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1.
Mitochondrial DNA B Resour ; 9(9): 1162-1165, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39234583

RESUMO

Dipterocarpus retusus Blume is an endangered species on the IUCN Red List. In this study, we reported the complete chloroplast (cp) genome of D. retusus (GenBank accession number: OP271853). The cp genome was 154,303 bp long, with a large single-copy (LSC) region of 85,586 bp and a small single-copy (SSC) region of 20,273 bp separated by a pair of inverted repeats (IRs) of 24,222 bp. It encodes 128 genes, including 84 protein-coding genes, 36 tRNA genes, and eight ribosomal RNA genes. We also reconstructed the cp genome phylogeny of Dipterocarpus, which indicated D. retusus was closely related with the sympatric species D. gracilis. This study may contribute valuable information to the phylogenetic relationships within the genus Dipterocarpus.

2.
Nat Commun ; 15(1): 7683, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39266507

RESUMO

Resistive memory devices feature drastic conductance change and fast switching dynamics. Particularly, nonvolatile bipolar switching events (set and reset) can be regarded as a unique nonlinear activation function characteristic of a hysteretic loop. Upon simultaneous activation of multiple rows in a crosspoint array, state change of one device may contribute to the conditional switching of others, suggesting an interactive network existing in the circuit. Here, we prove that a passive resistive switching circuit is essentially an attractor network, where the binary memory devices are artificial neurons while the pairwise voltage differences define an anti-symmetric weight matrix. An energy function is successfully constructed for this network, showing that every switching in the circuit would decrease the energy. Due to the nonvolatile hysteretic function, the energy change for bit flip in this network is thresholded, which is different from the classic Hopfield network. It allows more stable states stored in the circuit, thus representing a highly compact and efficient solution for associative memory. Network dynamics (towards stable states) and their modulations by external voltages have been demonstrated in experiment by 3-neuron and 4-neuron circuits.

3.
Abdom Radiol (NY) ; 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39299988

RESUMO

OBJECTIVE: To comprehensively evaluate the renal structure and function of patients with renal artery stenosis (RAS) using multiparametric magnetic resonance imaging (MRI), and analyze the correlation between magnetic resonance (MR) parameters and renal function. MATERIALS AND METHODS: Renal multiparametric MRI was conducted on 62 patients with RAS utilizing a Philips Ingenia CX 3.0 T MRI system. The scanning protocols encompassed arterial spin labeling, phase contrast MRI, diffusion weighted imaging, T1 mapping, and blood oxygen level-dependent MRI. All patients underwent radionuclide renal dynamic imaging to calculate the glomerular filtration rate (GFR) for assessing renal function. RESULTS: Most MR parameters were correlated with GFR: renal parenchymal volume (R = 0.603), whole kidney renal blood flow (RBF) (R = 0.192), renal cortical RBF (R = 0.294), renal artery mean velocity (R = 0.593), stroke volume (R = 0.599), mean flux (R = 0.629), renal cortical apparent diffusion coefficient (ADC) (R = 0.466), medullary ADC (R = 0.332), cortical T1 value (R = - 0.206), corticomedullary T1 difference (R = 0.204), cortical T2* value (R = 0.448), and medullary T2* value (R = 0.272). The best prediction model for GFR using multiparametric MRI was obtained, including renal PV, whole kidney RBF, cortical RBF, mean velocity, mean flux, and CMD T1. CONCLUSION: Multiparametric MRI is a novel noninvasive examination method that can effectively and comprehensively assess the renal structure and function of RAS.

