Science12月最新重大研究发表（中英文版）
来源: 【Science】 阅读次数: 【2759】 发布日期: 【2018-12-18】
Although a range of
materials can now be fabricated using additive manufacturing techniques, these
usually involve assembly of a series of stacked layers, which restricts
three-dimensional (3D) geometry. Oran et al. developed a method to print
a range of materials, including metals and semiconductors, inside a gel
scaffold (see the Perspective by Long and Williams). When the hydrogels were
dehydrated, they shrunk 10-fold, which pushed the feature sizes down to the
nanoscale. —MSL Science, this issue p. 1281;
see also p. 1244
Use of a gel
scaffold allows for more-complex 3D printing
尽管现在可以使用增材制造技术制造一系列材料，但这通常涉及到一系列堆叠层的组装，因此限制了三维几何形状。Oran等人开发了一种方法，可以在凝胶支架内打印金属和半导体等一系列材料(参见Long和Williams的前瞻性研究)。水凝胶脱水时会收缩10倍，这会将特征尺寸压缩到纳米级。（《科学》第362卷，6420期，1281,1244页）
凝胶支架的使用使得3D打印更加复杂
Galaxies are
nonuniformly distributed in the Universe, forming a cosmic web of filaments and
clusters. Filaments occupy about 5% of the volume of the Universe but contain
about a third of the galaxies, which grow by merging. Mesa et al. identified
pairs of neighboring galaxies embedded within filaments. They found that the
orientation of the pairs preferentially align with the axes of the surrounding
filaments, with the effect being more pronounced for elliptical galaxies than
for spirals. Because galaxy spins are known to follow the filament direction,
this implies that major merger events have a preferred orientation in this
environment. —KTS Astron. Astrophys. 619, A24 (2018).
星系在宇宙中是不均匀分布的，形成了由丝状结构和星系团组成的宇宙网络。虽然丝状结构仅占宇宙体积的5%左右，但包含了约三分之一的星系，这些星系通过合并而成长。Mesa等人发现了嵌在丝状结构中的相邻星系对。他们发现，星系对的方向优先与周围的丝状结构轴对齐，这种效应在椭圆星系中比在螺旋星系中更为明显。因为星系自旋遵循丝状结构方向，这意味着重大的合并事件在这个环境中有优先方向。（《天文学与天体物理学》， 第619卷，A24）
ENZYMOLOGY 酶学
Metal-bound peptides can catalyze simple reactions such
as ester hydrolysis and may have been the starting point for the evolution of
modern enzymes. Studer et al. selected
progressively more-proficient variants of a small protein derived from a computationally
designed zinc-binding peptide. The resulting enzyme could perform the trained
reaction at rates typical for naturally evolved enzymes and serendipitously
developed a strong preference for a single enantiomer of the substrate. A
structure of the final catalyst highlights how small, progressive changes can
remodel both catalytic residues and protein architecture in unpredictable ways.
—MAF Science, this issue p.
1285
金属结合肽可以催化酯的水解等简单反应，因此可能是现代酶进化的起点。Studer等人从计算设计的锌结合肽中逐步选择了一种更加成熟的小蛋白变体。由此产生的酶能够以自然进化酶的典型速率进行训练反应，并且意外地，它对底物的单一对映异构体可产生强烈偏好。最终催化剂的结构强调了微小的渐进变化如何以不可预知的方式重塑催化残留物和蛋白质结构。（《科学》第362卷，6420期，1285页）
ELECTROCATALYSIS 电催化作用
Platinum (Pt)–group metals, which are scarce and
expensive, are used for the demanding oxygen reduction reaction (ORR) in
hydrogen fuel cells. One competing approach for reducing their use is to create
nanoparticles with earth-abundant metals to increase their activity and surface
area; another is to replace them with metals such as cobalt (Co) in carbide or
nitride sites. Chong et al. thermally
activated a Co metal-organic framework compound to create ORR-active Co sites
and then grew PtCo alloy nanoparticles on this substrate. The resulting
catalyst had high activity and durability, despite its relatively low Pt
content. —PDS Science, this issue p.
