Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.045
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Nature ; 613(7943): 280-286, 2023 01.
Article in English | MEDLINE | ID: mdl-36631649

ABSTRACT

Macroscopic electric motors continue to have a large impact on almost every aspect of modern society. Consequently, the effort towards developing molecular motors1-3 that can be driven by electricity could not be more timely. Here we describe an electric molecular motor based on a [3]catenane4,5, in which two cyclobis(paraquat-p-phenylene)6 (CBPQT4+) rings are powered by electricity in solution to circumrotate unidirectionally around a 50-membered loop. The constitution of the loop ensures that both rings undergo highly (85%) unidirectional movement under the guidance of a flashing energy ratchet7,8, whereas the interactions between the two rings give rise to a two-dimensional potential energy surface (PES) similar to that shown by FOF1 ATP synthase9. The unidirectionality is powered by an oscillating10 voltage11,12 or external modulation of the redox potential13. Initially, we focused our attention on the homologous [2]catenane, only to find that the kinetic asymmetry was insufficient to support unidirectional movement of the sole ring. Accordingly, we incorporated a second CBPQT4+ ring to provide further symmetry breaking by interactions between the two mobile rings. This demonstration of electrically driven continual circumrotatory motion of two rings around a loop in a [3]catenane is free from the production of waste products and represents an important step towards surface-bound14 electric molecular motors.

2.
Nature ; 603(7900): 265-270, 2022 03.
Article in English | MEDLINE | ID: mdl-35264758

ABSTRACT

Molecular recognition1-4 and supramolecular assembly5-8 cover a broad spectrum9-11 of non-covalently orchestrated phenomena between molecules. Catalysis12 of such processes, however, unlike that for the formation of covalent bonds, is limited to approaches13-16 that rely on sophisticated catalyst design. Here we establish a simple and versatile strategy to facilitate molecular recognition by extending electron catalysis17, which is widely applied18-21 in synthetic covalent chemistry, into the realm of supramolecular non-covalent chemistry. As a proof of principle, we show that the formation of a trisradical complex22 between a macrocyclic host and a dumbbell-shaped guest-a molecular recognition process that is kinetically forbidden under ambient conditions-can be accelerated substantially on the addition of catalytic amounts of a chemical electron source. It is, therefore, electrochemically possible to control23 the molecular recognition temporally and produce a nearly arbitrary molar ratio between the substrates and complexes ranging between zero and the equilibrium value. Such kinetically stable supramolecular systems24 are difficult to obtain precisely by other means. The use of the electron as a catalyst in molecular recognition will inspire chemists and biologists to explore strategies that can be used to fine-tune non-covalent events, control assembly at different length scales25-27 and ultimately create new forms of complex matter28-30.

3.
Small ; : e2401123, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38659372

ABSTRACT

Matching the thickness of the graphitic carbon nitride (CN) nanolayer with the charge diffusion length is expected to compensate for the poor intrinsic conductivity and charge recombination in CN for photoelectrochemical cells (PEC). Herein, the compact CN nanolayer with tunable thickness is in situ coated on carbon fibers. The compact packing along with good contact with the substrate improves the electron transport and alleviates the charge recombination. The PEC investigation shows CN nanolayer of 93 nm-thick yields an optimum photocurrent of 116 µA cm-2 at 1.23 V versus RHE, comparable to most micrometer-thick CN layers, with a low onset potential of 0.2 V in 1 m KOH under 1 sun illumination. This optimum performance suggests the electron diffusion length matches with the thickness of the CN nanolayer. Further deposition of NiFe-layered double hydroxide enhanced the surface water oxidation kinetics, delivering an improved photocurrent of 210 µA cm-2 with IPCE of 12.8% at 400 nm. The CN nanolayer also shows extended potential in PEC organic synthesis. This work experimentally reveals the PEC behavior of the nanometer-thick CN layer, providing new insights into CN in the application of energy and environment-related fields.