4.
J Inflamm Res ; 17: 6039-6050, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39247841

RESUMO

Objective: Fasting blood glucose (FBG) is a recognized risk factor for Ischemic Stroke, but little research has examined the interaction among FBG, Platelet Distribution Width (PDW) and the severity of neuronal damage. Thus, the present study constructs a moderated mediation model aimed to elucidate the relationships among FBG, PDW, and NIHSS scores in patients with acute ischemic stroke (AIS). Methods: We conducted a cross-sectional study on 431 AIS patients. Upon hospital admission, we assessed the patients' NIHSS scores and collected blood samples to measure FBG and PDW levels. The relationship between FBG and NIHSS scores moderated by PDW was analyzed by linear curve fitting analysis, multiple linear regression analysis, and moderated mediation analysis respectively. Results: In the tertile grouping based on FBG, both PDW and NIHSS scores of AIS patients demonstrated an increase corresponding with rising levels of FBG (p<0.001 for both). Multiple linear regression analysis revealed that, the ß coefficients (95% CI) for the relationship between FBG and NIHSS scores were 1.49 (1.27-1.71, p<0.01) post-adjustment for potential confounders. The ß coefficients (95% CI) for the relationship between FBG and PDW were 0.02 (0.01-0.04, p<0.01) post-adjustment. Likewise, for the relationship between PDW and NIHSS scores, the ß coefficients (95% CI) were 4.33 (3.07-5.59, p<0.01) after adjustment. These positive association remained consistent in sensitivity analysis and hierarchical analysis. Smoothed plots suggested that there are linear relationships between FBG and PDW and NIHSS scores respectively. Further mediation analysis indicated that increased PDW significantly (p<0.01) mediated 5.91% of FBG-associated increased NIHSS scores. Conclusion: This study suggested that FBG levels were associated with NIHSS scores, and the FBG-associated neurological impairment may be partially mediated by PDW. These findings underscore the importance of monitoring FBG and PDW levels in AIS patients, potentially guiding risk intervention strategies.

5.
Phytochemistry ; 228: 114259, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39186996

RESUMO

A comprehensive phytochemical investigation of the flower buds and leaves/twigs of Heptacodium miconioides, a cultivated ornamental plant native to China and categorized as 'vulnerable', has led to the isolation of 45 structurally diverse compounds, which comprise 18 phenylpropanoids (1-4, 7-20), 11 pentacyclic triterpenoids (5, 6, 21-29), eight secoiridoid glycosides (30-37), three quinic acid derivatives (38-40), and a few miscellaneous components (41-45). Among them, (+)-α-intermedianol (1), (+)-holophyllol A (2), and (-)-pseudolarkaemin A (3) represent previously unreported enantiomeric lignans, while (+)-7'(R)-hydroxymatairesinol (4) is an undescribed naturally occurring lignan. Heptacoacids A (5) and B (6) are undescribed 24-nor-urs-28-oic acid derivatives. Their chemical structures were determined by 2D-NMR, supplemented by evidence from specific rotations and circular dichroism spectra. Given the uncertainty surrounding the systematic position of Heptacodium, integrative taxonomy (ITA), a method utilized to define contentious species, is applied. Chemotaxonomy, a vital aspect of ITA, becomes significant. By employing hierarchical clustering analysis (HCA) and syntenic pattern analysis methods, a taxonomic examination based on the major specialized natural products from the flower buds of H. miconioides and two other Caprifoliaceae plants (i.e., Lonicera japonica and Abelia × grandiflora) could offer enhanced understanding of the systematic placement of Heptacodium. Additionally, compounds 39 and 40 displayed remarkable inhibitory activities against ATP-citrate lyase (ACL), with IC50 values of 0.11 and 1.10 µM, respectively. In summary, the discovery of medical properties and refining systematic classification can establish a sturdy groundwork for conservation efforts aimed at mitigating species diversity loss while addressing human diseases.


Assuntos
Produtos Biológicos , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Produtos Biológicos/isolamento & purificação , Estrutura Molecular , Espécies em Perigo de Extinção , Plantas Medicinais/química , Folhas de Planta/química
6.
BMC Musculoskelet Disord ; 25(1): 673, 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39192266

