Publications by authors named "ZhiZhen Zhang"

Fluorinases represent the only known biological catalysts capable of forming carbon-fluorine bonds, but their slow catalytic rate limits their broader application. In this study, two fluorinases, FlA and FlA, were identified from a pool of 12 718 nonredundant proteins using a genome-mining approach, with FlA showing high catalytic activity. Both newly identified fluorinases contain a Phe50 residue in place of the Trp50 typically found in fluorinases.

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  • The aging global population has increased attention on health issues like dementia, particularly Alzheimer's disease (AD) and frontotemporal dementia (FTD), which affect quality of life for patients and caregivers.
  • The study used an open dataset of participants with AD, FTD, and healthy controls to identify key neural oscillations (theta, alpha, beta) that differentiate these groups through statistical methods and machine learning.
  • Findings revealed significant differences in neural activity patterns, with theta power negatively linked to cognitive function (MMSE scores), suggesting potential for early detection and screening of dementia-related diseases.
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Estimating the fraction absorbed (F) of orally ingested chemicals in the human gastrointestinal tract is pivotal for assessing chemical concentrations in the systemic circulation and informing potential toxicological impacts, especially in the era of "new approach methods" targeting chemical screening and prioritization. Here, we present an input-parsimonious and computationally efficient approach to support the screening-level estimation of F from partitioning (characterized using the octanol-water partition coefficient at pH 7.4, K) and transmembrane permeability (characterized using the Caco-2 apparent permeability, P), based on a mechanistic description of processes involved in chemical absorption: [Formula: see text] Our approach demonstrates satisfactory performance in predicting F for 176 hydrophobic and hydrophilic organic chemicals, with a Pearson correlation coefficient greater than 0.

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Alpha oscillations are associated with various psychiatric disorders, with many studies focusing on the prefrontal cortex, where transcranial alternating current stimulation (TACS) is applied in the alpha frequency band. This approach often involves selecting individualized alpha frequencies to resonate with their endogenous alpha oscillations. While strong alpha oscillations (8-13 Hz) are typically induced when the eyes are closed, they can also occur during the resting state with eyes open.

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Humans are widely exposed to semivolatile organic contaminants in indoor environments. Many contaminants have long lifetimes following partitioning to the large surface reservoirs present indoors, which leads to long exposure times to gas-phase oxidants and multiphase chemistry. Studies have shown selective multiphase oxidation of organics on indoor surfaces, but the presence of hydroxyl radicals with nonselective reactivity and evidence of multiphase OH radical reactivity toward common indoor contaminants indicates that there may be additional unknown transformation chemistry indoors.

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Four previously undescribed compounds talaromyester A () and purpuresters C-E (), together with known purpurester A () and purpuride G (), were isolated from the metabolites produced by the Mariana Trench sediment-derived fungus sp. SY2250. Compounds , two pairs of racemates, were separated on a chiral HPLC column.

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  • - The study investigates the protective effects of purified panaxadiol saponin (PDSF) and purified panaxatriol saponin (PTSF) against Parkinson’s disease (PD) in rat models, specifically focusing on motor dysfunction and damage to brain cells caused by rotenone exposure.
  • - Results show that PDSF provides significant protection to crucial brain cells, maintains the integrity of the blood-brain barrier, and helps regulate inflammatory factors, while PTSF fails to offer similar protection and may even worsen conditions when combined with PDSF.
  • - The findings suggest that PDSF has strong potential for both prevention and treatment of PD due to its ability to inhibit neuroinflammation and protect against cell
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  • Bipolar disorder (BD) is a serious mental illness that can be wrongly diagnosed or missed, causing problems for both people and society.
  • The study looked at brain activity measured by EEG (a way to see how the brain works) in people with BD compared to healthy individuals and found that BD patients had unusual brain wave patterns, especially in delta, theta, beta, and gamma frequencies.
  • The research emphasized that many factors, like age and medication, can affect the study results, so it's important to keep things consistent when studying BD.
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Metabolites produced by the genus Streptomyces are the most important resource for discovering bioactive compounds. In this study, chemical investigation on the metabolites produced by the marine-derived Streptomyces sp. ZZ735 in rice solid medium led to the isolation of eighteen compounds (1-18).

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Animal-free new approach methods promote chemical assessments based on the comparison between bioactivity and human internal concentrations, which necessitates a dependable knowledge of human oral bioavailability, i.e., the fraction of an orally ingested chemical that escapes from presystemic ("first-pass") metabolic processes and eventually enters systemic circulation.

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  • * This study isolated five strains of actinomycetes from the Mariana Trench, with strain B1075 showing the strongest antimicrobial properties and identified 25 flavonoid compounds linked to its biological activity.
  • * A gene crucial for genistein production was identified and found to be influenced by high pressure, indicating that these microorganisms' secondary metabolite synthesis is closely related to their harsh habitat, which may lead to new pharmaceutical developments.
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Fungi from the genus Aspergillus are important resources for the discovery of bioactive agents. This investigation characterized the isolation, structural elucidation, and antimicrobial evaluation of 46 metabolites produced by the marine-derived fungus Aspergillus sp. ZZ1861 in rice solid and potato dextrose broth liquid media.