4.
Langmuir ; 40(26): 13550-13561, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38902967

ABSTRACT

There has been a growing emphasis on facile preparation of binary heterogeneous composite materials. Leveraging the eco-friendly efficiency of supercritical CO2 technology, we achieved precise control over the influencing factors of mass transfer, enabling the accurate modulation of the resulting product morphology and properties. In the current study, CuxO/ZrOy composite materials were prepared using this technology and calcined to obtain electrode materials for the detection of cysteine (Cys). Essential comprehensive characterization techniques were employed to elucidate the heterojunction. The resulting electrode demonstrated a linear response to Cys within a concentration range of 0.5 nM to 1 µM, featuring a high sensitivity of 1035 µA·cm-2·µM-1 and a low detection limit of 97.3 nM. Thus, establishing a novel avenue for nonenzyme-based electrochemical sensors tailored for biologically active Cys detection through the implementation of a heterogeneous structure.

5.
Inorg Chem ; 63(9): 4185-4195, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38364251

ABSTRACT

Posttreatment of pristine metal-organic frameworks (MOFs) with suitable vapor may be an effective way to regulate their structures and properties but has been less explored. Herein, we report an interesting example in which a crystalline nonporous Eu(III)-MOF was transferred to a porous amorphous MOF (aMOF) via iodine vapor adsorption-desorption posttreatment, and the resulting aMOF showed improved turn-on sensing properties with respect to Ag+ ions. The crystalline Eu-MOF, namely, Eu-IPDA, was assembled from Eu(III) and 4,4'-{4-[4-(1H-imidazol-1-yl)phenyl]pyridine-2,6-diyl}dibenzoic acid (H2IPDA) and exhibited a two-dimensional (2D) coordination network based on one-dimensional secondary building blocks. The close packing of the 2D networks gives rise to a three-dimensional supramolecular framework without any significant pores. Interestingly, the nonporous Eu-IPDA could absorb iodine molecules when Eu-IPDA crystals were placed in iodine vapor at 85 °C, and the adsorption capacity was 1.90 g/g, which is comparable to those of many MOFs with large BET surfaces. The adsorption of iodine is attributed to the strong interactions among the iodine molecule, the carboxy group, and the N-containing group and leads to the amorphization of the framework. After immersion of the iodine-loaded Eu-IPDA in EtOH, approximately 89.7% of the iodine was removed, resulting in a porous amorphous MOF, denoted as a-Eu-IPDA. In addition, the remaining iodine in the a-Eu-IPDA framework causes strong luminescent quenching in the fluorescence emission region of the Eu(III) center when compared with that in Eu-IPDA. The luminescence intensity of a-Eu-IPDA in water suspensions was significantly enhanced when Ag+ ions were added, with a detection limit of 4.76 × 10-6 M, which is 1000 times that of pristine Eu-IPDA. It also showed strong anti-interference ability over many common competitive metal ions and has the potential to sense Ag+ in natural water bodies and traditional Chinese medicine preparations. A mechanistic study showed that the interactions between Ag+ and the absorbed iodine, the carboxylate group, and the N atoms all contribute to the sensing performance of a-Eu-IPDA.

6.
J Immunol ; 209(6): 1095-1107, 2022 09 15.
Article in English | MEDLINE | ID: mdl-35985789

ABSTRACT

Mammalian studies have demonstrated that B cell immune responses are regulated by mechanistic target of rapamycin complex 1 (mTORC1) signaling. Teleost fish represent the oldest living bony vertebrates that contain bona fide B cells. So far, whether the regulatory mechanism of mTORC1 signaling in B cells occurred in teleost fish is still unknown. In this study, we developed a fish model by using rapamycin (RAPA) treatment to inhibit mTORC1 signaling and demonstrated the role of mTORC1 signaling in teleost B cells. In support, we found inhibition of mTORC1 signaling by RAPA decreased the phagocytic capacity, proliferation, and Ig production of B cells. Critically, Flavobacterium columnare induced specific IgM binding in serum, and these titers were significantly inhibited by RAPA treatment, thus decreasing Ab-mediated agglutination of F. columnare and significantly increasing the susceptibility of fish upon F. columnare reinfection. Collectively, our findings elucidated that the mTORC1 pathway is evolutionarily conserved in regulating B cell responses, thus providing a new point for understanding the B cells functions in teleost fish.