RESUMO

OBJECTIVE: To evaluate the clinical effectiveness of antibiotic bone cement combined with the lobulated perforator flap based on the descending branch of the lateral circumflex femoral artery (d-LCFA) in the treatment of infected traumatic tissue defects in the foot, in accordance with the Enhanced Recovery after Surgery (ERAS) concept. METHODS: From December 2019 to November 2022, 10 patients with infected traumatic tissue defects of the foot were treated with antibiotic bone cement combined with the d-LCFA lobulated perforator flap. The cohort comprised 6 males and 4 females, aged 21 to 67 years. Initial infection control was achieved through debridement and coverage with antibiotic bone cement, requiring one debridement in nine cases and two debridements in one case. Following infection control, the tissue defects were reconstructed utilizing the d-LCFA lobulated perforator flap, with the donor site closed primarily. The flap area ranged from 12 cm×6 cm to 31 cm×7 cm. Postoperative follow-up included evaluation of flap survival, donor site healing, and ambulatory function of the foot. RESULTS: The follow-up period ranged from 7 to 24 months, averaging 14 months. Infection control was achieved successfully in all cases. The flaps exhibited excellent survival rates and the donor site healed by first intention. Based on the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale, pain and function were evaluated as excellent in 3 cases, good in 5 cases, and moderate in 2 cases. CONCLUSION: The application of antibiotic bone cement combined with the d-LCFA lobulated perforator flap is an effective treatment for infected traumatic tissue defects of the foot with the advantages of simplicity, high repeatability, and precise curative effects. The application of the d-LCFA lobulated perforator flap in wound repair causes minimal damage to the donor site, shortens hospital stays, lowers medical expenses, and accelerates patient rehabilitation, aligning with the ERAS concept. Therefore, it is a practice worth promoting in clinical use.


Assuntos
Antibacterianos , Cimentos Ósseos , Desbridamento , Artéria Femoral , Traumatismos do Pé , Retalho Perfurante , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Retalho Perfurante/irrigação sanguínea , Idoso , Antibacterianos/administração & dosagem , Antibacterianos/uso terapêutico , Traumatismos do Pé/cirurgia , Cimentos Ósseos/uso terapêutico , Artéria Femoral/cirurgia , Desbridamento/métodos , Adulto Jovem , Procedimentos de Cirurgia Plástica/métodos , Resultado do Tratamento , Lesões dos Tecidos Moles/cirurgia , Estudos Retrospectivos , Cicatrização
7.
Environ Pollut ; 361: 124715, 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39151784

RESUMO

Sulfamethoxazole (SMX) is one of major antibiotic contaminants in current aqueous environment. In this paper, waste loofah and melamine were co-carbonized to prepare biochar-doped g-C3N4 (CCN) by a one-pot method and then combined with Co2PMo11VO40 (CoPMoV) using a binder to obtain the novel polyoxometalates (POMs) photocatalytic composites (CCN/CoPMoV). The incorporation of CoPMoV dramatically reduced the photogenerated carrier recombination and led to a small band gap. Under visible light, the synergetic activation from biochar, g-C3N4 and POMs can remove 98.5% of SMX (k = 0.215 min-1) in the peroxymonosulfate (PMS) system within 20 min and keep its high stability with the degradation of 88.9% after five cycles. Multi-active sites from CCN/CoPMoV are contributed to develop the most active species of SO4-∙, ·OH, 1O2, and h+. The validity in the degradation of SMX makes CCN/CoPMoV a promising and potential material for the removal of aqueous pollutants in the future.

8.
Bioelectrochemistry ; 160: 108771, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38972158

RESUMO

MiRNA-21 is recognized as an important biological marker for the diagnosis, treatment, and prognosis of breast cancer. Here, we have created a nanochannel biosensor utilizing the duplex-specific nuclease (DSN) signal amplification strategy to achieve the detection of miRNAs. In this system, DNA as the capture probe was covalently immobilized on the surface of nanochannels, which hybridized with the target miRNA and forms RNA/DNA duplexes. DSN could cleave the probe DNA in RNA/DNA duplexes, recycling target miRNA, which may again hybridized with other DNA probes. After N cycles, most of the DNA probes had been cleaved, and the content of miRNA could be quantified by detecting changes in surface charge density. This biosensor can distinguish miR-21 from non-complementary miRNAs and one-base mismatched miRNAs, with reliable detection limits as low as 1 fM in PBS. In addition, we had successfully applied this method to analysis of total RNA samples in MCF-7 cells and HeLa cells, and the nanochannels had also shown excellent responsiveness and strong anti-interference ability. This new method is expected to contribute to miRNA detection in clinical diagnostics, providing a unique approach to detecting and distinguishing disease-associated molecules.


