98 research outputs found
sj-doc-1-tam-10.1177_17588359231225035 – Supplemental material for Reclassification of RAS/BRAF allele mutations predicts the survival benefit of triplet chemotherapy in metastatic colorectal cancer
No full textSupplemental material, sj-doc-1-tam-10.1177_17588359231225035 for Reclassification of RAS/BRAF allele mutations predicts the survival benefit of triplet chemotherapy in metastatic colorectal cancer by Xiang Zhang, Haizhong Ma, Yinjun He, Wenguang He, Nan Chen, Yandong Li, Weixiang Zhong, Guosheng Wu, Xile Zhou, Hanju Hua, Feng Ye, Hui Cai and Weiqin Jiang in Therapeutic Advances in Medical Oncology</p
sj-doc-2-tam-10.1177_17588359231225035 – Supplemental material for Reclassification of RAS/BRAF allele mutations predicts the survival benefit of triplet chemotherapy in metastatic colorectal cancer
No full textSupplemental material, sj-doc-2-tam-10.1177_17588359231225035 for Reclassification of RAS/BRAF allele mutations predicts the survival benefit of triplet chemotherapy in metastatic colorectal cancer by Xiang Zhang, Haizhong Ma, Yinjun He, Wenguang He, Nan Chen, Yandong Li, Weixiang Zhong, Guosheng Wu, Xile Zhou, Hanju Hua, Feng Ye, Hui Cai and Weiqin Jiang in Therapeutic Advances in Medical Oncology</p
Heck reaction of alkyl halides and α-selective heck reaction of styrenes
No full textMy graduate study has been focused on the development of transition metal-catalyzed reactions, especially Pd-catalyzed coupling reactions. In this thesis, we described two catalytic systems that solved challenging problems in the intermolecular Heck reaction.
In the first part, we disclosed a new catalyst – Pd/dnpf can efficiently catalyze the Heck reaction of aryl and vinyl triflates with aromatic olefins. In most cases, the aryl or vinyl groups insert selectively at α position in >95% purity and the minor isomers can be removed after purification by flash chromatography. We conducted both experimental and computational study to probe the origin of high internal selectivity. The study revealed that the generality and selectivity is attributed to the combination of electronic and steric effects derived from our new ligand – dnpf. The resulting rigid and congested coordination sphere sterically disfavors the terminal insertion. The initial results of aryl bromides unfolded the potential of the newly-developed ligand for more reactions.
In the second part, we disclosed an efficient catalyst – Pd/dppf for the intermolecular Heck reaction of alkyl halides, which is a challenging problem in palladium catalysis. The simple and easily accessible Pd/dppf catalyst showed good reactivity as well as good selectivity. The use of dppf as supporting ligand was crucial for our success in this reaction as other ligands failed to afford the product in a satisfactory yield. It can be applied to a broad spectrum of electrophiles including alkyl iodides, bromides and chlorides. Both primary and secondary alkyl halides bearing functional groups such as esters, amides and nitriles were tolerated in the catalytic system. Concerning the scope of olefins, vinylarenes of steric and electronic perturbations coupled well. We conducted mechanistic study to probe the reaction mechanism and the experimental data suggested that the reaction was initiated by a single electron transfer from Pd(0)-complex to alkyl halides.DOCTOR OF PHILOSOPHY (SPMS
Unsteady Characteristics of Sediment Transport Under Non-harmonic Waves
No full textAbstractSediment transport under waves is one of the key dynamic processes of coastal sediment motion. Previous studies for this issue are mainly based on linear wave theory and quasi-steady simplification. However, waves in real circumstance are always irregular, generally with a certain degree of asymmetry and/or velocity-leaning especially in shallow water. It is envisaged that sediment movement under non-harmonic waves is different from sinusoidal waves. Based on large eddy simulation of turbulent flows in wave boundary layer, a modified method is proposed to calculate sediment transport rate under non-harmonic waves. It is further used to explore the influences of flow acceleration and the phase lead between the free stream velocity and bed shear stress on sediment transport rate in different phases of one wave cycle for forth-leaning. The net transport rate is found to increase with the degree of asymmetry and velocity-leaning index. Both the acceleration and the phase lead have a great influence on average transport rate in each phase
Discontinuation Rates of Tadalafil Alone and in Combination with a-Blockers in the Treatment of Male Lower Urinary Tract Symptoms with or without Coexisting Erectile Dysfunction: A Systematic Review and Meta-Analysis