Subject(s)
B-Lymphocytes , Signal Transduction , Animals , Fishes , Immunoglobulin M , Mammals , Mechanistic Target of Rapamycin Complex 1 , Sirolimus/pharmacology
7.
Pestic Biochem Physiol ; 200: 105814, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38582586

ABSTRACT

To explore active natural products against tobacco powdery mildew caused by Golovinomyces cichoracearum, an extract from the fermentation of endophytic Aspergillus fumigatus 0338 was investigated. The mechanisms of action for active compounds were also studied in detail. As a result, 14 indole alkaloid derivatives were isolated, with seven being newly discovered (1-7) and the remaining seven previously described (8-14). Notably, compounds 1-3 are rare linearly fused 6/6/5 tricyclic prenylated indole alkaloids, with asperversiamide J being the only known natural product of this kind. The isopentenyl substitutions at the 5-position in compounds 4 and 5 are also rare, with only compounds 1-(5-prenyl-1H-indol-3-yl)-propan-2-one (8) and 1-(6-methoxy-5-prenyl-1H-indol3-yl)-propan-2-one currently available. In addition, compounds 6 and 7 are new framework indole alkaloid derivatives bearing a 6-methyl-1,7-dihydro-2H-azepin-2-one ring. The purified compounds were evaluated for their activity against G. cichoracearum, and the results revealed that compounds 7 and 9 demonstrated obvious anti-G. cichoracearum activities with an inhibition rate of 82.6% and 85.2%, respectively, at a concentration of 250 µg/mL, these rates were better than that of the positive control agent, carbendazim (78.6%). The protective and curative effects of compounds 7 and 9 were also better than that of positive control, at the same concentration. Moreover, the mechanistic study showed that treatment with compound 9 significantly increased the structural tightness of tobacco leaves and directly affect the conidiospores of G. cichoracearum, thereby enhancing resistance. Compounds 7 and 9 could also induce systemic acquired resistance (SAR), directly regulating the expression of defense enzymes, defense genes, and plant semaphorins, which may further contribute to increased plant resistance. Based on the activity experiments and molecular dockings, the indole core structure may be the foundation of these compounds' anti-G. cichoracearum activity. Among them, the indole derivative parent structures of compounds 6, 7, and 9 exhibit strong effects. Moreover, the methoxy substitution in compound 7 can enhance their activity. By isolating and structurally identifying the above indole alkaloids, new candidates for anti-powdery mildew chemical screening were discovered, which could enhance the utilization of N. tabacum-derived fungi in pesticide development.


Subject(s)
Alkaloids , Aspergillus fumigatus , Neoprene , Nicotiana , Indole Alkaloids/pharmacology , Indole Alkaloids/chemistry , Alkaloids/pharmacology
8.
Int J Urol ; 31(3): 245-251, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37986214

ABSTRACT

OBJECTIVES: To evaluate the risk factors for postoperative complications in adolescents who undergo primary hypospadias repair and determine the time required for complication detection. METHODS: Our study included patients classified as Tanner stages three to five who underwent primary hypospadias repairs at our hospital from January 2015 to August 2022. The patients' baseline information, clinical characteristics, postoperative complications, and time to complication detection were collected. Cox regression analysis, ROC curves, Kaplan-Meier survival analyses, and the Mann-Whitney U test were used. RESULTS: The study comprised 143 patients, with a median age of 12.58 years. Postoperative complications were experienced by 66 patients. The length of the urethral defect was identified as an independent risk factor for postoperative complications. The ROC curve analysis identified 3 cm as the optimal cutoff value for the length of the urethral defect. The median time to complication detection was 30.5 days (IQR 23 to 209.25). 89.4% of the complications were identified within the first year. Patients with a urethral defect of <3 cm experienced a significantly longer time for the detection of urethral fistula compared to those with a urethral defect of ≥3 cm (p = 0.047). CONCLUSIONS: Our data indicate that adolescents with a urethral defect ≥3 cm have a higher risk of postoperative complications. Although most complications were identified within the first year, conducting long-term follow-ups for adolescents is recommended to identify potential subsequent complications that may arise from persistent urethral alterations.


