02224 low-Ti lunar basaltic meteorites. NWA 4734 is an unbrecciated low-Ti mare basalt composed mainly of subophitic-textured pyroxene (60 vol%) and plagioclase (30%). Pyroxene, plagioclase, and olivine exhibit large compositional variations and intra-grain chemical zoning. Pyroxene and plagioclase in NWA 4734 have rare earth element (REE) concentrations and patterns similar to those of the LAPs. The crystallization age of NWA 4734, determined in situ in baddeleyite, is 3073 ± 15 Ma (2σ), nearly identical to that of the LAPs (3039 ± 12 Ma). NWA 4734 and the LAPs have similar textures, modal abundances, mineral chemistry, and crystallization ages, and are most likely source-crater paired on the Moon.
One baddeleyite grain in LAP 02224 displays distinctively older and spatially variable ages, from 3349 ± 62 to 3611 ± 62 Ma (2σ), similar to another baddeleyite grain (3109 ± 29 to 3547 ± 21 Ma) reported by Zhang et al. (2010) for the same meteorite. Raman spectra, cathodoluminescence, and stoichiometric studies of the baddeleyite suggest that the two older grains were not endogenic but were trapped by the parental magma. Equilibrium partition calculation shows that the parental melt from which the NWA 4734 plagioclase crystallized has much lower REE contents than its whole rock, indicating an open system during magma evolution. NWA 4734 could have originated from a parental melt with REE concentrations similar to that of the Apollo 12 olivine basalt. The magma likely assimilated a small amount (∼4 wt%) of KREEP-rich material during its ascent through the lunar crust
Lung Nodule Segmentation and Uncertain Region Prediction with an Uncertainty-Aware Attention Mechanism
Radiologists possess diverse training and clinical experiences, leading to
variations in the segmentation annotations of lung nodules and resulting in
segmentation uncertainty.Conventional methods typically select a single
annotation as the learning target or attempt to learn a latent space comprising
multiple annotations. However, these approaches fail to leverage the valuable
information inherent in the consensus and disagreements among the multiple
annotations. In this paper, we propose an Uncertainty-Aware Attention Mechanism
(UAAM) that utilizes consensus and disagreements among multiple annotations to
facilitate better segmentation. To this end, we introduce the Multi-Confidence
Mask (MCM), which combines a Low-Confidence (LC) Mask and a High-Confidence
(HC) Mask.The LC mask indicates regions with low segmentation confidence, where
radiologists may have different segmentation choices. Following UAAM, we
further design an Uncertainty-Guide Multi-Confidence Segmentation Network
(UGMCS-Net), which contains three modules: a Feature Extracting Module that
captures a general feature of a lung nodule, an Uncertainty-Aware Module that
produces three features for the the annotations' union, intersection, and
annotation set, and an Intersection-Union Constraining Module that uses
distances between the three features to balance the predictions of final
segmentation and MCM. To comprehensively demonstrate the performance of our
method, we propose a Complex Nodule Validation on LIDC-IDRI, which tests
UGMCS-Net's segmentation performance on lung nodules that are difficult to
segment using common methods. Experimental results demonstrate that our method
can significantly improve the segmentation performance on nodules that are
difficult to segment using conventional methods.Comment: 10 pages, 10 figures. We have reported a preliminary version of this
work in MICCAI 202
The impact of the Pan-African-aged tectonothermal event on high-grade rocks at Mount Brown, East Antarctica
This study presents monazite and rutile U–Pb and hornblende and biotite 40Ar/39Ar
geochronological data for high-grade rocks of the eastern Grenville-aged Rayner orogen at Mount
Brown in order to analyse the extent and degree of Pan-African-aged reworking. Monazite from
paragneiss yields U–Pb ages of 910 Ma for larger granular grains and 670–630 Ma for smaller globular
beads around garnet porphyroblasts or hosted by symplectites. Rutile from leucogneiss yields U–Pb ages
of 520–515 Ma. Hornblende and biotite from different rock types yield 40Ar/39Ar plateau ages of 744
and 520–505 Ma, respectively. Combining these results with published zircon U–Pb age data suggests
that granulite facies metamorphism occurred at 910 Ma, with a local low-temperature fluid flow event at
670–630 Ma and thermal reworking at 520–505 Ma. The older age of 744 Ma may reflect cooling or
partial resetting of the hornblende 40Ar/39Ar system, indicating that Pan-African-aged reworking did not
exceed temperatures much higher than the hornblende Ar closure temperature. These data also suggest
that the complete isotopic resetting of some minerals may occur without the growth of new mineral
phases, providing an example of the style of reworking that is likely to occur in polymetamorphic terranes.This research was supported by the National Natural
Science Foundation of China (No. 41530209), Central
Public-Interest Scientific Institution Basal Research Fund
(No. JYYWF201819) and Geological Investigation
Project of the Chinese Geological Survey (No.
DD20190579)
Different RET Gene Mutation-Induced Multiple Endocrine Neoplasia Type 2A in 3 Chinese Families
BACKGROUD: Multiple endocrine neoplasia type 2A (MEN2A) is a condition with inherited autosomal dominant mutations in RET (rearranged during transfection) gene that predisposes the carrier to extremely high risk of medullary thyroid cancer (MTC) and other MEN2A-associated tumors such as parathyroid cancer and/or pheochromocytoma. Little is reported about MEN2A syndrome in the Chinese population.