Assuntos
Técnicas Biossensoriais , MicroRNAs , MicroRNAs/análise , Técnicas Biossensoriais/métodos , Humanos , Células MCF-7 , Células HeLa , Limite de Detecção , Sondas de DNA/química , Hibridização de Ácido Nucleico
9.
J Geriatr Cardiol ; 21(5): 550-576, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38948894

RESUMO

Cardiovascular computed tomography angiography (CTA) is a widely used imaging modality in the diagnosis of cardiovascular disease. Advancements in CT imaging technology have further advanced its applications from high diagnostic value to minimising radiation exposure to patients. In addition to the standard application of assessing vascular lumen changes, CTA-derived applications including 3D printed personalised models, 3D visualisations such as virtual endoscopy, virtual reality, augmented reality and mixed reality, as well as CT-derived hemodynamic flow analysis and fractional flow reserve (FFRCT) greatly enhance the diagnostic performance of CTA in cardiovascular disease. The widespread application of artificial intelligence in medicine also significantly contributes to the clinical value of CTA in cardiovascular disease. Clinical value of CTA has extended from the initial diagnosis to identification of vulnerable lesions, and prediction of disease extent, hence improving patient care and management. In this review article, as an active researcher in cardiovascular imaging for more than 20 years, I will provide an overview of cardiovascular CTA in cardiovascular disease. It is expected that this review will provide readers with an update of CTA applications, from the initial lumen assessment to recent developments utilising latest novel imaging and visualisation technologies. It will serve as a useful resource for researchers and clinicians to judiciously use the cardiovascular CT in clinical practice.

10.
J Colloid Interface Sci ; 675: 139-149, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38968634

RESUMO

Transition metal selenides (TMS) have received much attention as anode materials for sodium-ion batteries (SIBs) because of their high theoretical capacity and excellent redox reversibility. However, their further development is constrained by the dissolution of transition metal ions and substantial volume changes experienced during cycling. Herein, the high-entropy Prussian blue analogues were selenized by the vapor infiltration method, resulting in the formation of a core-shell structured high-entropy selenides (HESe-6). The core-shell structure with voids and abundant selenium vacancies on the surface effectively mitigates bulk expansion and enhances electronic conductivity. Furthermore, the high-entropy property endows an ultra-stable crystal structure and inhibits the dissolution of metal ions. The ex-situ EIS and in-situ XRD results show that HESe-6 is able to be reversibly transformed into highly conductive ultrafine metal particles upon Na+ embedding, providing more Na+ reactive active sites. In addition, despite the incorporation of up to seven different elements, it exhibits minimal phase transitions during discharge/charge cycles, effectively mitigating stress accumulation. HESe-6 could retain an ultralong-term stability of 765.83 mAh g-1 after 1000 loops even at 1 A g-1. Furthermore, when coupled with the Na3V2(PO4)2O2F cathode, it maintains a satisfactory charge energy density of 303 Wh kg-1 after 300 cycles, which shows promising application prospect in the future.