Subject(s)
Hypospadias , Male , Humans , Adolescent , Infant , Child , Hypospadias/surgery , Retrospective Studies , Risk Factors , Urethra/surgery , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Postoperative Complications/surgery , Urologic Surgical Procedures, Male/adverse effects , Treatment Outcome
9.
Nano Lett ; 23(22): 10563-10570, 2023 Nov 22.
Article in English | MEDLINE | ID: mdl-37926962

ABSTRACT

Efficient oil/water separation tackles various issues in occasions of oil leakage and oil discharge, such as environmental pollution, recollection of the oil, and saving the water. Herein, a compact superhydrophobic/superoleophilic graphitic carbon nitride nanolayer coated on carbon fiber networks (CNBA/CF) is designed and synthesized for efficient gravity-driven oil/water separation. The CNBA/CF shows excellent oil absorption and an impressive oil/water filtration separation performance. The flux reaches the state-of-art value of 4.29 × 105 L/m2/h for dichloromethane with separation efficiency up to 99%. Successive oil absorption tests, long-term filtration separation, and harsh conditions experiments confirm the remarkable separation and chemical structure stability of the CNBA/CF filter. Besides, the CNBA/CF demonstrates good photocatalytic antifouling ability thanks to the extended visible light absorption and improved charge separation. This work combines the material surface wettability modulation with a photocatalytic self-cleaning property in the fabrication of efficient oil/water separation materials while overcoming the filter fouling issue.

10.
J Oral Rehabil ; 51(5): 886-897, 2024 May.
Article in English | MEDLINE | ID: mdl-38151884

ABSTRACT

BACKGROUND: Botulinum toxin type A (BTX-A) is increasingly used to manage painful temporomandibular disorders (TMD). However, the effect of BTX-A on muscular TMD remains unclear. OBJECTIVE: To assess the efficacy, safety and optimal dose of BTX-A for treating TMD. METHODS: We conducted systematic literature searches in MEDLINE, Embase, Web of Science, ClinicalTrials.gov and Cochrane Library until March 2023. We extracted data from randomized controlled trials (RCTs) that evaluated the efficacy and safety of BTX-A in treating muscular TMD. We performed a meta-analysis using a random-effects model. RESULTS: Fifteen RCTs involving 504 participants met the inclusion criteria. BTX-A was significantly more effective than placebo in reducing pain intensity, as measured on a 0-10 scale, at 1 month (MD [95% CI] = -1.92 [-2.87, -0.98], p < .0001) and 6 months (MD [95% CI] -2.08, [-3.19 to -0.98]; p = .0002). A higher dosage of BTX-A (60-100 U bilaterally) was associated with a greater reduction in pain at 6 months (MD [95% CI] = -2.98 [-3.52, -2.44]; p < .001). BTX-A also resulted in decreased masseter muscle intensity (µV) (MD [95% CI] = -44.43 [-71.33, -17.53]; p = .001) at 1 month and occlusal force (kg) at 3 months (MD [95% CI] = -30.29 [-48.22 to -12.37]; p = .0009). There was no significant difference in adverse events between BTX-A and placebo. CONCLUSIONS: BTX-A is a safe and effective treatment for reducing pain and improving temporomandibular muscle and joint function in muscular TMD patients. A bilateral dose of 60-100 U might be an optimal choice for treating muscular TMD pain.

