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1.
Artículo en Inglés | MEDLINE | ID: mdl-38748523

RESUMEN

Weakly supervised object detection (WSOD) and semantic segmentation with image-level annotations have attracted extensive attention due to their high label efficiency. Multiple instance learning (MIL) offers a feasible solution for the two tasks by treating each image as a bag with a series of instances (object regions or pixels) and identifying foreground instances that contribute to bag classification. However, conventional MIL paradigms often suffer from issues, e.g., discriminative instance domination and missing instances. In this article, we observe that negative instances usually contain valuable deterministic information, which is the key to solving the two issues. Motivated by this, we propose a novel MIL paradigm based on negative deterministic information (NDI), termed NDI-MIL, which is based on two core designs with a progressive relation: NDI collection and negative contrastive learning (NCL). In NDI collection, we identify and distill NDI from negative instances online by a dynamic feature bank. The collected NDI is then utilized in a NCL mechanism to locate and punish those discriminative regions, by which the discriminative instance domination and missing instances issues are effectively addressed, leading to improved object-and pixel-level localization accuracy and completeness. In addition, we design an NDI-guided instance selection (NGIS) strategy to further enhance the systematic performance. Experimental results on several public benchmarks, including PASCAL VOC 2007, PASCAL VOC 2012, and MS COCO, show that our method achieves satisfactory performance. The code is available at: https://github.com/GC-WSL/NDI.

2.
J Chromatogr A ; 1722: 464904, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38626539

RESUMEN

A continuously regenerated cationic impurity removal device (CR-CRD) has been fabricated and applied for ion chromatography (IC). The removal of cationic impurities is realized by electrodialytically replacing the cationic impurities with hydronium ions. The device is configured in a sandwich structure and the central eluent channel is respectively isolated from both electrodes by stacked cation exchange membranes and a bipolar membrane (BPM) plus stacked anion exchange membranes. The eluent channel is packed with cation exchange resins in hydronium form and their continuous regeneration can be achieved by electrodialysis. A desirable feature of the device is gas-free, and no degasser is required. It showed sufficient ability to remove cationic impurities, as indicated by > 99.9 % removal of 10 mL of 1 mM LiOH solution injected (∼10 µmol) or continuous removal of 1 mM LiOH solution at the flow rate of 1 mL/min (1 µmol/min). A useful application was for sample pretreatment in nuclear power industry, by eliminating strong matrix interference of the sample containing LiOH (1 mM) and boric acid (2000 mg/L) with trace anion analysis.


Asunto(s)
Cationes , Cromatografía por Intercambio Iónico/métodos , Cromatografía por Intercambio Iónico/instrumentación , Cationes/química , Membranas Artificiales , Resinas de Intercambio de Catión/química , Diseño de Equipo
3.
Biotechnol J ; 19(4): e2300723, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38622797

RESUMEN

Polyurethane (PU) is a complex polymer synthesized from polyols and isocyanates. It contains urethane bonds that resist hydrolysis, which decreases the efficiency of biodegradation. In this study, we first expressed the amidase GatA250, and then, assessed the enzymatic characterization of GatA250 and its efficiency in degrading the polyester-PU. GatA250 degraded self-synthesized thermoplastic PU film and postconsumption foam with degradation efficiency of 8.17% and 4.29%, respectively. During the degradation, the film released 14.8 µm 4,4'-methylenedianiline (MDA), but 1,4-butanediol (BDO) and adipic acid (AA) were not released. Our findings indicated that GatA250 only cleaved urethane bonds in PU, and the degradation efficiency was extremely low. Hence, we introduced the cutinase LCC, which possesses hydrolytic activity on the ester bonds in PU, and then used both enzymes simultaneously to degrade the polyester-PU. The combined system (LCC-GatA250) had higher degradation efficiency for the degradation of PU film (42.2%) and foam (13.94%). The combined system also showed a 1.80 time increase in the production of the monomer MDA, and a 1.23 and 3.62 times increase in the production of AA and BDO, respectively, compared to their production recorded after treatment with only GatA250 or LCC. This study provides valuable insights into PU pollution control and also proposes applicable solutions to manage PU wastes through bio-recycling.


