Catalytic prenyl conjugate additions for synthesis of enantiomerically enriched PPAPs.

Polycyclic polyprenylated acylphloroglucinols (PPAPs) are a class of >400 natural products with a broad spectrum of bioactivity, ranging from antidepressant and antimicrobial to anti-obesity and anticancer activity. Here, we present a scalable, regio-, site-, and enantioselective catalytic method for synthesis of cyclic β-prenyl ketones, compounds that can be used for efficient syntheses of many PPAPs in high enantiomeric purity. The transformation is prenyl conjugate addition to cyclic β-ketoesters promoted by a readily accessible chiral copper catalyst and involving an easy-to-prepare and isolable organoborate reagent.

Bioconversion of agriculture by-products with functionally enhanced Streptomyces sp. SCUT-3: Fish skin as a model.

With the global population continuously rising, efficient bioconversion of inedible agricultural by-products is crucial for human food and energy sustainability. We here propose solid-state fermentation approaches to efficiently convert biopolymers into oligomers/monomers by accelerating the natural degradation process of the versatile Streptomyces sp. strain SCUT-3.

Too much social media? Unveiling the effects of determinants in social media fatigue.

Introduction: With the boom in social media, many people spend a lot of time on these platforms. Among them, some developed negative emotions, such as fatigue, depression, or disinterest in communicating, and used social media temporarily or permanently. Therefore, this study aims to explore the antecedents of social media fatigue, including social media helpfulness, social media self-efficacy, online subjective well-being, social comparison, compulsive social media use, privacy concerns, fear of missing out, and information overload, and to further discuss the determinants of social media fatigue on social anxiety and lurking.

Synthesis of --Cl,CF-Substituted Alkenes by Stereoselective Cross-Metathesis and the Role of Disubstituted Mo Alkylidenes.

Stereochemically defined organofluorine compounds are central to drug discovery and development. Here, we present a catalytic cross-metathesis method for the synthesis of -trisubstituted olefins that contain a Cl- and a CF-bound carbon terminus. Notably, the process is stereo, which is in contrast to the existing stereoretentive strategies that also involve a trisubstituted olefin as starting material.

Non-hypothetical projection pursuit regression for the prediction of hydration heat of Portland-cement-based cementitious system.

In this study, the non-hypothetical projection pursuit regression (NH-PPR) is proposed. The proposed NH-PPR model can predict the hydration heat based on the four cement phases, FA, SL, cement fineness and hydration time. The NH-PPR model is proposed by using the multiple layer iteration method and the non-hypothetical and non-parametric ridge functions to enhance accuracy and solve the problems caused by the parameter selection and the subjective hypothesis.

Taking Olefin Metathesis to the Limit: Stereocontrolled Synthesis of Trisubstituted Alkenes.

ConspectusIn this Account, we share the story of the development of catalytic olefin metathesis processes that efficiently deliver a wide range of acyclic and macrocyclic - or -trisubstituted alkenes. The tale starts with us unveiling, in collaboration with Richard Schrock and his team, the blueprint in 2009 for the design of kinetically controlled -selective olefin metathesis reactions. This paved the way for the development of Mo-, W-, and Ru-based catalysts and strategies for synthesizing countless linear and macrocyclic -olefins.

Balancing Biases and Preserving Privacy on Balanced Faces in the Wild.

There are demographic biases present in current facial recognition (FR) models. To measure these biases across different ethnic and gender subgroups, we introduce our Balanced Faces in the Wild (BFW) dataset. This dataset allows for the characterization of FR performance per subgroup.

Global Aligned Structured Sparsity Learning for Efficient Image Super-Resolution.

Efficient image super-resolution (SR) has witnessed rapid progress thanks to novel lightweight architectures or model compression techniques (e.g., neural architecture search and knowledge distillation).

Catalytic Cross-Metathesis Reactions That Afford - and -Trisubstituted Alkenyl Bromides: Scope, Applications, and Mechanistic Insights.

Stereochemically defined trisubstituted alkenes with a bromide and a methyl group at a terminus can be readily and stereoretentively derivatized through catalytic cross-coupling, affording unsaturated fragments found in many bioactive natural products. A direct method for generating such entities would be by stereocontrolled catalytic cross-metathesis (CM). Such methods are scarce however.