No full textPurpose. We examined the discontinuation rates of tadalafil alone and in combination with a-blockers (ABs) for the treatment of male lower urinary tract symptoms (LUTS), with or without erectile dysfunction (ED). Materials and Methods. We searched the EMBASE, PubMed, Web of Science, Scopus, Cochrane Library, and ClinicalTrials.gov databases for studies published until May 15, 2022. The discontinuation rates associated with LUTS medications were subsequently analyzed by meta-analysis. Results. Forty-four studies, including 1724 discontinued patients, were included. The combined discontinuation rate was 12.78% (95% confidence interval (CI) 9.89–15.98%), and the discontinuation rates because of adverse events and lack of efficacy were 4.56% (95% CI 3.39–5.90%) and 3.30% (95% CI 1.53–5.72%), respectively. Conclusions. The discontinuation rate of tadalafil alone or in combination with ABs for LUTS with or without ED was relatively low and varied according to the study type. Patients receiving monotherapy or combination therapy were similarly likely to abandon treatment. Treatment with a fixed-dose combination was associated with better persistence than with a free-dose combination. These data may help guide clinicians in selecting drug regimens when making decisions. Factors associated with treatment withdrawal need to be determined through high-quality clinical studies to reduce the drug discontinuation rate, which will ultimately reduce healthcare costs and improve patient outcomes
Editorial: Dams and wetland biodiversity: Impacts and mitigating measures
No full textTo meet energy, water and transportation needs, an incredible amount of dams have been constructed around the world. For example, only in the Yangtze River's watershed of China, over 50,000 dams were built since 1950 (Nilsson et al., 2005; Wu et al., 2019). Dams could contribute to energy and water supply, and flood protection, but they also affect aquatic ecosystems by alteration of hydrologic regime and fragmentation (Barbarossa et al., 2020). While about 50% of the river around the world is currently changed by dam, this percentage is expected to increase to 93% because of the pending construction of about 3,700 major hydropower dams (Grill et al., 2015).
The construction and operation of dams has extensively altered global freshwater wetland ecosystems, which represent biodiversity hotspots around the world and play a crucial part in protection of biodiversity (Wu et al., 2019). Freshwater wetlands cover about 0.8% of Earth's surface, but host an excessively high diversity of species (Barbarossa et al., 2020). Freshwater wetlands provided habitat for about one fifth of species (particularly the endangered and endemic species) and one third of vertebrate species in the world (Wu et al., 2019).
The aim of this Research Topic is to gather the latest research addressing the critical issue of the impact of construction, operation and removal of dams on biodiversity, with a particular focus on mitigating measures. We are convinced that the studies in this field are an essential condition for biodiversity conservation and ecological restoration in freshwater wetlands. This collection of seven papers is our humble contribution to achieve this target.To meet energy, water and transportation needs, an incredible amount of dams have been constructed around the world. For example, only in the Yangtze River's watershed of China, over 50,000 dams were built since 1950 (Nilsson et al., 2005; Wu et al., 2019). Dams could contribute to energy and water supply, and flood protection, but they also affect aquatic ecosystems by alteration of hydrologic regime and fragmentation (Barbarossa et al., 2020). While about 50% of the river around the world is currently changed by dam, this percentage is expected to increase to 93% because of the pending construction of about 3,700 major hydropower dams (Grill et al., 2015).
The construction and operation of dams has extensively altered global freshwater wetland ecosystems, which represent biodiversity hotspots around the world and play a crucial part in protection of biodiversity (Wu et al., 2019). Freshwater wetlands cover about 0.8% of Earth's surface, but host an excessively high diversity of species (Barbarossa et al., 2020). Freshwater wetlands provided habitat for about one fifth of species (particularly the endangered and endemic species) and one third of vertebrate species in the world (Wu et al., 2019).
The aim of this Research Topic is to gather the latest research addressing the critical issue of the impact of construction, operation and removal of dams on biodiversity, with a particular focus on mitigating measures. We are convinced that the studies in this field are an essential condition for biodiversity conservation and ecological restoration in freshwater wetlands. This collection of seven papers is our humble contribution to achieve this target.HW was financially supported by the Natural Science Foundation of Hunan Province (2021JJ40601) and the Scientific Research Foundation of Hunan Provincial Education Department (20B005).HW was financially supported by the Natural Science Foundation of Hunan Province (2021JJ40601) and the Scientific Research Foundation of Hunan Provincial Education Department (20B005)
Observation of Sediments Transport in Three Georges Reservoir during Middle and Small Flood Operation
No full textGeneral suzuki coupling of heteroaryl bromides by using Tri-tert-butylphosphine as a supporting ligand
No full textA general procedure for the fast Suzuki coupling of major families of heteroaryl bromides was realized by using Pd(OAc)2/PtBu3 as the catalyst. Many couplings were finished within minutes at room temperature in n-butanol. Different from previous studies, three typical heteroaryl bromides were systematically examined in couplings of various heteroaryl and aryl boronic acids
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