Asunto(s)
Compuestos de Anilina , Hidrolasas de Éster Carboxílico , Poliésteres , Poliuretanos , Poliésteres/química , Amidohidrolasas
4.
Appl Environ Microbiol ; 90(4): e0147723, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38445906

RESUMEN

Plastic degradation by biological systems emerges as a prospective avenue for addressing the pressing global concern of plastic waste accumulation. The intricate chemical compositions and diverse structural facets inherent to polyurethanes (PU) substantially increase the complexity associated with PU waste management. Despite the extensive research endeavors spanning over decades, most known enzymes exhibit a propensity for hydrolyzing waterborne PU dispersion (i.e., the commercial Impranil DLN-SD), with only a limited capacity for the degradation of bulky PU materials. Here, we report a novel cutinase (CpCut1) derived from Cladosporium sp. P7, which demonstrates remarkable efficiency in the degrading of various polyester-PU materials. After 12-h incubation at 55°C, CpCut1 was capable of degrading 40.5% and 20.6% of thermoplastic PU film and post-consumer foam, respectively, while achieving complete depolymerization of Impranil DLN-SD. Further analysis of the degradation intermediates suggested that the activity of CpCut1 primarily targeted the ester bonds within the PU soft segments. The versatile performance of CpCut1 against a spectrum of polyester-PU materials positions it as a promising candidate for the bio-recycling of waste plastics.IMPORTANCEPolyurethane (PU) has a complex chemical composition that frequently incorporates a variety of additives, which poses significant obstacles to biodegradability and recyclability. Recent advances have unveiled microbial degradation and enzymatic depolymerization as promising waste PU disposal strategies. In this study, we identified a gene encoding a cutinase from the PU-degrading fungus Cladosporium sp. P7, which allowed the expression, purification, and characterization of the recombinant enzyme CpCut1. Furthermore, this study identified the products derived from the CpCut1 catalyzed PU degradation and proposed its underlying mechanism. These findings highlight the potential of this newly discovered fungal cutinase as a remarkably efficient tool in the degradation of PU materials.


Asunto(s)
Hidrolasas de Éster Carboxílico , Cladosporium , Poliuretanos , Poliuretanos/química , Poliuretanos/metabolismo , Cladosporium/genética , Cladosporium/metabolismo , Estudios Prospectivos , Biodegradación Ambiental , Poliésteres/metabolismo , Plásticos
5.
Sci Rep ; 14(1): 6046, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38472299

RESUMEN

In the process of developing tight oil and gas reservoirs, multistage fractured horizontal wells (NFHWs) can greatly increase the production rate, and the optimal design of its fracturing parameters is also an important means to further increase the production rate. Accurate production prediction is essential for the formulation of effective development strategies and development plans before and during project execution. In this study, a novel workflow incorporating machine learning (ML) and particle swarm optimization algorithms (PSO) is proposed to predict the production rate of multi-stage fractured horizontal wells in tight reservoirs and optimize the fracturing parameters. The researchers conducted 10,000 numerical simulation experiments to build a complete training and validation dataset, based on which five machine learning production prediction models were developed. As input variables for yield prediction, eight key factors affecting yield were selected. The results of the study show that among the five models, the random forest (RF) model best establishes the mapping relationship between feature variables and yield. After verifying the validity of the Random Forest-based yield prediction model, the researchers combined it with the particle swarm optimization algorithm to determine the optimal combination of fracturing parameters under the condition of maximizing the net present value. A hybrid model, called ML-PSO, is proposed to overcome the limitations of current production forecasting studies, which are difficult to maximize economic returns and optimize the fracturing scheme based on operator preferences (e.g., target NPV). The designed workflow can not only accurately and efficiently predict the production of multi-stage fractured horizontal wells in real-time, but also be used as a parameter selection tool to optimize the fracture design. This study promotes data-driven decision-making for oil and gas development, and its tight reservoir production forecasts provide the basis for accurate forecasting models for the oil and gas industry.