1276
稀有贵重金属——铂系金属，常用于氢燃料电池的氧还原反应。减少其使用量的一种方法是用地球上丰富的金属制造纳米颗粒，以增加其活性和表面积；另一种方法是用碳化物或氮化物位点的钴等金属来代替它们。Chong等人通过热激活钴金属—有机骨架化合物创建了ORR活性钴位点，然后在该基底上生长PtCo铂钴合金纳米颗粒。尽管铂的含量相对较低，但其活性和耐久性较高。（《科学》第362卷，6420期，1276页）
ARCHAEOLOGY 考古学
Evidence for the earliest stone tools produced by human
ancestors (from ~2.6 million years ago) has hitherto come from East Africa.
Sahnouni et al. report the
discovery of Oldowan stone artifacts and associated cutmarks on fossil bones
excavated in Algeria, with the earliest dated to 2.4 million years ago. Thus,
hominins inhabited the Mediterranean fringe in North Africa earlier than
commonly believed. Furthermore, either stone tool manufacture and use dispersed
early from East Africa or stone tool manufacture and use originated in both
North and East Africa. —AMS Science, this issue p.
1297
迄今为止，人类祖先（约260万年前）制造的最古老石器有证据显示来自于东非。Sahnouni等报道在阿尔及利亚出土了奥尔德沃（Oldowan）石器，并在相关骨骼化石上发现了刻痕，最早可追溯到240万年前。因此，人类在北非地中海沿岸的居住时间比一般认为的要早。此外，结果还显示石器的制造和使用很早就从东非传播开来，或者起源于北非和东非。（《科学》第362卷，6420期，1297页）
PLANT SCIENCE 植物学
The parasitic plant Striga hermonthica causes extensive
crop losses, particularly in Africa. Strigolactone hormones can be used to
initiate germination of Striga seeds when no
host crop is present, which causes the nascent Striga plants to die. Unfortunately, strigolactones are also
used by crop plants to establish beneficial mutualisms. Uraguchi et al.
developed a hybrid molecule that can initiate Striga germination without
interfering with strigolactone dependent events in the host (see the
Perspective by Bouwmeester). The compound has the potential to diversify routes
toward protecting fields from Striga infestation. —PJH Science, this issue p. 1301; see also p. 1248
寄生植物黄独脚金会造成大面积的作物减产，这一情况在非洲尤为严重。植物激素——独角金内酯可以在没有宿主作物的情况下使独脚金属种子发芽，使新生独脚金属植株死亡。不幸的是，独角金内酯也被作物植物用来建立有益的共栖关系。Uraguchi等人开发了一种能够启动独脚金属植株萌发而不干扰宿主中独角金内酯依赖事件的杂交分子(见Bouwmeester的前瞻性研究)。该化合物可丰富保护农田免受独脚金毒草侵害的途径。（《科学》第362卷，6420期，1301,1248页）
IMMUNOGENOMICS 免疫遗传学
Immunoglobulin E (IgE) antibodies play a central role in
immune responses against helminth and protozoan parasites; however, they also
contribute to allergies. IgE antibodies (and the B cells generating them) are
rare and thus poorly characterized. Croote et al. performed single-cell RNA sequencing of peripheral
blood B cells from patients with peanut allergies and delineated each cell’s
gene expression, splice variants, and antibody sequences (see the Perspective
by Gould and Ramadani). Unlike other isotypes, circulating IgE B cells were
mostly immature plasmablasts. Surprisingly, certain IgE antibodies manifested
identical gene rearrangements in unrelated individuals. These IgE antibodies
showed high affinity and unexpected cross-reactivity to peanut allergens. —STS Science, this issue p. 1306; see also p. 1247
免疫球蛋白E（IgE）抗体在对抗寄生虫和原生动物寄生虫的免疫应答中起着核心作用；然而，它们也会引起过敏。IgE抗体（以及产生IgE抗体的B细胞）很少见，因此目前对其表征严重不足。Croote等人对花生过敏患者外周血B细胞进行了单细胞RNA测序，描绘了每个细胞的基因表达、剪接变异和抗体序列（见Gould和Ramadani的前瞻性研究）。与其他亚型不同，循环产生IgE的B细胞多为未成熟质粒。令人惊讶的是，某些IgE抗体在不相关个体中表现出相同的基因重排。这些IgE抗体对花生过敏原具有高亲和力和意想不到的交叉反应性。（《科学》第362卷，6420期，1306,1247页）
MAIZE DOMESTICATION 玉米驯化
Maize originated in what is now central Mexico about 9000
years ago and spread throughout the Americas before European contact. Kistler et al. applied genomic analysis to ancient and extant South
American maize lineages to investigate the genetic changes that accompanied
domestication (see the Perspective by Zeder). The origin of modern maize
cultivars likely involved a “semidomesticated” lineage that moved out of
Mexico. Later improvements then occurred among multiple South American
populations, including those in southwestern Amazonia. —LMZ Science,
this issue p. 1309; see also p. 1246
玉米大约在9000年前起源于现在的墨西哥中部地区，并在欧洲人接触之前就传遍了美洲。Kistler等人将基因组分析应用于古老和现存的南美玉米谱系，以研究驯化过程中伴随的遗传变化（参见Zeder的前瞻性研究）。现代玉米品种的起源很可能与从墨西哥传出的“半驯化”谱系有关。随后，包括亚马逊西南部在内的多个南美群落的玉米得到了改善。（《科学》第362卷，6420期，1309, 1246页）
DIAGNOSTICS 诊断学
Many infectious diseases present with common clinical
symptoms, such as fever, which complicates diagnosis at the point of need.