11.
Fa Yi Xue Za Zhi ; 40(1): 37-42, 2024 Feb 25.
Article in English, Zh | MEDLINE | ID: mdl-38500459

ABSTRACT

OBJECTIVES: To investigate the toxicokinetic differences of 3,4-methylenedioxy-N-methylamphetamine (MDMA) and its metabolite 4,5-methylene dioxy amphetamine (MDA) in rats after single and continuous administration of MDMA, providing reference data for the forensic identification of MDMA. METHODS: A total of 24 rats in the single administration group were randomly divided into 5, 10 and 20 mg/kg experimental groups and the control group, with 6 rats in each group. The experimental group was given intraperitoneal injection of MDMA, and the control group was given intraperitoneal injection of the same volume of normal saline as the experimental group. The amount of 0.5 mL blood was collected from the medial canthus 5 min, 30 min, 1 h, 1.5 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h after administration. In the continuous administration group, 24 rats were randomly divided into the experimental group (18 rats) and the control group (6 rats). The experimental group was given MDMA 7 d by continuous intraperitoneal injection in increments of 5, 7, 9, 11, 13, 15, 17 mg/kg per day, respectively, while the control group was given the same volume of normal saline as the experimental group by intraperitoneal injection. On the eighth day, the experimental rats were randomly divided into 5, 10 and 20 mg/kg dose groups, with 6 rats in each group. MDMA was injected intraperitoneally, and the control group was injected intraperitoneally with the same volume of normal saline as the experimental group. On the eighth day, 0.5 mL of blood was taken from the medial canthus 5 min, 30 min, 1 h, 1.5 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h after administration. Liquid chromatography-triple quadrupole tandem mass spectrometry was used to detect MDMA and MDA levels, and statistical software was employed for data analysis. RESULTS: In the single-administration group, peak concentrations of MDMA and MDA were reached at 5 min and 1 h after administration, respectively, with the largest detection time limit of 12 h. In the continuous administration group, peak concentrations were reached at 30 min and 1.5 h after administration, respectively, with the largest detection time limit of 10 h. Nonlinear fitting equations for the concentration ratio of MDMA and MDA in plasma and administration time in the single-administration group and continuous administration group were as follows: T=10.362C-1.183, R2=0.974 6; T=7.397 3C-0.694, R2=0.961 5 (T: injection time; C: concentration ratio of MDMA to MDA in plasma). CONCLUSIONS: The toxicokinetic data of MDMA and its metabolite MDA in rats, obtained through single and continuous administration, including peak concentration, peak time, detection time limit, and the relationship between concentration ratio and administration time, provide a theoretical and data foundation for relevant forensic identification.


Subject(s)
3,4-Methylenedioxyamphetamine , Amphetamines , N-Methyl-3,4-methylenedioxyamphetamine , Rats , Animals , Amphetamine , N-Methyl-3,4-methylenedioxyamphetamine/toxicity , 3,4-Methylenedioxyamphetamine/analysis , Toxicokinetics , Saline Solution
12.
Angew Chem Int Ed Engl ; 63(20): e202402663, 2024 05 13.
Article in English | MEDLINE | ID: mdl-38467568

ABSTRACT

Thielavin A (1) is a fungal depside composed of one 3-methylorsellinic acid and two 3,5-dimethylorsellinic acid units. It displays diverse biological activities. However, the mechanism underlying the assembly of the heterotrimeric structure of 1 remains to be clarified. In this study, we identified the polyketide synthase (PKS) involved in the biosynthesis of 1. This PKS, designated as ThiA, possesses an unusual domain organization with the C-methyltransferase (MT) domain situated at the C-terminus following the thioesterase (TE) domain. Our findings indicated that the TE domain is solely responsible for two rounds of ester bond formation, along with subsequent chain hydrolysis. We identified a plausible mechanism for TE-catalyzed reactions and obtained insights into how a single PKS can selectively yield a specific heterotrimeric product. In particular, the tandem acyl carrier protein domains of ThiA are critical for programmed methylation by the MT domain. Overall, this study highlighted the occurrence of highly optimized domain-domain communication within ThiA for the selective synthesis of 1, which can advance our understanding of the programming rules of fungal PKSs.


Subject(s)
Depsides , Polyketide Synthases , Polyketide Synthases/metabolism , Polyketide Synthases/chemistry , Depsides/metabolism , Depsides/chemistry
13.
Angew Chem Int Ed Engl ; 63(2): e202314266, 2024 Jan 08.
Article in English | MEDLINE | ID: mdl-37940614