6.
Water Res ; 255: 121477, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38520778

RESUMEN

Iodinated X-ray contrast media (ICM) are ubiquitously present in water sources and challenging to eliminate using conventional processes, posing a significant risk to aquatic ecosystems. Ultraviolet light-emitting diodes (UV-LED) emerge as a promising technology for transforming micropollutants in water, boasting advantages such as diverse wavelengths, elimination of chemical additives, and no induction of microorganisms' resistance to disinfectants. The research reveals that iohexol (IOX) degradation escalates as UV wavelength decreases, attributed to enhanced photon utilization efficiency. Pseudo-first-order rate constants (kobs) were determined as 3.70, 2.60, 1.31 and 0.65 cm2 J-1 at UV-LED wavelengths of 255, 265, 275 and 285 nm, respectively. The optical properties of dissolved organic matter (DOM) and anions undeniably influence the UV-LED photolysis process through photon competition and the generation of reactive substances. The influence of Cl- on IOX degradation was insignificant at UV-LED 255, but it promoted IOX degradation at 265, 275 and 285 nm. IOX degradation was accelerated by ClO2-, NO3-and HA due to the formation of various reactive species. In the presence of NO3-, the kobs of IOX followed the order: 265 > 255 > 275 > 285 nm. Photosensitizers altered the spectral dependence of IOX, and the intermediate photoactivity products were detected using electron spin resonance. The transformation pathways of IOX were determined through density functional theory calculations and experiments. Disinfection by-products (DBPs) yields of IOX during UV-LED irradiation decreased as the wavelength increased: 255 > 265 > 275 > 285 nm. The cytotoxicity index value decreased as the UV-LED wavelength increased from 255 to 285 nm. These findings are crucial for selecting the most efficient wavelength for UV-LED degradation of ICM and will benefit future water purification design.

7.
Heliyon ; 10(5): e26441, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38455566

RESUMEN

Reinjecting produced methane offers cost-efficiency and environmental benefits for enhances oil recovery. High minimum miscibility pressure (MMP) in methane-oil systems poses a challenge. To overcome this, researchers are increasingly focusing on using surfactants to reduce MMP, thus enhancing the effectiveness of methane injections for oil recovery. This study investigated the impact of pressure and temperature on the equilibrium interfacial tension of the CH4+n-decane system using molecular dynamics simulations and the vanishing interfacial tension technique. The primary goal was to assess the potential of surfactants in lowering MMP. Among four tested surfactants, ME-6 exhibited the most promise by reducing MMP by 14.10% at 373 K. Key findings include that the addition of ME-6 enriching CH4 at the interface, enhancing its solubility in n-decane, improving n-decane diffusion capacity, CH4 weakens n-decane interactions and strengthens its own interaction with n-decane. As the difference in interactions of n-decane with ME-6's ends decreases, the system trends towards a mixed phase. This research sets the stage for broader applications of mixed-phase methane injection in reservoirs, with the potential for reduced gas flaring and environmental benefits.

8.
Chem Commun (Camb) ; 60(17): 2373-2376, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38318933

RESUMEN

This work reports the construction of a miniaturized Ag/AgCl nanoelectrode on a nanopipette, which is capable of dual-functions of single-cell drug infusion and chloride detection and is envisioned to promote the study of chloride-correlated therapeutic effects.


