量子
Quantum
Supervised learning with quantum-enhanced feature spaces
带有量子增强特征空间的监督学习
▲ 作者：Vojtěch Havlí?ek, Antonio D. Córcoles, Kristan Temme, et al
▲链接：
https://www.nature.com/articles/s41586-019-0980-2
▲ 摘要：
量子算法实现的计算加速的一个核心要素是通过可控纠缠和干涉利用指数级大小的量子态空间。
这里，我们提出并在超导处理器上实验实现了两种量子算法。这两种方法的一个关键组成部分是利用量子态空间作为特征空间。一种方法是量子变分分类器，它使用一个变分量子电路对数据进行分类，其方法类似于传统的支持向量机方法。另一种方法是量子核估计器，它对量子计算机上的核函数进行估计，并对经典的支持向量机进行优化。
这两种方法为探索带噪声的中等规模量子计算机在机器学习中的应用提供了工具。
▲ Abstract
A core element in the computational speed-ups enabled by quantum algorithms is the exploitation of an exponentially large quantum state space through controllable entanglement and interference. Here we propose and experimentally implement two quantum algorithms on a superconducting processor. A key component in both methods is the use of the quantum state space as feature space. One method, the quantum variational classifier (SVM), uses a variational quantum circuit to classify the data in a way similar to the method of conventional support vector machines. The other method, a quantum kernel estimator, estimates the kernel function on the quantum computer and optimizes a classical SVM. The two methods provide tools for exploring the applications of noisy intermediate-scale quantum computers to machine learning.
Thermodynamic signatures of quantum criticality in cuprate superconductors
铜氧化物超导体中量子临界性的热力学特征
▲作者：B. Michon, C. Girod, S. Badoux, J. Ka?mar?ík, et al
▲链接：
https://www.nature.com/articles/s41586-019-0932-x
▲ 摘要：
铜氧化物（氧化铜）超导体的3个中心现象通过一个共同的掺杂水平p*联系在一起——在这个掺杂水平上，神秘的赝能隙相位终止，电阻率呈现出反常的对温度的线性依赖，同时超导相在相图中形成一个圆顶形区域。
这里，我们测量了铜氧化物Eu-LSCO和Nd-LSCO在低温下、大到足以抑制超导电性的磁场中以及包括p*在内的广泛掺杂范围内的比热容。
作为掺杂的函数，我们发现Cel/T在p*处有很强的峰值（Cel是对比热容的电子贡献），并且在温度T趋于零时表现出log(1/T)依赖关系。这些是量子临界点的经典热力学特征，正如在重费米子和铁基超导体的反铁磁相结束时所观察到的那样。
▲ Abstract
The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*—at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (whereCel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point, as observed in heavy-fermion and iron-based superconductors at the point where their antiferromagnetic phase comes to an end.
生物学
Biology
Proteomics identifies new therapeutic targets of early-stage hepatocellular carcinoma
蛋白质组学辨别出早期肝细胞性肝癌新的治疗靶点
▲作者：Ying Jiang, Aihua Sun, Yang Zhao, Wantao Ying, et al
▲链接：
https://www.nature.com/articles/s41586-019-0987-8
▲ 摘要：
肝细胞性肝癌是全球第三大癌症致死原因。乙型肝炎病毒感染是导致这种肝癌的主要危险因素之一，尤其是在东亚地区。
在此，我们利用蛋白质组学和磷酸蛋白质组学的方法，对110对同乙肝病毒感染相关的临床早期肝细胞性肝癌的肿瘤和非肿瘤组织进行了分析。我们的定量蛋白组学数据突出了早期肝细胞性肝癌的异质性：我们使用这一方法将研究队列分为S-I、S-II和S-III亚型，每一亚型都有不同的临床结果。
S-III的特点是胆固醇稳态紊乱，总体生存率最低，一线手术后预后不良的风险最大。胆固醇O -酰基转移酶1（SOAT1）的高表达是S-III亚型特有的特征，它的下调可改变细胞胆固醇的分布，有效抑制肝细胞性肝癌的增殖和迁移。
▲ Abstract
Hepatocellular carcinoma is the third leading cause of deaths from cancer worldwide. Infection with the hepatitis B virus is one of the leading risk factors for developing hepatocellular carcinoma, particularly in East Asia. Here, using proteomic and phospho-proteomic profiling, we characterize 110 paired tumour and non-tumour tissues of clinical early-stage hepatocellular carcinoma related to hepatitis B virus infection. Our quantitative proteomic data highlight heterogeneity in early-stage hepatocellular carcinoma: we used this to stratify the cohort into the subtypes S-I, S-II and S-III, each of which has a different clinical outcome. S-III, which is characterized by disrupted cholesterol homeostasis, is associated with the lowest overall rate of survival and the greatest risk of a poor prognosis after first-line surgery. The knockdown of sterol O-acyltransferase 1 (SOAT1)—high expression of which is a signature specific to the S-III subtype—alters the distribution of cellular cholesterol, and effectively suppresses the proliferation and migration of hepatocellular carcinoma.