ABSTRACT

Co-based metal-organic frameworks (MOFs) as electrocatalysts for two-electron oxygen reduction reaction (2e- ORR) are highly promising for H2 O2 production, but suffer from the intrinsic activity-selectivity trade-off. Herein, we report a ZnCo bimetal-triazole framework (ZnCo-MTF) as high-efficiency 2e- ORR electrocatalysts. The experimental and theoretical results demonstrate that the coordination between 1,2,3-triazole and Co increases the antibonding-orbital occupancy on the Co-N bond, promoting the activation of Co center. Besides, the adjacent Zn-Co sites on 1,2,3-triazole enable an asymmetric "side-on" adsorption mode of O2 , favoring the reduction of O2 molecules and desorption of OOH* intermediate. By virtue of the unique ligand effect, the ZnCo-MTF exhibits a 2e- ORR selectivity of ≈100 %, onset potential of 0.614 V and H2 O2 production rate of 5.55 mol gcat -1 h-1 , superior to the state-of-the-art zeolite imidazole frameworks. Our work paves the way for the design of 2e- ORR electrocatalysts with desirable coordination and electronic structure.

14.
Angew Chem Int Ed Engl ; 63(23): e202403585, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38565432

ABSTRACT

In spite of the competitive performance at room temperature, the development of sodium-ion batteries (SIBs) is still hindered by sluggish electrochemical reaction kinetics and unstable electrode/electrolyte interphase under subzero environments. Herein, a low-concentration electrolyte, consisting of 0.5M NaPF6 dissolving in diethylene glycol dimethyl ether solvent, is proposed for SIBs working at low temperature. Such an electrolyte generates a thin, amorphous, and homogeneous cathode/electrolyte interphase at low temperature. The interphase is monolithic and rich in organic components, reducing the limitation of Na+ migration through inorganic crystals, thereby facilitating the interfacial Na+ dynamics at low temperature. Furthermore, it effectively blocks the unfavorable side reactions between active materials and electrolytes, improving the structural stability. Consequently, Na0.7Li0.03Mg0.03Ni0.27Mn0.6Ti0.07O2//Na and hard carbon//Na cells deliver a high capacity retention of 90.8 % after 900 cycles at 1C, a capacity over 310 mAh g-1 under -30 °C, respectively, showing long-term cycling stability and great rate capability at low temperature.

15.
Angew Chem Int Ed Engl ; : e202407228, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38975669

ABSTRACT

Three functionalized thienopyrazines (TPs), TP-MN (1), TP-CA (2), and TPT-MN (3) were designed and synthesized as self-assembled monolayers (SAMs) deposited on the NiOx film for tin-perovskite solar cells (TPSCs). Thermal, optical, electrochemical, morphological, crystallinity, hole mobility, and charge recombination properties, as well as DFT-derived energy levels with electrostatic surface potential mapping of these SAMs, have been thoroughly investigated and discussed. The structure of the TP-MN (1) single crystal was successfully grown and analyzed to support the uniform SAM produced on the ITO/NiOx substrate. When we used NiOx as HTM in TPSC, the device showed poor performance. To improve the efficiency of TPSC, we utilized a combination of new organic SAMs with NiOx HTM, the TPSC device exhibited the highest PCE of 7.7% for TP-MN (1). Hence, the designed NiOx/TP-MN (1) acts as a new model system for the development of efficient SAM-based TPSC. To the best of our knowledge, the combination of organic SAMs with anchoring CN/CN or CN/COOH groups, and NiOx HTM for TPSC has never been reported elsewhere. The TPSC device based on the NiOx/TP-MN bilayer exhibits great enduring stability for performance, retaining ~80% of its original value for shelf storage over 4000 h.

16.
J Am Chem Soc ; 145(20): 11293-11300, 2023 05 24.
Article in English | MEDLINE | ID: mdl-37172192

ABSTRACT

Alkyl salicylaldehyde derivatives are polyketide natural products, which are widely distributed in fungi and exhibit great structural diversity. Their biosynthetic mechanisms have recently been intensively studied; however, how the polyketide synthases (PKSs) involved in the fungal alkyl salicylaldehyde biosyntheses release their products remained elusive. In this study, we discovered an orphan biosynthetic gene cluster of salicylaldehyde derivatives in the fungus Stachybotrys sp. g12. Intriguingly, the highly reducing PKS StrA, encoded by the gene cluster, performs a reductive polyketide chain release, although it lacks a C-terminal reductase domain, which is typically required for such a reductive release. Our study revealed that the chain release is achieved by the ketoreductase (KR) domain of StrA, which also conducts cannonical ß-keto reductions during polyketide chain elongation. Furthermore, we found that the cupin domain-containing protein StrC plays a critical role in the aromatization reaction. Collectively, we have provided an unprecedented example of a KR domain-catalyzed polyketide chain release and a clearer image of how the salicylaldehyde scaffold is generated in fungi.


