1,2-Bis(4-nitro­benzo­yl)hydrazine

The title mol­ecule, C14H10N4O6, crystallizes with one half-mol­ecule in the asymmetric unit; the mid-point of the N—N bond lies on an inversion centre. The nitro and amide groups are twisted with respect to the benzene ring, making dihedral angles of 14.6 (5) and 31.1 (5)°, respectively. In the crystal structure, mol­ecules are linked through N—H⋯O hydrogen bonding between the imino and carbonyl groups

2-Chloro-5-(chloro­meth­yl)pyridine

The title compound, C6H5Cl2N, is almost planar, with an r.m.s. deviation of 0.0146 Å for all atoms except for the 5-choloromethyl Cl atom. The offset Cl atom lies above this plane with a Cl—C—C angle of 111.11 (17)°. In the crystal, mol­ecules are connected via inter­molecular C—H⋯N hydrogen bonds, forming dimers

Monitoring thermal pollution in rivers downstream of dams with Landsat ETM+ thermal infrared images

Dams play a significant role in altering the spatial pattern of temperature in rivers and contribute to thermal pollution, which greatly affects the river aquatic ecosystems. Understanding the temporal and spatial variation of thermal pollution caused by dams is important to prevent or mitigate its harmful effect. Assessments based on in-situ measurements are often limited in practice because of the inaccessibility of water temperature records and the scarcity of gauges along rivers. By contrast, thermal infrared remote sensing provides an alternative approach to monitor thermal pollution downstream of dams in large rivers, because it can cover a large area and observe the same zone repeatedly. In this study, Landsat Enhanced Thematic Mapper Plus (ETM+) thermal infrared imagery were applied to assess the thermal pollution caused by two dams, the Geheyan Dam and the Gaobazhou Dam, located on the Qingjiang River, a tributary of the Yangtze River downstream of the Three Gorges Reservoir in Central China. The spatial and temporal characteristics of thermal pollution were analyzed with water temperatures estimated from 54 cloud-free Landsat ETM+ scenes acquired in the period from 2000 to 2014. The results show that water temperatures downstream of both dams are much cooler than those upstream of both dams in summer, and the water temperature remains stable along the river in winter, showing evident characteristic of the thermal pollution caused by dams. The area affected by the Geheyan Dam reaches beyond 20 km along the downstream river, and that affected by the Gaobazhou Dam extends beyond the point where the Qingjiang River enters the Yangtze River. Considering the long time series and global coverage of Landsat ETM+ imagery, the proposed technique in the current study provides a promising method for globally monitoring the thermal pollution caused by dams in large rivers

Proposal for a near-field optomechanical system with enhanced linear and quadratic coupling

We propose a realistic system with separated optical and mechanical degrees of freedom, in which a high-mechanical-quality silicon nitride membrane is placed upon a high-optical-quality whispering gallery microcavity. The strongly enhanced linear optomechanical coupling, together with simultaneously low optical and mechanical losses in the present system, results in a remarkable single-photon cooperativity exceeding 300. This unprecedented cooperativity in the optomechanical system enables optical nonlinearity at low light intensities and holds great potential in generating, storing, and implementing quantum states. Moreover, the device gives rise to significantly stronger quadratic optomechanical coupling than achieved to date, which is desirable for measuring phonon shot noise with a high signal-to-noise ratio.Comment: 14 pages, 5 figure

Understanding the Mechanism of Deep Learning Frameworks in Lesion Detection for Pathological Images with Breast Cancer

With the advances of scanning sensors and deep learning algorithms, computational pathology has drawn much attention in recent years and started to play an important role in the clinical workflow. Computer-aided detection (CADe) systems have been developed to assist pathologists in slide assessment, increasing diagnosis efficiency and reducing misdetections. In this study, we conducted four experiments to demonstrate that the features learned by deep learning models are interpretable from a pathological perspective. In addition, classifiers such as the support vector machine (SVM) and random forests (RF) were used in experiments to replace the fully connected layers and decompose the end-to-end framework, verifying the validity of feature extraction in the convolutional layers. The experimental results reveal that the features learned from the convolutional layers work as morphological descriptors for specific cells or tissues, in agreement with the diagnostic rules in practice. Most of the properties learned by the deep learning models summarized detection rules that agree with those of experienced pathologists. The interpretability of deep features from a clinical viewpoint not only enhances the reliability of AI systems, enabling them to gain acceptance from medical experts, but also facilitates the development of deep learning frameworks for different tasks in pathological analytics

In Vitro Activity of Plant Extracts and Alkaloids against Clinical Isolates of Extended-Spectrum b-Lactamase (ESBL)-Producing Strains

The antibacterial activity of 80% ethanol extracts of 10 medicinal plants collected in Yunnan (Southwest China), was tested against clinical isolates of extended-spectrum b-lactamase (ESBL)-producing strains. Their MIC values ranged between 1.56–12.50 mg/mL. The most active plant extract was Chelidonium majus L. (MIC = 1.56 mg/mL). Two potent isoquinoline alkaloids, 8-hydroxydihydrosanguinarine and 8-hydroxydihydrochelerythrine, were identified as the major active principles through bioassay-guided fractionation and identification of the active ethyl acetate fraction from C. majus, with minimum MIC/MBC values of 15.63/62.50 mg/mL