Bacterial cGAS-like enzymes synthesize diverse nucleotide signals
细菌cGAS样酶合成多种核苷酸信号
▲作者：Aaron T. Whiteley, James B. Eaglesham, Carina C. de Oliveira Mann, et al
▲链接：
https://www.nature.com/articles/s41586-019-0953-5
▲ 摘要：
环二核苷酸（CDNs）作为核苷酸的第二信使，在细菌的稳态和毒力中起着核心作用。当细菌的CDNs被动物细胞中的模式识别受体检测到时，它们也会在感染过程中引发免疫反应。
这里，我们对细菌信号核苷酸进行了系统的生物化学筛选，发现了一个大的cGAS/ dncv样核苷酸转移酶（CD-NTases）家族。它们同时利用嘌呤和嘧啶核苷酸合成多种CDNs。
一系列的晶体结构使CD-NTases成为一个结构保守的家族，并且揭示了酶活性位点盖中直接指导嘌呤或嘧啶选择的关键接触点。CD-NTase产品不仅仅限于CDNs，还包括一类意想不到的环三核苷酸化合物。对CD-NTase信号核苷酸进行的生化和细胞分析表明，这些环状二核苷酸和三核苷酸激活不同的宿主受体，从而可能调节病原体和共生微生物群与其动物和植物宿主之间的相互作用。
▲ Abstract
Cyclic dinucleotides (CDNs) have central roles in bacterial homeostasis and virulence by acting as nucleotide second messengers. Bacterial CDNs also elicit immune responses during infection when they are detected by pattern-recognition receptors in animal cells. Here we perform a systematic biochemical screen for bacterial signalling nucleotides and discover a large family of cGAS/DncV-like nucleotidyltransferases (CD-NTases) that use both purine and pyrimidine nucleotides to synthesize a diverse range of CDNs. A series of crystal structures establish CD-NTases as a structurally conserved family and reveal key contacts in the enzyme active-site lid that direct purine or pyrimidine selection. CD-NTase products are not restricted to CDNs and also include an unexpected class of cyclic trinucleotide compounds. Biochemical and cellular analyses of CD-NTase signalling nucleotides demonstrate that these cyclic di- and trinucleotides activate distinct host receptors and thus may modulate the interaction of both pathogens and commensal microbiota with their animal and plant hosts.
天文学
Astronomy
A distance to the Large Magellanic Cloud that is precise to one per cent
到大麦哲伦云的距离精确度达到1%
▲作者：G. Pietrzyński, D. Graczyk, A. Gallenne, W. Gieren, et al
▲链接：
https://www.nature.com/articles/s41586-019-0999-4
▲ 摘要：
在精密宇宙学的时代，以1%或更高的精确度从经验上确定哈勃常数至关重要。目前，关于该常数的不确定性主要由造父变星周期光度关系（也称为莱维特定律）校准的不确定性决定。大麦哲伦星云传统上被认为是校准造父变星周期光度关系的最佳星系，并因此成为宇宙距离尺度的最佳锚点。
这里，我们报告了一种表面亮度—颜色关系的校准，其精确度为0.8%。我们基于20个重叠的双星系统，利用这种校准确定了与大麦哲伦云的几何距离，其精确度为1%。最终距离为49.59±0.09（统计）±0.54（系统）千帕秒。
▲ Abstract
In the era of precision cosmology, it is essential to determine the Hubble constant empirically with an accuracy of one per cent or better. At present, the uncertainty on this constant is dominated by the uncertainty in the calibration of the Cepheid period–luminosity relationship (also known as the Leavitt law). The Large Magellanic Cloud has traditionally served as the best galaxy with which to calibrate Cepheid period–luminosity relations, and as a result has become the best anchor point for the cosmic distance scale. Here we report a calibration of the surface brightness–colour relation with a precision of 0.8 per cent. We use this calibration to determine a geometrical distance to the Large Magellanic Cloud that is precise to 1 per cent based on 20 eclipsing binary systems. The final distance is 49.59 ± 0.09 (statistical) ± 0.54 (systematic) kiloparsecs.