11.
Zhen Ci Yan Jiu ; 49(6): 594-603, 2024 Jun 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38897803

RESUMO

OBJECTIVES: To observe the effect of electroacupuncture (EA) on behavior and hippocampal protein phosphorylation in rats with chronic fatigue syndrome (CFS), so as to explore its mechanisms underlying improvement of CFS. METHODS: Male SD rats were randomly divided into control, model and EA groups (n=12 rats in each group). The CFS model was established by chronic multifactor combined with stress stimulation (treadmill training + restraint stress + sleep disturbance + crowded environment). For rats of the EA group, EA (1 mA, frequency of 10 Hz) was applied to "Shenting" (GV24) (with an acupuncture needle penetrated from GV24 to "Baihui" ï¼»GV20ï¼½) and "Dazhui" (GV14) for 15 min, once daily for 28 days. After treatment, the body weight, food intake and water intake of rats in each group were observed. The fatigue degree of rats was evaluated by Semi-quantitative score observation table of the general condition of experimental rats.The open field test (OFT) was used to assess the rats'anxiety severity by detecting the total number of grid-crossing and the times of the central area entered in 5 min, and Morris water maze test was employed to assess the rats' learning-memory ability by detecting the escape latency in 1 min, and the times of the original platform quadrant crossing in 1 min. The hippocampaus was taken for phosphorylated Label-free quantitative proteomics analysis by using Maxquant technology based on full scan mode to calculate the integral of each peptide signal of liquid chromatography-mass spectrometry(LC-MS). The differentially-expressed proteins (>1.5 folds for up-regulation or <0.67 folds for down-regulation) were evaluated by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. RESULTS: Compared with the control group, the body weight, food intake, and the times of original-platform quadrant crossing of spatial exploring of Morris water maze test were significantly decreased (P<0.01, P<0.05) , and the score of general conditions, times of grid-crossing and center area-entering of OFT, and the escape latency of navigation task were apparently increased (P<0.01) in rats of the model group. After EA intervention, the decreased original-platform quadrant crossing, and the increased score of general conditions, times of grid-crossing and the escape latency of navigation task were all reversed (P<0.01, P<0.05). Outcomes of proteomics analysis indicated that compared with the model group, there were 297 differentially expressed peptide (48 up-regulated and 249 down-regulated) segments in the control group, and there were 245 differentially expressed peptide (185 up-regulated and 60 down-regulated) segments in the EA group, in which, 25 overlapping peptide segments were reversed after EA treatment, corresponding to 24 proteins, mainly involving cytoskeletal structure. GO function annotation analysis showed that the top three differentially expressed phosphorylated proteins involved in the effect of EA intervention were the actin filament polymerization, protein depolymerization and cytoskeletal tissue in the biological process, the actin binding, structural molecular activity and cytoskeletal protein binding in the molecular function, and the cytoskeleton, dendrites and dendritic trees in the cellular component, respectively. The KEGG pathway annotation analysis for differentially expressed phosphorylated proteins showed that theinsulin secretion, axon guidance, phosphatidylinositol signaling system and lysine biosynthesis, etc. were involved in the effect of EA intervention. CONCLUSIONS: EA of GV24-GV20 and GV14 can improve the general state, anxiety and learning-memory ability of CFS model rats, which may be related to its functions in regulating the hippocampal protein phosphorylation level, and repairing the structure and function of synapses in hippocampus.


Assuntos
Eletroacupuntura , Síndrome de Fadiga Crônica , Hipocampo , Ratos Sprague-Dawley , Animais , Masculino , Ratos , Hipocampo/metabolismo , Síndrome de Fadiga Crônica/terapia , Síndrome de Fadiga Crônica/metabolismo , Fosforilação , Humanos , Pontos de Acupuntura , Modelos Animais de Doenças
12.
Zhen Ci Yan Jiu ; 49(6): 641-649, 2024 Jun 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38897809

RESUMO

Acupuncture is an effective measure for treating type 2 diabetes mellitus (T2DM). Many studies have shown that acupuncture can reduce blood glucose in patients with T2DM, but its mechanism is still unclear. This review summarized the mechanism of acupuncture on T2DM, the mechanisms of acupuncture in treating T2DM is related to improving insulin resistance, regulating inflammation, promoting insulin secretion, improving lipid metabolism disorders, resisting oxidative stress, improving obesity, controlling intestinal flora, and regulating the nervous system. At the same time, this review also points out the lack of current relevant research and the future research directions to provide a reference for further exploring the mechanism of acupuncture hypoglycemic action.


Assuntos
Terapia por Acupuntura , Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/metabolismo , Animais , Resistência à Insulina , Glicemia/metabolismo , Insulina/metabolismo , Estresse Oxidativo
13.
Cereb Cortex ; 34(6)2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38869374

RESUMO

The central sulcus divides the primary motor and somatosensory cortices in many anthropoid primate brains. Differences exist in the surface area and depth of the central sulcus along the dorso-ventral plane in great apes and humans compared to other primate species. Within hominid species, there are variations in the depth and aspect of their hand motor area, or knob, within the precentral gyrus. In this study, we used post-image analyses on magnetic resonance images to characterize the central sulcus shape of humans, chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla), and orangutans (Pongo pygmaeus and Pongo abelii). Using these data, we examined the morphological variability of central sulcus in hominids, focusing on the hand region, a significant change in human evolution. We show that the central sulcus shape differs between great ape species, but all show similar variations in the location of their hand knob. However, the prevalence of the knob location along the dorso-ventral plane and lateralization differs between species and the presence of a second ventral motor knob seems to be unique to humans. Humans and orangutans exhibit the most similar and complex central sulcus shapes. However, their similarities may reflect divergent evolutionary processes related to selection for different positional and habitual locomotor functions.