-Trisubstituted α,β-Unsaturated Esters and Acid Fluorides through Stereocontrolled Catalytic Cross-Metathesis.

Catalytic cross-metathesis (CM) reactions that can generate trisubstituted alkenes in high stereoisomeric purity are important but remain limited in scope. Here, CM reactions are introduced that generate -trisubstituted α-methyl, α,β-unsaturated, alkyl and aryl esters, thiol esters, and acid fluorides. Transformations are promoted by a Mo bis-aryloxide, a monoaryloxide pyrrolide, or a monoaryloxide chloride complex; air-stable and commercially available paraffin tablets containing a Mo complex may also be used.

Self-directed online machine learning for topology optimization.

Topology optimization by optimally distributing materials in a given domain requires non-gradient optimizers to solve highly complicated problems. However, with hundreds of design variables or more involved, solving such problems would require millions of Finite Element Method (FEM) calculations whose computational cost is huge and impractical. Here we report Self-directed Online Learning Optimization (SOLO) which integrates Deep Neural Network (DNN) with FEM calculations.

Semi-Supervised Dual Relation Learning for Multi-Label Classification.

In a real-world scenario, an object could contain multiple tags instead of a single categorical label. To this end, multi-label learning (MLL) emerged. In MLL, the feature distributions are long-tailed and the complex semantic label relation and the long-tailed training samples are the main challenges.

[Value of ginsenoside Rb1 in alleviating coronary artery lesion in a mouse model of Kawasaki disease].

Objective: To study the effect and related signaling pathways of ginsenoside Rb1 in the treatment of coronary artery lesion (CAL) in a mouse model of Kawasaki disease (KD).

Methods: BALB/c mice were randomly divided into a control group, a model group, an aspirin group, a low-dose ginsenoside Rb1 group (50 mg/kg), and a high-dose ginsenoside Rb1 group (100 mg/kg), with 12 mice in each group. All mice except those in the control group were given intermittent intraperitoneal injection of 10% bovine serum albumin to establish a mouse model of KD.

Impact of Ethylene on Efficiency and Stereocontrol in Olefin Metathesis: When to Add It, When to Remove It, and When to Avoid It.

Ethylene is the byproduct of olefin metathesis reactions that involve one or more terminal alkenes. Its volatility is one reason why many cross-metathesis or ring-closing metathesis processes, which are reversible transformations, are efficient. However, because ethylene can be converted to a methylidene complex, which is a highly reactive but relatively unstable species, its concentration can impact olefin metathesis in other ways.

Comparing sexual behaviours and knowledge between domestic students and Chinese international students in Australia: findings from two cross-sectional studies.

Few studies investigate sexual health among Chinese international students in Australia. We recruited domestic (n = 623) and Chinese international (n = 500) students for separate online surveys on sexual behaviours and knowledge. Samples were compared using Chi square, Fisher's exact and equality of medians tests.

Sesquiterpenes with Phytopathogenic Fungi Inhibitory Activities from Fungus from Sonn.

A new monosesquiterpene diacetylgliocladic acid (), a new dimeric sesquiterpene divirensol H (), and two exceptionally novel trimeric sesquiterpene trivirensols A and B ( and ), together with another eight known congeners, were purified from an endophytic fungus FY06, derived from Sonn. whose fruit is a delicious and popular food. All of them were identified by comprehensive spectroscopic analysis, combined with biosynthetic considerations.

Endobronchial ultrasound: Echoing in the field of pediatrics.

Endobronchial ultrasound (EBUS) is a useful technique for the diagnosis and staging of the lung and mediastinal lesions, which is crucial for selecting treatment protocol. Under EBUS guidance, transbronchial needle aspiration (TBNA) is widely applied for obtaining specimens for histological, cytological, and molecular evaluation. Recently, the EBUS scope designed for adults has been used in large pediatric candidates.

Permeable reactive barrier of coarse sand-supported zero valent iron for the removal of 2,4-dichlorophenol in groundwater.

In this study, coarse sand-supported zero valent iron (ZVI) composite was synthesized by adding sodium alginate to immobilize. Composite was detected by scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray fluorescence (XRF). SEM results showed that composite had core-shell structure and a wide porous distribution pattern.