健康
Health
Exposing Anopheles mosquitoes to antimalarials blocks Plasmodium parasite transmission
使按蚊暴露于抗疟药物可阻断疟原虫的传播
▲作者：Douglas G. Paton, Lauren M. Childs, Maurice A. Itoe, et al
▲链接：
https://www.nature.com/articles/s41586-019-0973-1
▲ 摘要：
按蚊叮咬会传播恶性疟原虫，从而引发每年导致数十万人死亡的疟疾。这里，我们证实，当雌性冈比亚疟蚊从处理过的表面（模拟与蚊帐接触的条件）吸收低浓度的特定抗疟药物时，恶性疟原虫的发展可被迅速、完全阻断。
蚊子在感染恶性疟原虫之前或之后不久接触阿托伐醌，会导致中肠内寄生虫的发育完全停滞，并防止感染的传播。其他细胞色素b抑制剂也有类似的阻断作用，说明寄生虫线粒体功能是杀灭寄生虫的合适靶点。
▲ Abstract
Bites of Anopheles mosquitoes transmit Plasmodium falciparum parasites that cause malaria, which kills hundreds of thousands of people every year. Here we show that the development of P. falciparum can be rapidly and completely blocked when female Anopheles gambiae mosquitoes take up low concentrations of specific antimalarials from treated surfaces—conditions that simulate contact with a bed net. Mosquito exposure to atovaquone before, or shortly after, P. falciparum infection causes full parasite arrest in the midgut, and prevents transmission of infection. Similar transmission-blocking effects are achieved using other cytochrome b inhibitors, which demonstrates that parasite mitochondrial function is a suitable target for killing parasites.
量子
Quantum
Supervised learning with quantum-enhanced feature spaces
带有量子增强特征空间的监督学习
▲ 作者：Vojtěch Havlí?ek, Antonio D. Córcoles, Kristan Temme, et al
▲链接：
https://www.nature.com/articles/s41586-019-0980-2
▲ 摘要：
量子算法实现的计算加速的一个核心要素是通过可控纠缠和干涉利用指数级大小的量子态空间。
这里，我们提出并在超导处理器上实验实现了两种量子算法。这两种方法的一个关键组成部分是利用量子态空间作为特征空间。一种方法是量子变分分类器，它使用一个变分量子电路对数据进行分类，其方法类似于传统的支持向量机方法。另一种方法是量子核估计器，它对量子计算机上的核函数进行估计，并对经典的支持向量机进行优化。
这两种方法为探索带噪声的中等规模量子计算机在机器学习中的应用提供了工具。
▲ Abstract
A core element in the computational speed-ups enabled by quantum algorithms is the exploitation of an exponentially large quantum state space through controllable entanglement and interference. Here we propose and experimentally implement two quantum algorithms on a superconducting processor. A key component in both methods is the use of the quantum state space as feature space. One method, the quantum variational classifier (SVM), uses a variational quantum circuit to classify the data in a way similar to the method of conventional support vector machines. The other method, a quantum kernel estimator, estimates the kernel function on the quantum computer and optimizes a classical SVM. The two methods provide tools for exploring the applications of noisy intermediate-scale quantum computers to machine learning.