Assuntos
Evolução Biológica , Gorilla gorilla , Hominidae , Imageamento por Ressonância Magnética , Córtex Motor , Pan troglodytes , Filogenia , Animais , Humanos , Masculino , Pan troglodytes/anatomia & histologia , Pan troglodytes/fisiologia , Gorilla gorilla/anatomia & histologia , Gorilla gorilla/fisiologia , Feminino , Córtex Motor/anatomia & histologia , Córtex Motor/fisiologia , Córtex Motor/diagnóstico por imagem , Hominidae/anatomia & histologia , Hominidae/fisiologia , Adulto , Mãos/fisiologia , Mãos/anatomia & histologia , Adulto Jovem , Pongo pygmaeus/anatomia & histologia , Pongo pygmaeus/fisiologia , Especificidade da Espécie , Pongo abelii/anatomia & histologia , Pongo abelii/fisiologia
14.
J Am Chem Soc ; 146(20): 14166-14173, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38717077

RESUMO

Inorganic fullerene clusters have attracted widespread attention due to their highly symmetrical geometric structures and intrinsic electronic properties. However, cage-like clusters composed of heavy metal elements with high symmetry are rarely reported, and their synthesis is also highly challenging. In this study, we present the synthesis of a [K2(Bi@Pd12@Bi20)]4- cluster that incorporates a {Bi20} cage with pseudo-Ih symmetry, making it the largest main group metal cluster compound composed of the bismuth element to date. Magnetic characterization and theoretical calculations suggest that the spin state of the overall cluster is a quartet. Quantum chemical calculations reveal that the [Bi20]3- cluster has a similar electronic configuration to C606- and the [Bi@Pd12@Bi20]6- cluster exhibits a unique open-shell aromatic character.

15.
J Am Chem Soc ; 146(22): 15473-15478, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38782032

RESUMO

The synthesis and characterization of a series of polyantimony anionic clusters are reported. The products [(NbCp)2Sb10]2-, [MSb13]3- (M = Ru/Fe), and [MSb15]3- (M = Ru/Fe) were isolated as either K(18-crown-6) or K([2.2.2]-crypt) salts. The Sb10 ring contained in the [(NbCp)2Sb10]2- cluster can be viewed as an extension of two envelope-like cyclo-Sb5 units and represents by far the largest monocyclic all-antimony species. The clusters [MSb13]3- and [MSb15]3- (M = Ru/Fe) illustrate the variability of crown-like Sb8 ring motifs and reveal the fusion of different antimony fragments featuring unique Sb-Sb chain-like units. The reported synthetic approaches involve the fabrication of a variety of distinctive polyantimony anionic clusters, enhancing our understanding of the coordination chemistry of heavier group 15 elements.

16.
ACS Omega ; 9(18): 20185-20195, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38737014

RESUMO

The absolute structures of a pair of infinite Na(H2O)4+-connected ε-Keggin-Al13 species (Na-ε-K-Al13) that were inversion structures and mirror images of each other were determined. Single crystals obtained by adding A2SO4 (A = Li, Na, K, Rb, or Cs) solution to NaOH-hydrolyzed AlCl3 solution were subjected to X-ray structure analyses. The statistical results for 36 single crystals showed that all the crystals had almost the same unit cell parameter, belonged to the same F4̅3m space group, and possessed the same structural formula [Na(H2O)4AlO4Al12(OH)24(H2O)12](SO4)4·10H2O. However, the crystals had two inverse absolute structures (denoted A and B), which had a crystallization ratio of 1:1. From Li+ to Cs+, with increasing volume of the cation coexisting in the mother solution, the degree of disorder of the four H2O molecules in the Na(H2O)4+ hydrated ion continuously decreased; they became ordered when the cation was Cs+. Absolute structures A and B are the first two infinite aluminum polycations connected by statistically occupied [(Na1/4)4(H2O)4]+ hydrated ions. The three-dimensional structure of the infinite Na-ε-K-Al13 species can be regarded as the assembly of finite ε-K-Al13 species linked by [(Na1/4)4(H2O)4]+ in a 1:1 ratio. In this assembly, each [(Na1/4)4(H2O)4]+ is connected to four ε-K-Al13 and each ε-K-Al13 is also connected to four [(Na1/4)4(H2O)4]+ in tetrahedral orientations to form a continuous rigid framework structure, which has an inverse spatial orientation between absolute structure A and B. This discovery clarifies that the ε-K-Al13 (or ε-K-GaAl12) species in Na[MO4Al12(OH)24(H2O)12](XO4)4·nH2O (M = Al, Ga; X = S, Se; n = 10-20) exists as discrete groups and deepens understanding of the formation and evolution process of polyaluminum species in forcibly hydrolyzed aluminum salt solution. The reason why Na+ statistically occupies the four sites was examined, and a formation and evolution mechanism of the infinite Na-ε-K-Al13 species was proposed.