Sebba et al. used surface-enhanced
Raman scattering (SERS) nanotags to distinguish Ebola virus infections from
Lassa fever and malaria. The no-wash triplex assay workflow adds a small volume
of blood and buffer to dried SERS reagents and delivers a readout within 30
minutes. The assay detected parasite- and virus-specific antigens spiked into
blood, Ebola infections in nonhuman primates, and Ebola and malaria infections
in human blood samples collected from endemic regions during field testing. —CC Sci. Transl. Med. 10, eaat0944 (2018).
许多传染病具有共同的临床症状（如发热），这使得诊断变得非常复杂。Sebba等人使用表面增强拉曼散射（SERS）纳米标记来区分埃博拉病毒感染与拉沙热和疟疾。在免洗三次检测中，在干燥的SERS试剂中添加少量血液和缓冲液，并在30分钟内给出读数。该检测方法检测了进入血液的寄生虫和病毒特异性抗原，非人灵长类动物的埃博拉感染，以及实地检测期间从流行地区采集的人类血液样本中的埃博拉和疟疾感染。（《科学—转化医学》第10卷，0944期）
EDUCATION 教育
Chronic sleep deprivation during adolescence is a growing
problem. In 2017, the Seattle school district became the largest U.S. school
district to delay secondary-school start times by nearly an hour. During this
transition, Dunster et al. used activity
wristwatches to collect quantitative evidence about the effects of a later
school start time. The change increased daily sleep by more than a half hour,
improved the median of students’ grades by 4.5%, and reduced absenteeism and
tardiness. —PJB Sci. Adv. 10.1126/sciadv.aau6200
(2018).
青春期长期睡眠不足已经成为了日益严重的问题。2017年，一些学校将中学生上学时间推迟了近一个小时，其中西雅图学区在这一方面是美国最大的学区。在这一转变过程中，Dunster等人使用活动腕表来收集推迟上学时间的量化效果。这一改变使学生每天的睡眠时间增加了半个多小时，平均成绩提高了4.5%，旷课和迟到现象也有所减少。（《科学进展》）
ORGANIC CHEMISTRY 有机化学
The vastness of the archival chemistry literature is both
a blessing and a curse. The reaction that you’re looking for is probably in
there, provided you take enough time to search for it. Gao et al. trained a neural network model on 10 million known
reactions to speed up this process. Specifically, the model was charged with
predicting a catalyst, reagents, solvents, and temperature to achieve a given
transformation. When tested, the model’s top-10 list of suggestions produced a
close match to actual conditions nearly 70% of the time, with a ±20°C error
margin in temperature. —JSY ACS Cent.
Sci. 4, 1465 (2018).
大量的化学文献是福也是祸。所寻找的反应有可能就在某处，但这需要花费足够多的时间寻找。针对1000万个已知反应，Gao等人训练了神经网络模型，用以加速这一搜寻进程。具体来说，该模型负责预测催化剂、试剂、溶剂和温度，以实现给定的转换。测试时，模型的十大推荐列表会在70&情况下产生与实际情况高度匹配的结果，温度误差在±20°C以内。（《ACS核心科学》第4卷，第1465期）
BIOCHEMISTRY 生物化学
The biosynthetic reactions that power cells often require
unstable or toxic intermediates that must be contained and kept at low
concentrations. One strategy to manage transient species is physical
encapsulation, which can occur at many different size scales. Bernhardsgrütter et
al. characterized a protein cage formed by conjoined catalytic domains,
creating an incredibly small “nanoreactor” for three sequential reactions in a
carbon-fixation pathway. A crystal structure revealed that each domain houses
an independent active site facing the interior compartment. Enzyme kinetics
suggest that the cage can close upon substrate and cofactor binding, preventing
release of reaction intermediates, which have reactive moieties. —MAF Nat.
