137 research outputs found
Erosion-induced CO2 flux of small watersheds
Soil erosion not only results in severe ecological damage, but also interferes with soil organic carbon formation and decomposition, influencing the global green-house effect. However, there is controversy as to whether a typical small watershed presumed as the basic unit of sediment yield acts as a CO2 sink or source. This paper proposes a discriminant equation for the direction of CO2 flux in small watersheds, basing on the concept of Sediment Delivery Ratio (SDR). Using this equation, watersheds can be classified as Sink Watersheds, Source Watersheds, or Transition Watersheds, noting that small watersheds can act either as a CO2 sink or as a CO2 source. A mathematical model for calculating the two discriminant coefficients in the equation is set up to analyze the conditions under which each type of watershed would occur. After assigning the model parameter values at three levels (low, medium, and high), and considering 486 scenarios in total, the influences are examined for turnover rate of the carbon pool, erosion rate, deposition rate, cultivation depth and period. The effect of adopting conservation measures like residue return, contour farming, terracing, and conservation tillage is also analyzed. The results show that Sink Watersheds are more likely to result in conditions of high erosion rate, long cultivation period, high deposition rate, fast carbon pool turnover rate, and small depth of cultivation; otherwise, Source Watersheds would possibly occur. The results also indicate that residue return and conservation tillage are beneficial for CO2 sequestration. (C) 2012 Elsevier B.V. All rights reserved.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)EI0ARTICLE101-11094-9
Developing an immunocompetent mouse model of renal cell carcinoma bone metastasis
https://openworks.mdanderson.org/sumexp23/1095/thumbnail.jp
EM Decay of X(3872) as the charmonium
The recently BaBar results raise the possibility that X(3872) has negative
parity. This makes people reconsider assigning X(3872) to the state. In this paper we give a general form of the wave function of
mesons. By solving the instantaneous Bethe-Salpeter equation, we get
the mass spectrum and corresponding wave functions. We calculate
electromagnetic decay widths of the first state which we assume to be
the X(3872) particle. The results are keV, eV and keV. The ratio of branch fractions
of the second and first channel is about 0.002, which is inconsistent with the
experimental value . So X(3872) is unlikely to be a
charmonium state. In addition, we obtain a relatively large decay width for
channel which is keV.Comment: Revised versio
Assessment of flooding impacts in terms of sustainability in mainland China
An understanding of flood impact in terms of sustainability is vital for long-term disaster risk reduction. This paper utilizes two important concepts: conventional insurance related flood risk for short-term damage by specific flood events, and long-term flood impact on sustainability. The Insurance Related Flood Risk index, IRFR, is defined as the product of the Flood Hazard Index (FHI) and Vulnerability. The Long-term Flood Impact on Sustainability index. LFIS, is the ratio of the flood hazard index to the Sustainable Development Index (SDI). Using a rapid assessment approach, quantitative assessments of IRFR and LFIS are carried out for 2339 counties and cities in mainland China. Each index is graded from 'very low' to 'very high' according to the eigenvalue magnitude of cluster centroids. By combining grades of FHI and SDI, mainland China is then classified into four zones in order to identify regional variations in the potential linkage between flood hazard and sustainability. Zone I regions, where FHI is graded 'very low' or low' and SDI is 'medium' to 'very high', are mainly located in western China. Zone II regions, where FHI and SDI are 'medium' or 'high', occur in the rapidly developing areas of central and eastern China. Zone III regions, where FHI and SDI are 'very low' or 'low', correspond to the resource-based areas of western and north-central China. Zone IV regions, where FHI is 'medium' to 'very high' and SDI is 'very low' to 'low', occur in ecologically fragile areas of south-western China. The paper also examines the distributions of IRFR and LFIS throughout mainland China. Although 57% of the counties and cities have low IRFR values, 64% have high LFIS values. The modal values of LFIS are ordered as Zone I < Zone II approximate to Zone III < Zone IV; whereas the modal values of IRFR are ordered as Zone I < Zone III < Zone IV < Zone II. It is recommended that present flood risk policies be altered towards a more sustainable flood risk management strategy in areas where LFIS and IRFR vary significantly, with particular attention focused on Zone IV regions, which presently experience poverty and a deteriorating eco-system. (C) 2010 Elsevier Ltd. All rights reserved
First-in-human, open-label dose-escalation and dose-expansion study of the safety, pharmacokinetics, and antitumor effects of an oral ALK inhibitor ASP3026 in patients with advanced solid tumors