Thermodynamic signatures of quantum criticality in cuprate superconductors
铜氧化物超导体中量子临界性的热力学特征
▲作者：B. Michon, C. Girod, S. Badoux, J. Ka?mar?ík, et al
▲链接：
https://www.nature.com/articles/s41586-019-0932-x
▲ 摘要：
铜氧化物（氧化铜）超导体的3个中心现象通过一个共同的掺杂水平p*联系在一起——在这个掺杂水平上，神秘的赝能隙相位终止，电阻率呈现出反常的对温度的线性依赖，同时超导相在相图中形成一个圆顶形区域。
这里，我们测量了铜氧化物Eu-LSCO和Nd-LSCO在低温下、大到足以抑制超导电性的磁场中以及包括p*在内的广泛掺杂范围内的比热容。
作为掺杂的函数，我们发现Cel/T在p*处有很强的峰值（Cel是对比热容的电子贡献），并且在温度T趋于零时表现出log(1/T)依赖关系。这些是量子临界点的经典热力学特征，正如在重费米子和铁基超导体的反铁磁相结束时所观察到的那样。
▲ Abstract
The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*—at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (whereCel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point, as observed in heavy-fermion and iron-based superconductors at the point where their antiferromagnetic phase comes to an end.
生物学
Biology
Proteomics identifies new therapeutic targets of early-stage hepatocellular carcinoma
蛋白质组学辨别出早期肝细胞性肝癌新的治疗靶点
▲作者：Ying Jiang, Aihua Sun, Yang Zhao, Wantao Ying, et al
▲链接：
https://www.nature.com/articles/s41586-019-0987-8
▲ 摘要：
肝细胞性肝癌是全球第三大癌症致死原因。乙型肝炎病毒感染是导致这种肝癌的主要危险因素之一，尤其是在东亚地区。
在此，我们利用蛋白质组学和磷酸蛋白质组学的方法，对110对同乙肝病毒感染相关的临床早期肝细胞性肝癌的肿瘤和非肿瘤组织进行了分析。我们的定量蛋白组学数据突出了早期肝细胞性肝癌的异质性：我们使用这一方法将研究队列分为S-I、S-II和S-III亚型，每一亚型都有不同的临床结果。
S-III的特点是胆固醇稳态紊乱，总体生存率最低，一线手术后预后不良的风险最大。胆固醇O -酰基转移酶1（SOAT1）的高表达是S-III亚型特有的特征，它的下调可改变细胞胆固醇的分布，有效抑制肝细胞性肝癌的增殖和迁移。
▲ Abstract
Hepatocellular carcinoma is the third leading cause of deaths from cancer worldwide. Infection with the hepatitis B virus is one of the leading risk factors for developing hepatocellular carcinoma, particularly in East Asia. Here, using proteomic and phospho-proteomic profiling, we characterize 110 paired tumour and non-tumour tissues of clinical early-stage hepatocellular carcinoma related to hepatitis B virus infection. Our quantitative proteomic data highlight heterogeneity in early-stage hepatocellular carcinoma: we used this to stratify the cohort into the subtypes S-I, S-II and S-III, each of which has a different clinical outcome. S-III, which is characterized by disrupted cholesterol homeostasis, is associated with the lowest overall rate of survival and the greatest risk of a poor prognosis after first-line surgery. The knockdown of sterol O-acyltransferase 1 (SOAT1)—high expression of which is a signature specific to the S-III subtype—alters the distribution of cellular cholesterol, and effectively suppresses the proliferation and migration of hepatocellular carcinoma.
Bacterial cGAS-like enzymes synthesize diverse nucleotide signals
细菌cGAS样酶合成多种核苷酸信号
▲作者：Aaron T. Whiteley, James B. Eaglesham, Carina C. de Oliveira Mann, et al
▲链接：
https://www.nature.com/articles/s41586-019-0953-5
▲ 摘要：
环二核苷酸（CDNs）作为核苷酸的第二信使，在细菌的稳态和毒力中起着核心作用。当细菌的CDNs被动物细胞中的模式识别受体检测到时，它们也会在感染过程中引发免疫反应。
这里，我们对细菌信号核苷酸进行了系统的生物化学筛选，发现了一个大的cGAS/ dncv样核苷酸转移酶（CD-NTases）家族。它们同时利用嘌呤和嘧啶核苷酸合成多种CDNs。
一系列的晶体结构使CD-NTases成为一个结构保守的家族，并且揭示了酶活性位点盖中直接指导嘌呤或嘧啶选择的关键接触点。CD-NTase产品不仅仅限于CDNs，还包括一类意想不到的环三核苷酸化合物。对CD-NTase信号核苷酸进行的生化和细胞分析表明，这些环状二核苷酸和三核苷酸激活不同的宿主受体，从而可能调节病原体和共生微生物群与其动物和植物宿主之间的相互作用。
▲ Abstract
Cyclic dinucleotides (CDNs) have central roles in bacterial homeostasis and virulence by acting as nucleotide second messengers. Bacterial CDNs also elicit immune responses during infection when they are detected by pattern-recognition receptors in animal cells. Here we perform a systematic biochemical screen for bacterial signalling nucleotides and discover a large family of cGAS/DncV-like nucleotidyltransferases (CD-NTases) that use both purine and pyrimidine nucleotides to synthesize a diverse range of CDNs. A series of crystal structures establish CD-NTases as a structurally conserved family and reveal key contacts in the enzyme active-site lid that direct purine or pyrimidine selection. CD-NTase products are not restricted to CDNs and also include an unexpected class of cyclic trinucleotide compounds. Biochemical and cellular analyses of CD-NTase signalling nucleotides demonstrate that these cyclic di- and trinucleotides activate distinct host receptors and thus may modulate the interaction of both pathogens and commensal microbiota with their animal and plant hosts.