Chem. Biol. 14, 1127 (2018).
为细胞提供动力的生物合成反应通常需要不稳定或有毒中间产物，这些中间产物必须被控制在低浓度下。瞬态物种的一种管理策略是物理封装，这可以在许多不同尺度下实现。Bernhardsgrütter 等人表征了由结合催化结构域形成的蛋白质笼状物，创造了非常小的“纳米反应器”，用于碳固定路径上的三个顺序反应。晶体结构显示，每个结构域都有独立的面向内部隔室的活性位点。酶动力学研究表明，该笼形物在底物和辅因子结合时就会封闭，阻止了具有活性基团的反应中间体的释放。（《自然-化学生物学》，其14卷，第1127期）
PROTEIN FOLDING 蛋白质折叠
The bacterial enzyme glucosamine-6-phosphate synthase
(GlmS) is essential for synthesis of the cell wall. Its expression is regulated
by a structured messenger RNA (mRNA) element, the glmS riboswitch. Most riboswitches are stabilized in an “on”
conformational state by binding a ligand. In GlmS, however, ligand binding
leads to self-cleavage, and this, in turn, targets the mRNA for degradation.
Savinov and Block used optical tweezers to measure folding dynamics
细菌酶葡萄糖胺-6-磷酸合酶（GlmS）对细胞壁的合成是必不可少的。其表达受结构信使RNA（mRNA）成分，即glmS核糖开关的调控。大多数核糖开关通过与配体结合而稳定在“开启”的构象状态。然而，在GlmS中，配体结合导致自裂，而这反过来又靶向了mRNA的降解。Savinov和Block使用光学镊子测量了折叠动力学。
SUPERCONDUCTIVITY 超导电性
Strong coupling between the spin and orbital degrees of
freedom is crucial in generating the exotic band structure of topological
insulators. The combination of spin-orbit coupling with electronic correlations
could lead to exotic effects; however, these two types of interactions are
rarely found to be strong in the same material. Gotlieb et al. used spin- and angle-resolved photoemission
spectroscopy to map out the spin texture in the cuprate Bi2212. Surprisingly,
they found signatures of spinmomentum locking, not unlike that seen in
topological insulators. Thus, in addition to strong electronic correlations,
this cuprate also has considerable spin-orbit coupling. —JS Science, this issue p. 1271
自旋和轨道自由度的之间的强耦合是拓扑绝缘子奇异带结构产生的关键。自旋-轨道耦合与电子关联的结合可能导致奇异效应；然而，同一种材料中很少发现这两种强相互作用。Gotlieb等利用自旋和角分辨的光发射光谱绘制了铜酸盐Bi2212中的自旋结构。令人惊讶的是，他们发现了自旋动量锁定的特征，这与拓扑绝缘体中看到的类似。因此，除了强电子相关性外，这种铜酸盐还具有相当强的自旋轨道耦合。（《科学》第362卷，6420期，1309, 1271页）
CHEMICAL PHYSICS 化学物理学
During chemical reactions, electrons usually rearrange
more quickly than nuclei. Thus, theorists often adopt an adiabatic framework
that considers vibrational and rotational dynamics within single electronic
states. Near the regime where two electronic states intersect, the dynamics get
more complicated, and a geometric phase factor is introduced to maintain the
simplifying power of the adiabatic treatment. Yuan et al. conducted precise experimental measurements that
validate this approach. They studied the elementary H + HD reaction at energies
just above the intersection of electronic states and observed angular
oscillations in the product-state cross sections that are well reproduced by
simulations that include the geometric phase. —JSY Science, this issue p. 1289
在化学反应中，电子重新排列的速度通常比原子核快。因此，理论家通常采用将单个电子状态下振动和旋转动力学考虑在内的绝热框架。在两个电子态相交的区域附近，动力学变得更加复杂。因此，为了保持绝热处理的简化性，引入了几何相位因子。袁等人开展了精确的实验测量，验证了这种方法。他们研究了能量在电子态交点以上的基本H+HD反应，并观察了产物态截面上的角速度振荡，这些振荡通过包含几何相位的模拟得到了很好的再现。（《科学》第362卷，6420期，1289页）
RADIOCARBON 放射性碳
An accurate, precise record of the carbon-14 (14C)
content of the atmosphere is important for developing chronologies in climate
change, archaeology, and many other disciplines. Cheng et al. provide a record that covers the full range of the 14C