Subject(s)
Polyketides , Polyketide Synthases/metabolism , Aldehydes , Catalysis
17.
Mol Psychiatry ; 27(10): 4077-4091, 2022 10.
Article in English | MEDLINE | ID: mdl-35804093

ABSTRACT

Fear extinction allows for adaptive control of learned fear responses but often fails, resulting in a renewal or spontaneous recovery of the extinguished fear, i.e., forgetting of the extinction memory readily occurs. Using an activity-dependent neuronal labeling strategy, we demonstrate that engram neurons for fear extinction memory are dynamically positioned in the medial prefrontal cortex (mPFC), basolateral amygdala (BLA), and ventral hippocampus (vHPC), which constitute an engram construct in the term of directional engram synaptic connectivity from the BLA or vHPC to mPFC, but not that in the opposite direction, for retrieval of extinction memory. Fear renewal or spontaneous recovery switches the extinction engram construct from an accessible to inaccessible state, whereas additional extinction learning or optogenetic induction of long-term potentiation restores the directional engram connectivity and prevents the return of fear. Thus, the plasticity of engram construct underlies forgetting of extinction memory.


Subject(s)
Basolateral Nuclear Complex , Extinction, Psychological , Extinction, Psychological/physiology , Fear/physiology , Prefrontal Cortex/physiology , Conditioning, Psychological/physiology , Basolateral Nuclear Complex/physiology
18.
World J Urol ; 41(9): 2443-2449, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37495748

ABSTRACT

PURPOSE: To establish a parameter-based grading system for evaluating bladder trabeculation (BT). MATERIALS AND METHODS: A retrospective analysis was conducted on children diagnosed with posterior urethral valve (PUV) or neurogenic bladder (NB) who underwent voiding cystourethrogram (VCUG), urodynamic testing, and urological ultrasonography between January 2016 and October 2022. Cases involving urologic surgery, secondary bladder pathology, and an interval of more than 12 months between examinations were excluded. A parameter named Bladder Dispersion (BD) was calculated through fluoroscopic images, and the grading system was developed as follows: BD < 40 (Grade 0), 40 ≤ BD < 60 (Grade 1), 60 ≤ BD < 90 (Grade 2), BD ≥ 90 (Grade 3). Grades 0-1 were classified as low-risk group, while grades 2-3 were classified as high-risk group. Analysis of variance, Kruskal-Wallis test, and Chi-square test were performed to compare urodynamic results and complications across different grades and groups. RESULTS: A total of 74 patients were eligible to participate, which included 46 boys (62.2%) and 28 girls (37.8%), the mean age was 75.18 ± 48.39 months. Among them, 11 (14.9%) were PUV, 50 (67.6%) were NB, and 13 (17.5%) were PUV and NB. Significant differences were observed in maximum detrusor pressure, post-void residual urine ratio, and compliance among grades 0-3. Severe hydronephrosis and histories of urinary tract infection were more prevalent in the high-risk group. CONCLUSION: A reliable grading system with objective standards was proposed which could aid in the assessment of BT severity.


Subject(s)
Urethral Obstruction , Urinary Bladder Diseases , Urinary Bladder, Neurogenic , Urinary Retention , Male , Child , Female , Humans , Child, Preschool , Urinary Bladder/surgery , Retrospective Studies , Urinary Bladder Diseases/complications , Urinary Bladder, Neurogenic/diagnosis , Urinary Bladder, Neurogenic/complications , Urethral Obstruction/complications , Urodynamics
19.
BMC Gastroenterol ; 23(1): 47, 2023 Feb 23.
Article in English | MEDLINE | ID: mdl-36823614