Asunto(s)
Cloruros , Compuestos de Plata , Plata
9.
Rev Sci Instrum ; 95(2)2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38421259

RESUMEN

The sharpening switch is one of the most important elements in the trigger generator, which is used to sharpen the front of the trigger pulse. The breakdown performance of the sharpening switch has an important influence on the output and stability of the trigger generator. In this paper, a novel 200 kV capacitance-coupling pre-ionized sharpening switch, which can realize pre-ionization by dividing voltage through its own structural capacitances, is proposed and investigated. In order to obtain the optimal parameters of the pre-ionized sharpening switch, the influences of the electrode structure, electrode material, main gap distance, and pre-ionized gap distance on the breakdown performance are studied experimentally. The experimental results show that the electrode structure with a circular knife-edged cathode and a plate-shaped anode has the smallest breakdown jitter, followed by the needle-plate structure and the tapered ball-head structure. The stainless steel electrode has the smallest jitter, followed by graphite, aluminum, and brass electrodes. When the gap distances of the main gap and the pre-ionized gap are 13 and 1.5 mm, respectively, the breakdown stability of the pre-ionized sharpening switch is the best. Under an input voltage pulse with a rise time of about one microsecond, the jitter of the capacitance-coupling pre-ionized sharpening switch with the optimal parameters is 6.08 ns, which is about 0.6% of the rise time of the input pulse. The jitter decreases by 44.5% compared to the switch without pre-ionization. The rise time of the output pulse is sharpened to 17 ns, corresponding to a voltage rise rate of more than 11 kV/ns.

10.
Environ Technol ; : 1-12, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38164528

RESUMEN

The degradation kinetics, reaction pathways, and disinfection by-products formation of an organic UV filter, benzophenone-4 (BP4) during UV/persulfate oxidation were investigated. BP4 can hardly be degraded by UV alone, but can be effectively decomposed by UV/persulfate following pseudo-first order kinetics. BP4 degradation rate was enhanced with increasing persulfate dosage and decreasing pH from 8 to 5. However, the degradation rate of BP4 at pH 9 was higher than that at pH 8 because of the presence of phenolic group in BP4 structure. and SO4-⋅ were confirmed as the major contributors to BP4 decomposition in radical scavenging experiments, and the second-order rate constants between HO⋅ and BP4 as well as those between SO4-⋅ and BP4 were estimated by establishing and solving a kinetic model. The presence of Br- and humic acid inhibited the decomposition of BP4, while NO3- promoted it. The mineralisation of BP4 was only 9.1% at the persulfate concentration of 50 µM. Six degradation intermediates were identified for the promulgation of the reaction pathways of BP4 during UV/persulfate oxidation were proposed as a result. In addition, the formation of DBP in the sequential chlorination was evaluated at different persulfate dosages, pH values, and water matrix. The results of this study can provide essential knowledge for the effective control of DBP formation with reducing potential hazard to provide safe drinking water to the public.


BP4 can be effectively degraded by UV/persulfate process, following pseudo-first order kinetics.OH⋅ and SO4⋅ were identified as the main contributors to BP4 degradation during UV/persulfate process.The degradation pathways of BP4 during UV/persulfate process were proposed.Initial persulfate concentration and solution pH both affected the yield of DBPs.The higher toxic DBPs can be generated in the presence of Br or NO3.

11.
Anal Chem ; 96(5): 2094-2099, 2024 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-38258322

RESUMEN

Direct single-cell caspase-3 (Casp-3) analysis has remained challenging. A study of single-cell Casp-3 could contribute to revealing the fundamental pathogenic mechanisms in Casp-3-associated diseases. Here, a biomimetic nanochannel capable of single-cell sampling and ionic detection of intracellular Casp-3 is devised, which is established upon the installment of target-specific organic molecules (luc-DEVD) within the orifice of a glass nanopipette. The specific cleavage of luc-DEVD by Casp-3 could induce changes of inner-surface chemical groups and charge properties, thus altering the ionic response of the biomimetic nanochannel for direct Casp-3 detection. The practical applicability of this biomimetic nanochannel is confirmed by probing intracellular Casp-3 fluctuation upon drug stimulation and quantifying the Casp-3 evolution during induced apoptosis. This work realizes ionic single-cell Casp-3 analysis and provides a different perspective for single-cell protein analysis.