Role of the Diphosphine Chelate in Emissive, Charge-Neutral Iridium(III) Complexes

A class of neutral tris-bidentate Ir(III) metal complexes incorporating a diphosphine as a chelate is prepared and characterized here for the first time. Treatment of [Ir(dppb)(tht)Cl3] (1) with fppzH afforded the dichloride complexes, trans-(Cl,Cl)[Ir(dppb)(fppz)Cl2] (2) and cis-(Cl,Cl)[Ir(dppb)(fppz)Cl2] (3). The reaction of 3 with the dianionic chelate precursor bipzH2 or mepzH2, in DMF gave the complex [Ir(dppb)(fppz)(bipz)] (4) or [Ir(dppb)(fppz)(mepz)] (5), respectively. In contrast, a hydride complex [Ir(dppb)(fppz)(bipzH)H] (6) was isolated instead of 4 in protic solvent, namely: DGME. All complexes 2 - 6 are luminescent in powder forms and thin films where the dichlorides (2, 3) emit with maxima at 590-627 nm (orange) and quantum yields (Q.Y.s) up to 90% whereas the tris-bidentate (4, 5) and hydride (6) complexes emit at 455-458 nm (blue) with Q.Y.s up to 70%. Hybrid TD-DFT calculations showed considerable MLCT contribution to the orange-emitting 2 and 3 but substantial ligand-centered 3ππ* transition character in the blue-emitting 4 - 6. The dppb does not participate to these radiative transitions in 4 - 6, but it provides the rigidity and steric bulk needed to promote the luminescence by suppressing the self-quenching in the solid state. Fabrication of an OLED with dopant 5 gave a deep blue CIE chromaticity of (0.16, 0.15). Superior blue emitters, which are vital in OLED applications, may be found in other neutral Ir(III) complexes containing phosphine chelates

Requirement of Siderophore Biosynthesis for Plant Colonization by Salmonella enterica

Contaminated fresh produce has become the number one vector of nontyphoidal salmonellosis to humans. However, Salmonella enterica genes essential for the life cycle of the organism outside the mammalian host are for the most part unknown. Screening deletion mutants led to the discovery that an aroA mutant had a significant root colonization defect due to a failure to replicate. AroA is part of the chorismic acid biosynthesis pathway, a central metabolic node involved in aromatic amino acid and siderophore production. Addition of tryptophan or phenylalanine to alfalfa root exudates did not restore aroA mutant replication. However, addition of ferrous sulfate restored replication of the aroA mutant, as well as alfalfa colonization. Tryptophan and phenylalanine auxotrophs had minor plant colonization defects, suggesting that suboptimal concentrations of these amino acids in root exudates were not major limiting factors for Salmonella replication. An entB mutant defective in siderophore biosynthesis had colonization and growth defects similar to those of the aroA mutant, and the defective phenotype was complemented by the addition of ferrous sulfate. Biosynthetic genes of each Salmonella siderophore, enterobactin and salmochelin, were upregulated in alfalfa root exudates, yet only enterobactin was sufficient for plant survival and persistence. Similar results in lettuce leaves indicate that siderophore biosynthesis is a widespread or perhaps universal plant colonization fitness factor for Salmonella, unlike phytobacterial pathogens, such as Pseudomonas and Xanthomonas

Therapeutic effect of Rho kinase inhibitor FSD-C10 in a mouse model of Alzheimer\u27s disease.

Fasudil, a Rho kinase (ROCK) inhibitor, effectively inhibits disease severity in a mouse model of Alzheimer\u27s disease (AD). However, given its significant limitations, including a relatively narrow safety window and poor oral bioavailability, Fasudil is not suitable for long-term use. Thus, screening for ROCK inhibitor(s) that are more efficient, safer, can be used orally and suitable for long-term use in the treatment of neurodegenerative disorders is required. The main purpose of the present study is to explore whether FSD-C10, a novel ROCK inhibitor, has therapeutic potential in amyloid precursor protein/presenilin-1 transgenic (APP/PS1 Tg) mice, and to determine possible mechanisms of its action. The results showed that FSD-C10 effectively improved learning and memory impairment, accompanied by reduced expression of amyloid-β1-42 (Aβ 1-42 ), Tau protein phosphorylation (P-tau) and β-site APP-cleaving enzyme in the hippocampus and cortex area of brain. In addition, FSD-C10 administration boosted the expression of synapse-associated proteins, such as postynaptic density protein 95, synaptophsin, α-amino 3-hydroxy-5-methyl-4-isoxa-zolep-propionate receptor and neurotrophic factors, e,g., brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor. Taken together, our results demonstrate that FSD-C10 has therapeutic potential in the AD mouse model, possibly through inhibiting the formation of Aβ 1-42 and P-tau, and promoting the generation of synapse-associated proteins and neurotrophic factors