dating method (~54,000 years), using paired measurements of 14C/12C and
thorium-230 (230Th) ages from two stalagmites from Hulu Cave, China. The
advantage of matching absolute 230Th ages and 14C/12C allowed the authors to
fashion a seamless record from a single source with low uncertainties,
particularly in the older sections. —HJS Science, this issue p. 1293
准确、精确地记录大气中碳14（14C）的含量，对于开发与气候变化、考古学和许多其他学科相关的年代学非常重要。利用来自中国葫芦洞两个石笋的14C/12C和钍-230（230Th）成对测年结果，Cheng等人提供了涵盖14C测年（~ 54000年）全范围的记录。230Th测年的绝对年龄和14C/12C测年结果的匹配使作者能够从单一来源创建无缝记录，所得记录不确定性较低，特别是在年代较久远的部分。（《科学》第362卷，6420期，1293页）
ECOLOGY 生态学
Scientific evidence of an ecological and climatic crisis
caused by human actions is compelling, yet humanity is largely continuing on
its current, heavily resource-dependent path. In a Perspective, Crist argues
that the main reasons why humanity is not changing course lie in a
human-centric worldview that discounts the value and needs of nonhuman life. As
a result, placing limits on consumption appears oppressive, and technological
solutions gain supremacy over efforts to reduce human impacts. Resolving the
ecological and climatic crisis will instead require humanity to scale back its
impacts. This will only be possible if we humans reimagine ourselves as part of
the ecosphere. —JFU and SNV Science, this issue p.
1242
现在已经得出了令人信服的证据，显示人类活动造成了生态和气候危机，但人类目前在很大程度上仍在坚持其严重依赖资源的道路。从某种角度来看，Crist认为人类没有改变方向的主要原因在于一种以人为中心的世界观，这种世界观低估了非人类生活的价值和需要。因此，限制资源消费就显得很难以忍受，技术解决方案与减少人类影响的努力相比更为重要。解决生态和气候危机需要人类减少其影响。只有我们人类重新把自己视为成生物圈的一部分，才有可能实现这一点。（《科学》第362卷，6420期，1242页）
NEURODEGENERATION 神经退行性疾病
There has been considerable investment and effort in
developing drugs to slow the progress of Alzheimer’s disease, but clinical
trials have been disappointing. In a Perspective, Golde et al. discuss the problems that have thwarted Alzheimer’s
disease drug development, in particular, treating patients too late during
disease progression. Efforts to improve treatment and prevention strategies
require a mechanism-based approach that also ensures disease progression is
followed accurately during clinical trials. —GKA Science, this issue p. 1250
在开发延缓阿尔茨海默病进展的药物方面已经投入了大量的资金和努力，但临床试验结果一直令人失望。Golde等人在其前瞻性研究中探讨了阻碍阿尔茨海默病药物开发的因素，这其中，尤其以疾病进展中治疗太晚最为重要。改善治疗和预防策略的努力需要一种基于机制的方法，这种方法同时需确保在临床试验期间准确地跟踪疾病进展。（《科学》第362卷，6420期，1250页）
NEUROSCIENCE 神经系统科学
The loss and subsequent return of blood flow in the brain
that occurs with a stroke damages brain tissue and can be lethal or severely
impair cognitive and motor functions. Kim et al. treated rodents with an oligonucleotide mimicking the
microRNA miR-7 either before or within 30 minutes of an experimentally induced
stroke. The approach successfully reduced the amount of brain damage and
improved motor recovery in the animals. The mimic appeared to work by
repressing the expression of the protein a-synuclein, which is associated with neuronal death in
various diseases. —LKF Sci. Signal. 11, eaat4285
(2018).
脑卒中后脑内血流的缺失和随后的恢复会损害脑组织，这是致命的，也可能严重损害患者的认知和运动功能。针对实验诱导中风的啮齿类动物，Kim等人用模拟microRNA miR-7的寡核苷酸在中风之前或中风30分钟内予以治疗。这种方法成功地减少了动物大脑的损伤，改善了运动恢复。这种模拟物似乎是通过抑制蛋白a-synuclein的表达而发挥作用的，这种蛋白与各种疾病中的神经元死亡有关。