天文学
Astronomy
A distance to the Large Magellanic Cloud that is precise to one per cent
到大麦哲伦云的距离精确度达到1%
▲作者：G. Pietrzyński, D. Graczyk, A. Gallenne, W. Gieren, et al
▲链接：
https://www.nature.com/articles/s41586-019-0999-4
▲ 摘要：
在精密宇宙学的时代，以1%或更高的精确度从经验上确定哈勃常数至关重要。目前，关于该常数的不确定性主要由造父变星周期光度关系（也称为莱维特定律）校准的不确定性决定。大麦哲伦星云传统上被认为是校准造父变星周期光度关系的最佳星系，并因此成为宇宙距离尺度的最佳锚点。
这里，我们报告了一种表面亮度—颜色关系的校准，其精确度为0.8%。我们基于20个重叠的双星系统，利用这种校准确定了与大麦哲伦云的几何距离，其精确度为1%。最终距离为49.59±0.09（统计）±0.54（系统）千帕秒。
▲ Abstract
In the era of precision cosmology, it is essential to determine the Hubble constant empirically with an accuracy of one per cent or better. At present, the uncertainty on this constant is dominated by the uncertainty in the calibration of the Cepheid period–luminosity relationship (also known as the Leavitt law). The Large Magellanic Cloud has traditionally served as the best galaxy with which to calibrate Cepheid period–luminosity relations, and as a result has become the best anchor point for the cosmic distance scale. Here we report a calibration of the surface brightness–colour relation with a precision of 0.8 per cent. We use this calibration to determine a geometrical distance to the Large Magellanic Cloud that is precise to 1 per cent based on 20 eclipsing binary systems. The final distance is 49.59 ± 0.09 (statistical) ± 0.54 (systematic) kiloparsecs.
健康
Health
Exposing Anopheles mosquitoes to antimalarials blocks Plasmodium parasite transmission
使按蚊暴露于抗疟药物可阻断疟原虫的传播
▲作者：Douglas G. Paton, Lauren M. Childs, Maurice A. Itoe, et al
▲链接：
https://www.nature.com/articles/s41586-019-0973-1
▲ 摘要：
按蚊叮咬会传播恶性疟原虫，从而引发每年导致数十万人死亡的疟疾。这里，我们证实，当雌性冈比亚疟蚊从处理过的表面（模拟与蚊帐接触的条件）吸收低浓度的特定抗疟药物时，恶性疟原虫的发展可被迅速、完全阻断。
蚊子在感染恶性疟原虫之前或之后不久接触阿托伐醌，会导致中肠内寄生虫的发育完全停滞，并防止感染的传播。其他细胞色素b抑制剂也有类似的阻断作用，说明寄生虫线粒体功能是杀灭寄生虫的合适靶点。
▲ Abstract
Bites of Anopheles mosquitoes transmit Plasmodium falciparum parasites that cause malaria, which kills hundreds of thousands of people every year. Here we show that the development of P. falciparum can be rapidly and completely blocked when female Anopheles gambiae mosquitoes take up low concentrations of specific antimalarials from treated surfaces—conditions that simulate contact with a bed net. Mosquito exposure to atovaquone before, or shortly after, P. falciparum infection causes full parasite arrest in the midgut, and prevents transmission of infection. Similar transmission-blocking effects are achieved using other cytochrome b inhibitors, which demonstrates that parasite mitochondrial function is a suitable target for killing parasites.
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