Asunto(s)
Apoptosis , Biomimética , Caspasa 3/metabolismo , Apoptosis/fisiología
12.
ACS Nano ; 18(6): 5029-5039, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38286031

RESUMEN

Clarifying the structure-reactivity relationship of non-noble-metal electrocatalysts is one of the decisive factors for the practical application of water electrolysis. In this field, the anodic oxygen evolution reaction (OER) with a sluggish kinetic process has become a huge challenge for large-scale production of high-purity hydrogen. Here we synthesize a layered quasi-nevskite metastable-phase cobalt oxide (LQNMP-Co2O3) nanosheet via a simple molten alkali synthesis strategy. The unit-cell parameters of LQNMP-Co2O3 are determined to be a = b = 2.81 Šand c = 6.89 Šwith a space group of P3̅m1 (No. 164). The electrochemical results show that the LQNMP-Co2O3 electrocatalyst enables delivering an ultralow overpotential of 266 mV at a current density of 10 mA cmgeo-2 with excellent durability. The operando XANES and EXAFS analyses clearly reveal the origin of the OER activity and the electrochemical stability of the LQNMP-Co2O3 electrocatalyst. Density functional theory (DFT) simulations show that the energy barrier of the rate-determining step (RDS) (from *O to *OOH) is significantly reduced on the LQNMP-Co2O3 electrocatalyst by comparing with simulated monolayered CoO2 (M-CoO2).

13.
ACS Nano ; 18(6): 5206-5217, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38294412

RESUMEN

The structure and electronic state of the active center in a single-atom catalyst undergo noticeable changes during a dynamic catalytic process. The metal atom active center is not well demonstrated in a dynamic manner. This study demonstrated that Li metal atoms, serving as active centers, can migrate on a C3N4 monolayer or between C3N4 monolayers when exposed to light irradiation. This migration alters the local coordination environment of Li in the C3N4 nanosheets, leading to a significant enhancement in photocatalytic activity. The photocatalytic H2O2 process could be maintained for 35 h with a 920 mmol/g record-high yield, corresponding to a 0.4% H2O2 concentration, which is far greater than the value (0.1%) of practical application for wastewater treatment. Density functional theory calculations indicated that dynamic Li-coordinated structures contributed to the superhigh photocatalytic activity.

14.
ACS Nano ; 18(5): 4551-4558, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38264998

RESUMEN

Developing nanoscale ratiometric techniques capable of biochemical response should prove of significance for precise applications with stringent spatial and biological restrictions. Here we present and devise the concept of θ-nanopore ratiometry, which uses ratiometric signals that could well address the serious concerns about device deviation in fabrication and nonspecific adsorption in the detection. As exemplified by a 200 nm θ-nanopore toward miRNA detection, the ±20 nm aperture drift could be mitigated and the issue of nonspecific adsorption could be minimized in the complex cytosolic environment. Practical application of this θ-nanopore ratiometry realizes the measurements of cytosolic miRNA-10b. This work has not only established a nanoscopic ratiometric technique but also enriched the extant armory of nanotools for single-cell studies and beyond.


Asunto(s)
Técnicas Biosensibles , MicroARNs , Nanoporos
15.
Environ Technol ; 45(11): 2132-2143, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36601874

