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Background: The role of chemoradiotherapy in unresectable locally advanced pancreatic cancer is still unclear. Methods: Data from patients with unresectable locally advanced pancreatic cancer were extracted from the Surveillance, Epidemiology, and End Results Program database. Univariate and multivariate Cox regression analyses were conducted to identify the independent prognostic factors of survival. Propensity score matching was carried out to minimize the interference of confounding factors. Subgroup analysis was performed to screen the characteristics of patients who would benefit from chemoradiotherapy. Results: A total of 5002 patients with unresectable locally advanced pancreatic cancer were included. Among them, 2423 (48.4%) received chemotherapy, and 2579 (51.6%) received chemoradiotherapy. The median overall survival of all patients was 11 months. Multivariate Cox analysis showed that age (p < 0.001), marital status (p < 0.001), tumor size (p = 0.001), N stage (p = 0.015) and radiotherapy (p < 0.001) were independent prognostic factors of survival. Both before (HR, 0.817; 95% CI, 0.769–0.868; p < 0.001) and after (HR, 0.904; 95% CI, 0.876–0.933; p < 0.001) propensity score matching, chemoradiotherapy significantly improved the median overall survival of patients from 10 to 12 months. Subgroup analysis showed that chemoradiotherapy was significantly associated with improved survival regardless of sex, primary site or N stage. In addition, the following subgroups all significantly benefited from chemoradiotherapy: age ≥ 50 years, not divorced, grade 2–4, tumor size > 2 cm, adenocarcinoma, mucinous adenocarcinoma and white race. Conclusions: Chemoradiotherapy is highly recommended for patients with unresectable locally advanced pancreatic cancer. [ABSTRACT FROM AUTHOR]

A NiH-catalyzed polarity-reversed hydroamination of β,γ-, γ,δ- and δ,ε-unsaturated alkenes with electrophilic anthranils was developed. This reaction proceeds in a highly regio- and chemoselective manner to afford γ, δ and ε-arylamines bearing a carbonyl or alcohol functionality with 100% atom efficiency. Preliminary mechanistic studies indicate that the chemoselectivity is controlled by the base and the alcohol product is derived from the base-catalyzed hydrosilylation of the C＝O bond. [ABSTRACT FROM AUTHOR]

Abstract: The absorber is a key component in a thermally-driven absorption system which significantly influences the whole system performance. The adiabatic spray absorption is one type of absorption process, in which the absorption fluid is dispersed into fine droplets having immense surface exposed to the vapor. In the current investigation, an improved analytical Newman model is presented which can consider the absorption heat effect. Using the model, the absorption characteristics of the adiabatic spray in aqueous lithium bromide solution is studied. The results show that the absorption heat significantly affects the absorption process. When the droplet radius decreases, the absorption rate can be improved and the maximum absorption time can be reduced. The current investigation can result in a better understanding of absorption mechanisms of the adiabatic spray absorption. [Copyright &y& Elsevier]

Abstract: A high-order discrete-time nonlinear system with unknown parameters and Gaussian noise is studied in this paper, and it is shown that under a simple algebraic condition concerning the nonlinearity of the system, there does not exist any feedback controller that globally stabilizes the uncertain system. This impossibility result attempts to understand the capability and limitation of feedback mechanism of a high-order discrete-time nonlinear system and continues a series of previous research on similar first-order systems. This result shows that for the high-order discrete-time nonlinear system studied here, a polynomial corresponding to the first-order principle part of the system determines the limit of the feedback mechanism. [Copyright &y& Elsevier]

Fencing for grazing exclusion has been widely found to have an impact on grassland soil organic carbon (SOC) and total nitrogen (TN), but little is known about the impact of fenced grassland on the changes in deep soil carbon (C) and nitrogen (N) stocks in temperate grasslands. We studied the influence of 30 years fencing on vegetation and deep soil characteristics (0–500 cm) in the semi-arid grasslands of northern China. The results showed that fencing significantly increased the aboveground biomass (AGB), litter biomass (LB), total biomass, vegetation coverage and height, and soil water content and the SOC and TN in the deep soil. The belowground biomass (BGB) did not significantly differ between the fenced and grazed grassland. However, fencing significantly decreased the root/shoot ratio, forbs biomass, pH, and soil bulk density. Meanwhile, fencing has significantly increased the C and N stocks in the AGB and LB but not in the BGB. After 30 years of fencing, the C and N stocks significantly increased in the 0–500 cm soil layer. The accumulation of SOC mainly occurred in the deep layers (30–180 cm), and the accumulation of TN occurred in the soil layers of 0 to 60 cm and 160 to 500 cm. Our results indicate that fencing is an effective way to improve deep soil C and N stocks in temperate grassland of northwest China. There were large C and N stocks in the soil layers of 100 to 500 cm in the fenced grasslands, and their dynamics should not be ignored. [ABSTRACT FROM AUTHOR]

