英语翻译Gadolinium(III) complexes are widely used in magneticres

英语翻译
Gadolinium(III) complexes are widely used in magnetic
resonance imaging (MRI) as water relaxation agents to
improve image contrast.[1–3] Therapeutic gadolinium-containing
agents are also known in which the metal complex
enhances tumor response to chemotherapeutics such as
cisplatin,[4] or,more commonly,acts as a radiosensitizer in
the treatment of diseases,such as cancer.[5–11] Gadolinium may
also play an important role in therapeutic techniques,such as
synchrotron stereotactic radiotherapy (SSR),in which the
selective delivery of gadolinium to the cell nucleus would
significantly enhance the efficacy of the treatment.[6] Indeed,
De Stasio and co-workers have demonstrated that motexafin-
Gd,a gadolinium(III) complex of the pentadentate texaphyrin
ligand,was accumulated by approximately 90% of
glioblastoma cell nuclei in vitro,and its potential exploitation
as a GdSSR agent is warranted.[6]
In recent years,gadolinium complexes have also been
explored as potential agents in an experimental anti-cancer
treatment known as gadolinium neutron-capture therapy
(GdNCT),[12–14] which is closely related to the well-established
boron neutron-capture therapy (BNCT).[15–17] GdNCTutilizes
the non-radioactive 157Gd isotope (natural abundance 15.7%)
in a highly effective thermal neutron-capture reaction to
destroy tumor cells.157Gd possesses the largest effective
nuclear cross-section of all naturally-occurring elements
(2.55 \2 105 barns); this value is approximately 66 times greater
than that of the 10B nucleus.157Gd undergoes neutron capture
to give the products of internal conversion,accompanying
Auger and Coster–Kronig (ACK) electron emission and
7.94 MeVof energy.However,the very limited range of ACK
electrons means that the gadolinium complex must be
localized in close proximity to critical cellular components,
such as the cell nucleus,if the neutron capture reaction is to be
exploited effectively.The use of gadolinium(III) complexes as
potential GdNCT delivery agents to brain tumors has been
described,[18–21] although the feasibility of using archetypal
MRI agents such as Gd-DTPA (DTPA=diethylenetriaminepentaacetic
acid) in a clinical context for GdNCT is considered
unlikely owing to the limited number of tumor-cell
nuclei that have been shown to incorporate gadolinium.
Indeed,the number of gadolinium compounds reported to
date that have a capacity to aggregate selectively in tumor-cell
nuclei,for example,is very limited,[6] and the search for new
types of gadolinium(III) complexes with high nuclear affinity
has recently been proposed.[2

钆（Gd）（III）络合物广泛用于磁共振成像（MRI）中作为水松弛剂来改善图像的反差[1-3].治疗用含Gd药剂也是众所周知的,其中,金属络合物提高了肿瘤对化学疗法（如顺氯氨铂[4]）的响应,或者说更通常地,在疾病（如癌症）的治疗中起到放射致敏剂的作用[5-11].Gd也可以在治疗性技术,例如同步辐射立体定向放射治疗（SSR）中起重要的作用,其中,Gd的选择性提供到细胞核会明显提高治疗的功效[6].确实,De Stasio和他的同事们已经实验证明了,motexafin-Gd（莫特沙芬钆）,一种pentadentate texaphyrin配体的Gd (III)络合物被大约90%的恶性胶质瘤细胞核在体外积聚,而它作为GdSSR药剂的潜在开发是有充分根据的[6].
近年来,Gd络合物作为潜在的药剂在实验的抗癌治疗中也得到了开发,这就是众所周知的Gd中子俘获疗法（GdNCT）[12-14],这与早已建立的硼中子俘获疗法（BNCT）[15-17]密切相关.GdNCT在高度有效的热中子俘获反应中利用非放射性的157Gd同位素（天然丰度15.7%）来破坏肿瘤细胞.157Gd具有所有自然发生的元素中最大的有效核横截面（2.55×105靶恩）；此值大约是10B（硼）原子核有效核横截面的66倍.157Gd经受中子俘获,提供内部转换的产物,伴随着Auger（俄歇）和Coster-Kronig (ACK)电子发射以及7.94 MeV的能量.可是,ACK电子非常有限的范围意味着,如果中子俘获反应要有效得到探索的话,Gd络合物必须定位在非常临近临界细胞组分,例如细胞核的地方.采用Gd(III)络合物作为潜在的、向脑部肿瘤的GdNCT提供药剂已经加以描述[18-21],不过在GdNCT的临床应用中采用原始模型的MRI药剂（比如Gd-DTPA(DTPA=二亚乙基三胺五乙酸)）的可行性被认为是不可能的,因为业已证明结合进Gd的肿瘤细胞核的数目有限.确实,迄今报道的,能够在肿瘤细胞核中选择性地聚集的Gd化合物的数目非常有限[6],而对于新的具有高细胞核亲和力的Gd (III)络合物类型的探索已经提出[21].