RESUMEN

The efficient removal of 2-Methylisoborneol (2-MIB), a typical odour component, in water treatment plants (WTPs), poses a great challenge to conventional water treatment technology due to its chemical stability. In this study, the combination of ultraviolet light-emitting diode (UV-LED) and chlorine (UV-LED/chlorine) was exploited for 2-MIB removal, and the role of ultraviolet (UV) wavelength was investigated systematically. The results showed that UV or chlorination alone did not degrade 2-MIB effectively, and the UV/chlorine process could degrade 2-MIB efficiently, following the pseudo-first-order kinetic model. The 275 nm UV exhibited higher 2-MIB degradation efficiency in this UV-LED/chlorine system than 254 nm UV, 265 nm UV and 285 nm UV due to the highest mole adsorption coefficient and quantum yield of chlorine in 275 nm UV. ·OH and ·Cl produced in the 275 nm UV/chlorine system played major roles in 2-MIB degradation. HCO3- and Natural organic matter (NOM), prevalent in water, consumed ·OH and ·Cl, thus inhibiting the 2-MIB degradation by UV-LED/chlorine. In addition, NOM and 2-MIB could form a photonic competition effect. The degradation of 2-MIB by UV-LED/chlorine was done mainly through dehydration and demethylation, and odorous intermediates, such as camphor, were produced. 2-MIB was degraded through the α bond fracture and six-membered ring opening to form saturated or unsaturated hydrocarbons and aldehydes. Four DBPs, chloroform (CF), trichloroacetaldehyde (TCE), trichloroacetone (TCP) and dichloroacetone (DCP), were mainly generated, and CF was the most significant by-product.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Cloro/química , Desinfección/métodos , Contaminantes Químicos del Agua/química , Rayos Ultravioleta , Halogenación , Cloroformo , Cinética , Purificación del Agua/métodos , Oxidación-Reducción
16.
Sci Total Environ ; 912: 168920, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38029977

RESUMEN

Pre-oxidation and powdered activate carbon (PAC) are usually used to remove algae and odorants in drinking waterworks. However, the influence of interaction between oxidants and PAC on the treatment performance are scarcely known. This study systematically investigated the combination schemes of four oxidants (KMnO4, NaClO, ClO2, and O3) and PAC on the inactivation of Microcystis aeruginosa cells and removal of four frequently detected odorants in raw water (diethyl disulfide (DEDS), 2,2'-oxybis(1chloropropane) (DCIP), 2-methylisoborneol (2-MIB) and geosmin (GSM)). O3 showed highest pseudo-first-order removal rate for all four compounds and NaClO exhibited highest inactivation rates for the cell viability and Chlorophyll a (Chl-a). The Freundlich model fitted well for the adsorption of DEDS and DCIP by PAC. When treated by combined oxidation/PAC, the removal ratio of algae cells and odorants were lower (at least 1.6 times) than the sum of removal ratios obtained in oxidation or PAC adsorption alone. Among these four oxidants, the highest synchronous control efficiency of odorants (52 %) and algae (66 %) was achieved by NaClO/PAC. Prolonging the dosage time interval promoted the removal rates. The pre-PAC/post-oxidation processes possessed comparable efficiency for the removal of odorants and algae cells comparing with pre-oxidation/post-PAC process, but significantly inhibited formation of disinfection byproducts (DBPs), especially for the formation of C-DBPs (for NaClO and ClO2), bromate (for O3) and chlorate/chlorite (for ClO2). This study could provide a better understanding of improving in-situ operation of the combined pre-treatments of oxidation and PAC for source water.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Oxidantes , Desinfección , Carbón Orgánico , Odorantes , Adsorción , Polvos , Clorofila A , Agua
17.
Nano Lett ; 24(1): 202-208, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38126308

RESUMEN

This work presents a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas-nanopipette nano-electrochemistry (Cas = CRISPR-associated proteins) capable of ultrasensitive microRNA detection. Nanoconfinement of the CRISPR/Cas13a within a nanopipette leads to a high catalytic efficacy of ca. 169 times higher than that in bulk electrolyte, contributing to the amplified electrochemical responses. CRISPR/Cas13a-enabled detection of representative microRNA-25 achieves a low limit of detection down to 10 aM. Practical application of this method is further demonstrated for single-cell and real human serum detection. Its general applicability is validated by addressing microRNA-141 and the SARS-CoV-2 RNA gene fragment. This work introduces a new CRISPR/Cas-empowered nanotechnology for ultrasensitive nano-electrochemistry and bioanalysis.