Abstract Background ASP3026 is a second-generation anaplastic lymphoma kinase (ALK) inhibitor that has potent in vitro activity against crizotinib-resistant ALK-positive tumors. This open-label, multicenter, first-in-human phase I study ( NCT01284192 ) assessed the safety, pharmacokinetic profile, and antitumor activity of ASP3026. Methods Advanced solid tumor patients received oral ASP3026 in 3 + 3 dose-escalation cohorts at doses of 25–800 mg once daily in 28-day cycles. The endpoints were to identify the maximum tolerated dose (MTD), the recommended phase II dose (RP2D), and the pharmacokinetic profile of ASP3026. A phase Ib expansion cohort enrolled patients with metastatic, crizotinib-resistant ALK-positive solid tumors at the RP2D, and response was evaluated by RECIST 1.1. Results The dose-escalation cohort enrolled 33 patients, including three crizotinib-resistant, ALK-positive patients, and the dose-expansion cohort enrolled another 13 crizotinib-resistant, ALK-positive non-small cell lung cancer (NSCLC) patients. ASP3026 demonstrated both linear pharmacokinetics and dose-proportional exposure for area under the plasma concentration–time curve and maximum concentration observed with a median terminal half-life of 35 h, supporting the daily dosing. Grade 3 rash and elevated transaminase concentrations were dose-limiting toxicities observed at 800 mg; hence, 525 mg daily was the MTD and RP2D. The most common treatment-related adverse events were nausea (38 %), fatigue (35 %), and vomiting (35 %). Among the 16 patients with crizotinib-resistant ALK-positive tumors (15 NSCLC, 1 neuroblastoma), eight patients achieved partial response (overall response rate 50 %; 95 % confidence interval 25–75 %) and seven patients (44 %) achieved stable disease. Conclusions ASP3026 was well tolerated and had therapeutic activity in patients with crizotinib-resistant ALK-positive advanced tumors. Trial registration ClinTrials.gov: NCT0128419
Investigation of Stilbenoids as Potential Therapeutic Agents for Rotavirus Gastroenteritis
Rotavirus (RV) infections cause severe diarrhea in infants and young children worldwide. Vaccines are available but cost prohibitive for many countries and only reduce severe symptoms. Vaccinated infants continue to shed infectious particles, and studies show decreased efficacy of the RV vaccines in tropical and subtropical countries where they are needed most. Continuing surveillance for new RV strains, assessment of vaccine efficacy, and development of cost effective antiviral drugs remain an important aspect of RV studies. This study was to determine the efficacy of antioxidant and anti-inflammatory stilbenoids to inhibit RV replication. Peanut (A. hypogaea) hairy root cultures were induced to produce stilbenoids, which were purified by high performance countercurrent chromatography (HPCCC) and analyzed by HPLC. HT29.f8 cells were infected with RV in the presence stilbenoids. Cell viability counts showed no cytotoxic effects onHT29.f8 cells. Viral infectivity titers were calculated and comparatively assessed to determine the effects of stilbenoid treatments. Two stilbenoids, trans-arachidin-1 and trans-arachidin-3, show a significant decrease in RV infectivity titers.Western blot analyses performed on the infected cell lysates complemented the infectivity titrations and indicated a significant decrease in viral replication. These studies show the therapeutic potential of the stilbenoids against RV replication
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An Integrated Multidisciplinary Evaulation Platform and Early Experience for Precision Therapy in Resectable NSCLC
Lung cancer is the leading cause of cancer related deaths in the US, with 85% of cases classified as non-small cell lung cancer (NSCLC). 20-25% of patients with NSCLC present with resectable disease
The molecular basis of beta-thalassemia intermedia in southern China: genotypic heterogeneity and phenotypic diversity
<p>Abstract</p> <p>Background</p> <p>The clinical syndrome of thalassemia intermedia (TI) results from the β-globin genotypes in combination with factors to produce fetal haemoglobin (HbF) and/or co-inheritance of α-thalassemia. However, very little is currently known of the molecular basis of Chinese TI patients.</p> <p>Methods</p> <p>We systematically analyzed and characterized β-globin genotypes, α-thalassemia determinants, and known primary genetic modifiers linked to the production of HbF and the aggravation of α/β imbalance in 117 Chinese TI patients. Genotype-phenotype correlations were analyzed based on retrospective clinical observations.</p> <p>Results</p> <p>A total of 117 TI patients were divided into two major groups, namely heterozygous β-thalassemia (n = 20) in which 14 were characterized as having a mild TI with the Hb levels of 68-95 g/L except for five co-inherited ααα<sup>anti-3.7 </sup>triplication and one carried a dominant mutation; and β-thalassemia homozygotes or compound heterozygotes for β-thalassemia and other β-globin defects in which the β<sup>+</sup>-thalassemia mutation was the most common (49/97), hemoglobin E (HbE) variants was second (27/97), and deletional hereditary persistence of fetal hemoglobin (HPFH) or δβ-thalassemia was third (11/97). Two novel mutations, Term CD+32(A→C) and Cap+39(C→T), have been detected.</p> <p>Conclusions</p> <p>Chinese TI patients showed considerable heterogeneity, both phenotypically and genotypically. The clinical outcomes of our TI patients were mostly explained by the genotypes linked to the β- and α-globin gene cluster. However, for a group of 14 patients (13 β<sup>0</sup>/β<sup>N </sup>and 1 β<sup>+</sup>/β<sup>N</sup>) with known heterozygous mutations of β-thalassemia and three with homozygous β-thalassemia (β<sup>0</sup>/β<sup>0</sup>), the existence of other causative genetic determinants is remaining to be molecularly defined.</p
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