17.
Extremophiles ; 28(2): 24, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598094

RESUMO

Alginate is an important polysaccharide that is abundant in the marine environments, including the Polar Regions, and bacterial alginate lyases play key roles in its degradation. Many reported alginate lyases show characteristics of cold-adapted enzymes, including relatively low temperature optimum of activities (Topt) and low thermal stabilities. However, the cold-adaption mechanisms of alginate lyases remain unclear. Here, we studied the cold-adaptation mechanisms of alginate lyases by comparing four members of the PL7 family from different environments: AlyC3 from the Arctic ocean (Psychromonas sp. C-3), AlyA1 from the temperate ocean (Zobellia galactanivorans), PA1167 from the human pathogen (Pseudomonas aeruginosa PAO1), and AlyQ from the tropic ocean (Persicobacter sp. CCB-QB2). Sequence comparison and comparative molecular dynamics (MD) simulations revealed two main strategies of cold adaptation. First, the Arctic AlyC3 and temperate AlyA1 increased the flexibility of the loops close to the catalytic center by introducing insertions at these loops. Second, the Arctic AlyC3 increased the electrostatic attractions with the negatively charged substrate by introducing a high portion of positively charged lysine at three of the insertions mentioned above. Furthermore, our study also revealed that the root mean square fluctuation (RMSF) increased greatly when the temperature was increased to Topt or higher, suggesting the RMSF increase temperature as a potential indicator of the cold adaptation level of the PL7 family. This study provided new insights into the cold-adaptation mechanisms of bacterial alginate lyases and the marine carbon cycling at low temperatures.


Assuntos
Alginatos , Simulação de Dinâmica Molecular , Humanos , Bacteroidetes , Carbono , Catálise
18.
Theranostics ; 14(6): 2622-2636, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38646657

RESUMO

Rationale: In recent years, nicotinamide adenine dinucleotide (NAD+) precursors (Npre) have been widely employed to ameliorate female reproductive problems in both humans and animal models. However, whether and how Npre plays a role in the male reproductive disorder has not been fully clarified. Methods: In the present study, a busulfan-induced non-obstructive azoospermic mouse model was used, and Npre was administered for five weeks following the drug injection, with the objective of reinstating spermatogenesis and fertility. Initially, we assessed the NAD+ level, germ cell types, semen parameters and sperm fertilization capability. Subsequently, testis tissues were examined through RNA sequencing analysis, ELISA, H&E, immunofluorescence, quantitative real-time PCR, and Western blotting techniques. Results: The results indicated that Npre restored normal level of NAD+ in blood and significantly alleviated the deleterious effects of busulfan (BU) on spermatogenesis, thereby partially reestablishing fertilization capacity. Transcriptome analysis, along with recovery of testicular Fe2+, GSH, NADPH, and MDA levels, impaired by BU, and the fact that Fer-1, an inhibitor of ferroptosis, restored spermatogenesis and semen parameters close to CTRL values, supported such possibility. Interestingly, the reduction in SIRT2 protein level by the specific inhibitor AGK2 attenuated the beneficial effects of Npre on spermatogenesis and ferroptosis by affecting PGC-1α and ACLY protein levels, thus suggesting how these compounds might confer spermatogenesis protection. Conclusion: Collectively, these findings indicate that NAD+ protects spermatogenesis against ferroptosis, probably through SIRT2 dependent mechanisms. This underscores the considerable potential of Npre supplementation as a feasible strategy for preserving or restoring spermatogenesis in specific conditions of male infertility and as adjuvant therapy to preserve male fertility in cancer patients receiving sterilizing treatments.