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  • Echinocandin B and FR901379 are antifungal lipopeptides used to treat severe fungal infections, with modified fatty acid chains developed to reduce toxicity.
  • A new echinocandin E acylase (ECEA) was discovered from a Mariana Trench sediment sample, which helps to enhance the development of these antifungal compounds.
  • The findings highlight the potential of exploring deep-sea biodiversity for discovering new enzymes that can aid in developing therapeutics.
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Reliable estimation of chemical sorption from water to solid phases is an essential prerequisite for reasonable assessments of chemical hazards and risks. However, current fate and exposure models mostly rely on algorithms that lack the capability to quantify chemical sorption resulting from interactions with multiple soil constituents, including amorphous organic matter, carbonaceous organic matter, and mineral matter. Here, we introduce a novel, generic approach that explicitly combines the gravimetric composition of various solid constituents and poly-parameter linear free energy relationships to calculate the solid-water sorption coefficient () for non-ionizable or predominantly neutral organic chemicals with diverse properties in a neutral environment.

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The natural product α-cyclopiazonic acid (α-CPA) is a very potent Ca-ATPase inhibitor. The CPA family of compounds comprise over 80 chemical entities with at least five distinct skeletons. While α-CPA features a canonical 6/5/6/5/5 skeleton, the 6/5/6/5 skeleton is the most prevalent among the CPA family.

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A significant number of chemicals registered in national and regional chemical inventories require assessments of their potential "hazard" concerns posed to humans and ecological receptors. This warrants knowledge of their partitioning and reactivity properties, which are often predicted by quantitative structure-property relationships (QSPRs) and other semiempirical relationships. It is imperative to evaluate the applicability domain (AD) of these tools to ensure their suitability for assessment purpose.

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Fungi are important resource for the discovery of novel bioactive natural products. This study investigated the metabolites produced by Mariana-Trench-associated fungus sp. SY2601 in EY liquid and rice solid media, resulting in the isolation and structure determination of 28 metabolites, including five new compounds, asperindopiperazines A-C (-), 5-methoxy-8,9-dihydroxy-8,9-deoxyaspyrone (), and 12-aspertetranone D ().

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Methyl protodioscin (MPD) is the main component of total diosgenin, which was reported to reduce cholesterol and triglyceride levels potentially. This study aimed to investigate the beneficial effects of MPD against lipid disorder in hyperlipidemic gerbils induced by a high-fat diet (HFD). Hyperlipidemia was induced in gerbils by feeding them with HFD for six weeks, and a daily oral dose of MPD solution (25 and 50 mg/kg/day) was administered.

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Liquid crystal monomers (LCMs), a group of synthetic chemicals released from liquid crystal devices such as televisions and smartphones, have recently been recognized as emerging contaminants due to their widespread occurrence in the environment and potential negative impacts on human health. Airborne LCMs can undergo atmospheric oxidation reactions to form various transformation products. Despite the certainty of atmospheric transformation chemistry, the knowledge about the hazard properties of transformation products remains largely unknown.

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  • Non-target analysis (NTA) in chemistry often reveals numerous chemical features, prompting the need for a strategy to prioritize which compounds to investigate further.
  • The proposed strategy ranks these chemical features based on their potential for bioaccumulation in humans or wildlife, allowing researchers to focus on the most concerning compounds.
  • By analyzing environmental samples like house dust, this method determined that compounds such as polybrominated diphenyl ethers and other known indoor pollutants had lower dose-to-concentration ratios, making them top priorities for further structure elucidation.
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Persistent and mobile (PM) chemicals are considered emerging threats to the environment and drinking water because they can be transported over long distances, penetrate natural and artificial barriers, and resist removal by traditional water treatment procedures. Current chemical regulatory frameworks raise concerns over PM chemicals due to their potential to cause high human exposure through drinking water contamination. However, the criteria used to screen and identify these chemicals often rely on hazard properties related to stability and sorption, such as biodegradation half-lives and organic-carbon-normalized sorption coefficients as respective measures of P and M.

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Organic solar cells (OSCs) have attracted lots of attention owing to their low cost, lightweight, and flexibility properties. Nowadays, the performance of OSCs is continuously improving with the development of active layer materials. However, the traditional hole transport layer (HTL) material Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) presents insufficient conductivity and rapid degradation, which decreases the efficiency and stability of OSCs.

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Deep-sea fungi have evolved extreme environmental adaptation and possess huge biosynthetic potential of bioactive compounds. However, not much is known about the biosynthesis and regulation of secondary metabolites of deep-sea fungi under extreme environments. Here, we presented the isolation of 15 individual fungal strains from the sediments of the Mariana Trench, which were identified by internal transcribed spacer (ITS) sequence analysis as belonging to 8 different fungal species.

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Reliable chemical property data are the key to defensible and unbiased assessments of chemical emissions, fate, hazard, exposure, and risks. However, the retrieval, evaluation, and use of reliable chemical property data can often be a formidable challenge for chemical assessors and model users. This comprehensive review provides practical guidance for use of chemical property data in chemical assessments.

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