METHODS: All members of the 3 families along with specific probands of MEN2A were analyzed for their clinical, laboratory, and genetic characteristics. Exome sequencing was performed on the 3 probands, and specific mutation in RET was further screened on each of the family members.
RESULTS: Different mutations in the RET gene were identified: C634S in Family 1, C611Y in Family 2, and C634Y in Family 3. Proband 1 mainly showed pheochromocytoma with MTC, both medullary thyroid carcinoma and pheochromocytoma were seen in proband 2, and proband 3 showed medullary thyroid carcinoma.
CONCLUSION: The genetic evaluation is strongly recommended for patients with a positive family history, early onset of age, or multiple sites of masses. If the results verified the mutations of RET gene, thyroidectomy should be undertaken as the guide for better prognosis
Carbonization Resistance of Reinforced Concrete under Bending Load
Fly ash has been used more and more often to take the place of cement as the admixture of concrete in the construction of concrete buildings. However, with the increase of the carbon dioxide (CO2) concentration in the atmosphere, carbonization damage has become an essential factor affecting the durability of fly ash concrete. Here a long-term bending load device was developed to explore how the pouring surface and the bending load affect the carbonization resistance of reinforced concrete under rapid carbonization. In addition, the relationship between the bending-tension and bending-compression loads with respect to the carbonization damage of test blocks was also investigated. Due to the differences in the concrete compactness, the carbonization depth of the pouring surface was found to be greater than that of the bottom at the same position. To a certain extent, with the increasing bending-load stress, different carbonization resistances were observed in the bending-tension zone and the bending-compression zone of the concrete test blocks. Meanwhile, to study the relationship between the carbonization damages in the bending-tension zone and the bending-compression zone of concrete test blocks, a carbonization influence coefficient of bending tension-compression load was proposed, which provides a convenient and scientific guidance for the detection and evaluation of concrete carbonization damages in practical engineering.
 
The VHL/HIF Axis in the Development and Treatment of Pheochromocytoma/Paraganglioma
Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors originating from chromaffin cells in the adrenal medulla (PCCs) or extra-adrenal sympathetic or parasympathetic paraganglia (PGLs). About 40% of PPGLs result from germline mutations and therefore they are highly inheritable. Although dysfunction of any one of a panel of more than 20 genes can lead to PPGLs, mutations in genes involved in the VHL/HIF axis includin
Correlation between the Hemoglobin, Albumin, Lymphocyte, and Platelet (HALP) Score and Left Ventricular Hypertrophy in Older Patients with Hypertension
Introduction: Hypertension and left ventricular hypertrophy (LVH) have emerged as significant risk factors for cardiovascular events and all-cause mortality. Inflammation and nutrition play critical roles in the development of hypertension and damage to target organs. The HALP Score, which assesses levels of hemoglobin, albumin, lymphocytes, and platelets, is an index closely associated with inflammation and nutrition, and has been demonstrated to be particularly effective in the older population. Hence, the objective of this study was to examine the correlation between the HALP Score and LVH in older patients with hypertension. Methods: We collected and retrospectively analyzed data from 234 older patients, including clinical data, and routine blood, liver function, kidney function, and cardiac ultrasound parameters. All patients were categorized into a non-left ventricular hypertrophy (NLVH) group (n = 131) or an LVH group (n = 103). The association between the HALP Score and LVH was investigated, and potential influencing factors were considered. Results: The LVH group had a significantly lower HALP Score than the NLVH group. Logistic regression analysis revealed that a lower HALP Score and female sex were independent factors associated with LVH in older patients with hypertension (OR = 0.944, 9.962, 95% CI: 0.910–0.979, 3.866–24.300, P = 0.002, <0.001). The area under the curve for the HALP Score in diagnosing LVH in older patients with hypertension was 0.708 (95% CI: 0.641–0.776, P = 0.002). Conclusion: The HALP Score is significantly associated with LVH in older patients with hypertension: lower scores indicate a greater likelihood of LVH. The HALP Score has moderate diagnostic value for LVH in this population
Metformin represses bladder cancer progression by inhibiting stem cell repopulation via COX2/PGE2/STAT3 axis
Cancer stem cells (CSCs) are a sub-population of tumor cells playing essential roles in initiation, differentiation, recurrence, metastasis and development of drug resistance of various cancers, including bladder cancer. Although multiple lines of evidence suggest that metformin is capable of repressing CSC repopulation in different cancers, the effect of metformin on bladder cancer CSCs remains largely unknown. Using the N-methyl-N-nitrosourea (MNU)-induced rat orthotropic bladder cancer model, we demonstrated that metformin is capable of repressing bladder cancer progression from both mild to moderate/severe dysplasia lesions and from carcinoma in situ (CIS) to invasive lesions. Metformin also can arrest bladder cancer cells in G1/S phases, which subsequently leads to apoptosis. And also metformin represses bladder cancer CSC repopulation evidenced by reducing cytokeratin 14 (CK14+) and octamer-binding transcription factor 3/4 (OCT3/4+) cells in both animal and cellular models. More importantly, we found that metformin exerts these anticancer effects by inhibiting COX2, subsequently PGE2 as well as the activation of STAT3. In conclusion, we are the first to systemically demonstrate in both animal and cell models that metformin inhibits bladder cancer progression by inhibiting stem cell repopulation through the COX2/PGE2/STAT3 axis
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