Background: The role of carbohydrate antigen 19‐9 (CA 19‐9) in response assessment among patients with intrahepatic cholangiocarcinoma (iCCA) remains unknown. The authors studied the association of the CA 19‐9 response (defined as a reduction >50% from baseline) with the radiologic response and the outcome in patients with unresectable iCCA. Methods: A prospective cohort of 422 patients who were initially diagnosed with unresectable iCCA, had baseline CA 19‐9 levels ≥100 U/mL, and received treatment with systemic therapies at the authors' institution between January 2017 and December 2021 were enrolled in this study. The radiologic response was assessed using the Response Evaluation Criteria in Solid Tumors version 1.1. A landmark assessment of the CA 19‐9 response and the radiologic response was performed. The associations between CA 19‐9 response and imaging response, progression‐free survival (PFS), and overall survival (OS) were analyzed. Results: Two hundred sixty‐seven patients (63.3%) had a CA 19‐9 response. A CA 19‐9 response was observed in 123 of 132 (93.2%) radiologic responders and in 144 of 290 (49.7%) radiologic nonresponders (p <.001). CA 19‐9 responders outperformed nonresponders in median PFS (10.6 vs. 3.6 months; hazard ratio [HR], 4.8 months; 95% confidence interval [CI], 3.8–6.0 months; p <.001) and OS (21.4 vs. 6.3 months; HR, 5.3 months; 95% CI, 4.2–6.7 months; p <.001). The common independent predictors of both OS and PFS included metastasis, CA 19‐9 nonresponder status, and radiologic nonresponder status in multivariable analysis. Conclusions: CA 19‐9 response is a valuable addition to assess tumor response and is associated with improved outcomes in patients with iCCA. Achieving a CA 19‐9 response should be one of the therapeutic objectives of patients with iCCA after systemic therapies. Plain language summary: A decline in carbohydrate antigen 19‐9 levels from elevated baseline levels should be one of the therapeutic aims of patients with intrahepatic cholangiocarcinoma who are managed with systemic therapies. [ABSTRACT FROM AUTHOR]

Soil respiration (SR) is an important process and the largest source of carbon cycle of terrestrial ecosystems, which has a significant impact on global climate and environmental changes. The fluctuation of temperature and precipitation caused by climate change is a driving force for the dynamic change of SR. Therefore, we established the field experiment with 5 levels of precipitation by rainout shelters and 2 levels of temperature by Open-top Chamber (OTC) to determine the SR dynamic in the desert grassland in northwest China. The results show that: soil temperature (ST) and soil moisture (SM) are affected by changed precipitation and increased temperature, but not greatly. Overall, it can be seen that the SR continue to increase with the precipitation increasing and the temperature rising. SR has no significant correlation with above-ground living biomass (ALB), but is significantly correlated with root biomass (RB), so SR mainly comes from the root system, and ALB and RB both increase with rainfall rising. Soil physical and chemical properties are related to SR, but not significantly. These findings provide a reliable theoretical basis for formulating a reasonable response strategy in desert steppe ecosystems. • Ecological responses of desert-steppe SR to temperature increases and precipitation changes along with their ecological sensitivity indexes. • Correlations between SR, soil temperatures, soil moisture, and other soil properties and plant biomass in the desert grasslands. • This research provides a reliable theoretical basis for formulating a reasonable response strategy for desert steppes. [ABSTRACT FROM AUTHOR]

To overcome the shortcomings of the traditional fuzzy C-means(FCM) clustering algorithm which were simple image feature description and easy distributed by complex grey influence with wrong segmentation, this paper proposed an improved FCM algorithm for image segmentation, combined with universal gravitation principle and local entropy theorem. Firstly, it introduced the image local entropy to accurately measure image node property between two adjacent nodes, and meanwhile computed the node homogeneous value. Then it was taken as the node quality, formed closely relationship using gravity algorithm which made the node grey feature and spatial position combine effectively. The above method solved the problem of the description of node feature isolation of traditional FCM algorithm. Finally, the simulation results show that the presented algorithm can obtain more precise segmentation results from three types of grey non-uniform distribution medical images. [ABSTRACT FROM AUTHOR]