Assuntos
Bussulfano , Ferroptose , NAD , Sirtuína 2 , Espermatogênese , Animais , Bussulfano/farmacologia , Masculino , Espermatogênese/efeitos dos fármacos , Camundongos , NAD/metabolismo , Ferroptose/efeitos dos fármacos , Sirtuína 2/metabolismo , Sirtuína 2/genética , Modelos Animais de Doenças , Testículo/metabolismo , Testículo/efeitos dos fármacos , Azoospermia/tratamento farmacológico , Azoospermia/metabolismo , Azoospermia/induzido quimicamente
19.
J Am Chem Soc ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602511

RESUMO

Meroterpenoid clavilactones feature a unique benzo-fused ten-membered carbocyclic ring unit with an α,ß-epoxy-γ-lactone moiety, forming an intriguing 10/5/3 tricyclic nested skeleton. These compounds are good inhibitors of the tyrosine kinase, attracting a lot of chemical synthesis studies. However, the natural enzymes involved in the formation of the 10/5/3 tricyclic nested skeleton remain unexplored. Here, we identified a gene cluster responsible for the biosynthesis of clavilactone A in the basidiomycetous fungus Clitocybe clavipes. We showed that a key cytochrome P450 monooxygenase ClaR catalyzes the diradical coupling reaction between the intramolecular hydroquinone and allyl moieties to form the benzo-fused ten-membered carbocyclic ring unit, followed by the P450 ClaT that exquisitely and stereoselectively assembles the α,ß-epoxy-γ-lactone moiety in clavilactone biosynthesis. ClaR unprecedentedly acts as a macrocyclase to catalyze the oxidative cyclization of the isopentenyl to the nonterpenoid moieties to form the benzo-fused macrocycle, and a multifunctional P450 ClaT catalyzes a ten-electron oxidation to accomplish the biosynthesis of the 10/5/3 tricyclic nested skeleton in clavilactones. Our findings establish the foundation for the efficient production of clavilactones using synthetic biology approaches and provide the mechanistic insights into the macrocycle formation in the biosynthesis of fungal meroterpenoids.

20.
BMC Geriatr ; 24(1): 220, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38438862

RESUMO

OBJECTIVE: To analyse and discuss the association of gender differences with the risk and incidence of poststroke aphasia (PSA) and its types, and to provide evidence-based guidance for the prevention and treatment of poststroke aphasia in clinical practice. DATA SOURCES: Embase, PubMed, Cochrane Library and Web of Science were searched from January 1, 2002, to December 1, 2023. STUDY SELECTION: Including the total number of strokes, aphasia, the number of different sexes or the number of PSA corresponding to different sex. DATA EXTRACTION: Studies with missing data, aphasia caused by nonstroke and noncompliance with the requirements of literature types were excluded. DATA SYNTHESIS: 36 papers were included, from 19 countries. The analysis of 168,259 patients with stroke and 31,058 patients with PSA showed that the risk of PSA was 1.23 times higher in female than in male (OR = 1.23, 95% CI = 1.19-1.29, P < 0.001), with a prevalence of PSA of 31% in men and 36% in women, and an overall prevalence of 34% (P < 0.001). Analysis of the risk of the different types of aphasia in 1,048 patients with PSA showed a high risk in females for global, broca and Wenicke aphasia, and a high risk in males for anomic, conductive and transcortical aphasia, which was not statistically significant by meta-analysis. The incidence of global aphasia (males vs. females, 29% vs. 32%) and broca aphasia (17% vs 19%) were higher in females, and anomic aphasia (19% vs 14%) was higher in males, which was statistically significant (P < 0.05). CONCLUSIONS: There are gender differences in the incidence and types of PSA. The risk of PSA in female is higher than that in male.


Assuntos
Afasia , Acidente Vascular Cerebral , Feminino , Humanos , Masculino , Incidência , Afasia/diagnóstico , Afasia/epidemiologia , Afasia/etiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia , Cooperação do Paciente
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