Pyrrole-Protected beta-Aminoalkylzinc Reagents for the Enantioselective Synthesis of Amino-Derivatives

Chiral beta-aminoalkylzinc halides were prepared starting from optically pure commercial beta-amino-alcohols. These amino-alcohols were converted to the correspondingN-pyrrolyl-protected alkyl iodides which undergo a zinc insertion in the presence of LiCl (THF, 25 degrees C, 10-90 min). Subsequent Negishi cross-coupling or acylation reactions with acid chlorides produced amino-derivatives with retention of chirality. Diastereoselective CBS-reductions of some preparedN-pyrrolyl-ketones provided 1,3-subsitutedN-pyrrolyl-alcohols with high diastereoselectivity. Additionally, a deprotection procedure involving an ozonolysis allowed the conversion of the pyrrole-ring into a formamide without loss of optical purity

(Z)-Isobutyl 2-benzamido-3-(4-chloro­phen­yl)acrylate

The title compound, C20H20ClNO3, is a α-amino acid derivative which displays a Z configuration about the C=C double bond. The dihedral angle betwen the aromatic rings is 87.75 (12)°. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯N hydrogen bond. In the crystal structure, centrosymmetrically related mol­ecules inter­act through inter­molecular C—H⋯O hydrogen-bond inter­actions, forming dimers. The dimers are further linked into chains parallel to the a axis by N—H⋯O hydrogen bonds. The methyl groups of the isopropyl group are disordered over two positions with occupancy factors of 0.5

(2,4-Dichloro­phen­yl)(diphenyl­phosphor­yl)methanol

In the title compound, C19H15Cl2O2P, the dihedral angle between the mean planes of the phenyl rings bonded to the P atom is 75.4 (1)°. In the crystal, mol­ecules are linked into chains running along the a axis by inter­molecular O—H⋯O hydrogen bonds. Mol­ecules are further connected into a three-dimensional array by weak C—H⋯O inter­actions

Active Learning on a Programmable Photonic Quantum Processor

Training a quantum machine learning model generally requires a large labeled dataset, which incurs high labeling and computational costs. To reduce such costs, a selective training strategy, called active learning (AL), chooses only a subset of the original dataset to learn while maintaining the trained model's performance. Here, we design and implement two AL-enpowered variational quantum classifiers, to investigate the potential applications and effectiveness of AL in quantum machine learning. Firstly, we build a programmable free-space photonic quantum processor, which enables the programmed implementation of various hybrid quantum-classical computing algorithms. Then, we code the designed variational quantum classifier with AL into the quantum processor, and execute comparative tests for the classifiers with and without the AL strategy. The results validate the great advantage of AL in quantum machine learning, as it saves at most $85\%$ labeling efforts and $91.6\%$ percent computational efforts compared to the training without AL on a data classification task. Our results inspire AL's further applications in large-scale quantum machine learning to drastically reduce training data and speed up training, underpinning the exploration of practical quantum advantages in quantum physics or real-world applications

Digital supply chain: literature review of seven related technologies

This paper systematically reviews literature related with digital supply chains (DSC) and investigates the application status and development trend of different digital technologies in supply chain management. The review is conducted from the perspective of seven key digital supply chain technologies, i.e. Internet of Things (IoT) & Radio Frequency Identification (RFID), 5th Generation Mobile Communication Technology (5G), 3D Printing, Big data (BD), Blockchain, Digital Twins (DT), and Intelligent autonomous vehicles (IAVs). It highlights the main limitations and opportunities of the various DSC technologies, provides an overview of prior studies, and identifies knowledge gaps by outlining the advantages, weaknesses and restrictions of individual technology. The paper also aims at providing a development framework as a roadmap for the match of different digital technologies with different strategic goals

Epidemic Pleurodynia Caused by Coxsackievirus B3 at a Medical Center in Northern Taiwan

Epidemic pleurodynia is seldom reported in Southeast Asia and there has been no report from Taiwan. We conducted a retrospective chart review of children = 18 years of age in the National Taiwan University Hospital from January 1 to December 31, 2005. Epidemic pleurodynia was defined as an acute illness characterized by sharp localized pain over the chest or upper abdomen. Patients with known heart diseases or pulmonary consolidations were excluded. In total, 28 patients met the case definition of epidemic pleurodynia. Coxsackievirus B3 (CB3) was isolated in 15 (60%) of the 25 throat swab specimens. Four (14%) of the 28 patients presented chest wall tenderness and only one (6%) of the 18 patients tested had an elevated creatinine kinase level. Twenty-one (75%) of the 28 patients described pleuritic chest pains and 10 (45%) of the 22 chest radiographies exhibited pulmonary infiltrates or pleural effusions. Six patients were observed with tonsillar exudates and one was confirmed to have a CB3 urinary tract infection. The clinical features and radiological findings suggest that CB3-associated epidemic pleurodynia might be a disease of the pleura and occasionally spreads to nearby tissues, resulting in chest wall myositis, pulmonary infiltrates and myopericarditis