ABSTRACT

BACKGROUND: The COVID-19 pandemic has impacted endoscopic training of the Narrow Band Imaging International Colorectal Endoscopic (NICE) classification, which could accurately predict pathology of colorectal polyps. This study aimed to evaluate the diagnostic performance by trainees of self-driven training vs. interactive training in the prediction of colorectal polyp histology. METHODS: This was a prospective randomized controlled study at five academic centers from January 1, 2021 to May 31, 2021. Trainees with no previous formal training of narrow band imaging or blue light imaging for prediction of colorectal polyp histology were randomly allocated to the self-driven training group or interactive training group. Before and after the training, all trainees were given 20 selected cases of colorectal polyp for testing. Their diagnostic performance was analyzed. RESULTS: Overall, the two training groups showed similar accuracy of NICE classification (79.3% vs. 78.1%; P = 0.637), vessel analysis (77.8% vs. 77.6%, P = 0.939), and surface pattern analysis (78.1% vs. 76.9%, P = 0.616). The accuracy of color analysis in the interactive training group was better (74.4% vs. 80.0%, P = 0.027). For high-confidence predictions, the self-driven training group showed higher accuracy of NICE classification (84.8% vs. 78.7%, P < 0.001) but no difference for analysis of color (79.6% vs. 81.0%), vessel pattern (83.0% vs. 78.5%), and surface pattern (81.8% vs. 78.5%). CONCLUSIONS: Overall, self-driven training showed comparable accuracy of NICE classification, vessel pattern, and surface pattern to interactive training, but lower accuracy of color analysis. This method showed comparable effectiveness and is more applicable than interactive training. It is worth spreading during the COVID-19 pandemic. Trial registration Name of the registry: Chinese Clinical Trial Registry, Trial registration number: ChiCTR2000031659, Date of registration: 06/04/2020, URL of trial registry record: http://www.chictr.org.cn/showproj.aspx?proj=51994.


Subject(s)
COVID-19 , Colonic Polyps , Colorectal Neoplasms , Humans , Colonic Polyps/diagnosis , Colonic Polyps/pathology , Colonoscopy/methods , Prospective Studies , Pandemics , Narrow Band Imaging/methods , Colorectal Neoplasms/pathology
20.
J Immunol ; 206(5): 1088-1101, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33495235

ABSTRACT

The skin of vertebrates is the outermost organ of the body and serves as the first line of defense against external aggressions. In contrast to mammalian skin, that of teleost fish lacks keratinization and has evolved to operate as a mucosal surface containing a skin-associated lymphoid tissue (SALT). Thus far, IgT representing the prevalent Ig in SALT have only been reported upon infection with a parasite. However, very little is known about the types of B cells and Igs responding to bacterial infection in the teleost skin mucosa, as well as the inductive or effector role of the SALT in such responses. To address these questions, in this study, we analyzed the immune response of trout skin upon infection with one of the most widespread fish skin bacterial pathogens, Flavobacterium columnare This pathogen induced strong skin innate immune and inflammatory responses at the initial phases of infection. More critically, we found that the skin mucus of fish having survived the infection contained significant IgT- but not IgM- or IgD-specific titers against the bacteria. Moreover, we demonstrate the local proliferation and production of IgT+ B cells and specific IgT titers, respectively, within the SALT upon bacterial infection. Thus, our findings represent the first demonstration that IgT is the main Ig isotype induced by the skin mucosa upon bacterial infection and that, because of the large surface of the skin, its SALT probably represents a prominent IgT-inductive site in fish.


Subject(s)
B-Lymphocytes/immunology , Flavobacteriaceae Infections/immunology , Immunity, Mucosal/immunology , Immunoglobulins/immunology , Mucous Membrane/immunology , Oncorhynchus mykiss/immunology , Skin/immunology , Animals , Cell Proliferation/physiology , Fish Diseases/immunology , Fish Diseases/microbiology , Fish Proteins , Flavobacteriaceae Infections/microbiology , Flavobacterium/immunology , Immunity, Innate/immunology , Immunoglobulin Isotypes/immunology , Inflammation/immunology , Inflammation/microbiology , Lymphoid Tissue/immunology , Mucous Membrane/microbiology , Oncorhynchus mykiss/microbiology , Skin/microbiology
SELECTION OF CITATIONS
SEARCH DETAIL