Asunto(s)
MicroARNs , Nanoporos , Humanos , MicroARNs/genética , MicroARNs/análisis , Sistemas CRISPR-Cas/genética , ARN Viral
18.
Mol Biol Rep ; 50(12): 10651-10656, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37962705

RESUMEN

BACKGROUND: Rhinogobio nasutus, an endemic species from the Yellow River, is listed under the second class of the National Key Protected Wildlife List in China due to its dramatically decreased population. Despite its important status, the mitochondrial genes and phylogenetic relationships of R. nasutus are unknown. METHODS AND RESULTS: The complete mitochondrial genome of R. nasutus was sequenced, assembled, and annotated for the first time. The mitochondrial genome was 16,609 bp in length, consisting of 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and 1 non-coding control region. The gene order in the mitochondrial genome of R. nasutus was identical to that of other Rhinogobios species. Analysis of synonymous and non-synonymous nucleotide substitutions showed that the Ka/Ks ratio in all tested protein-coding genes was less than 1, indicating that these genes were evolving under purifying selection. Further phylogenetic analysis showed that R. nasutus was first clustered with R. typus, then grouped with the other two Rhinogobio species, indicating the phylogenetically close relationship between R. nasutus and R. typus. CONCLUSIONS: This was the first genomic resource developed for R. nasutus, which could not only improve our understanding of its phylogenetic status, but also serve as a genomic tool for the development of genetic markers that will be used in conservation and evolutionary genetics studies.


Asunto(s)
Cipriniformes , Genoma Mitocondrial , Animales , Filogenia , Genoma Mitocondrial/genética , Ríos , Análisis de Secuencia de ADN/métodos , Cipriniformes/genética
19.
Org Lett ; 25(46): 8326-8331, 2023 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-37943666

RESUMEN

Triazoles are privileged structural motifs that are embedded in a number of molecules with interesting biological activities. In this work, we developed a practical and general synthetic strategy to construct a medicinally important 5-amino-1,2,3-triazole moiety on DNA by coupling DNA-conjugated azides and monosubstituted acetonitriles via azide-acetonitrile "click" reaction. Under mild reaction conditions, this reaction displayed a broad substrate scope. Most substrates gave moderate-to-excellent conversions. Thus, this DNA-compatible reaction could be employed in practical DNA-encoded library (DEL) construction and potentially expand the chemical space of DNA-encoded libraries.


Asunto(s)
Azidas , Triazoles , Azidas/química , Triazoles/química , Química Clic , Acetonitrilos , ADN/química , Alquinos/química , Reacción de Cicloadición
20.
ACS Pharmacol Transl Sci ; 6(11): 1724-1733, 2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-37974618

RESUMEN

DNA-encoded libraries (DEL) have emerged as an important drug discovery technical platform for target-based compound library selection. The success rate of DEL depends on both the chemical diversity of combinatorial libraries and the accuracy of DNA barcoding. Therefore, it is critical that the chemistry applied to library construction should efficiently transform on a wide range of substrates while preserving the integrity of DNA tags. Although several analytical methods have been developed to measure DNA damage caused by DEL chemical reactions, efficient and cost-effective evaluation criteria for DNA damage detection are still demanding. Herein, we set standards for evaluating the DNA compatibility of chemistry development at the laboratory level. Based on four typical DNA damage models of three different DEL formats, we evaluated the detection capabilities of four analytical methods, including ultraperformance liquid chromatography (UPLC-MS), electrophoresis, quantitative polymerase chain reaction (qPCR), and Sanger sequencing. This work systematically revealed the scope and capability of different analytical methods in assessing DNA damages caused by chemical transformation. Based on the results, we recommended UPLC-MS and qPCR as efficient methods for DNA barcode integrity analysis in the early-stage development of DNA-compatible chemistry. Meanwhile, we identified that Sanger sequencing was unreliable to assess DNA damage in this application.

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