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Sepsis arises from an uncontrolled inflammatory response triggered by infection or stress, accompanied by alteration in cellular energy metabolism, and a strong correlation exists between these factors. Alpha-ketoglutarate (α-KG), an intermediate product of the TCA cycle, has the potential to modulate the inflammatory response and is considered a crucial link between energy metabolism and inflammation. The scavenger receptor (SR-A5), a significant pattern recognition receptor, assumes a vital function in anti-inflammatory reactions. In the current investigation, we have successfully illustrated the ability of α-KG to mitigate inflammatory factors in the serum of septic mice and ameliorate tissue damage. Additionally, α-KG has been shown to modulate metabolic reprogramming and macrophage polarization. Moreover, our findings indicate that the regulatory influence of α-KG on sepsis is mediated through SR-A5. We also elucidated the mechanism by which α-KG regulates SR-A5 expression and found that α-KG reduced the N6-methyladenosine level of macrophages by up-regulating the m6A demethylase ALKBH5. α-KG plays a crucial role in inhibiting inflammation by regulating SR-A5 expression through m6A demethylation during sepsis. The outcomes of this research provide valuable insights into the relationship between energy metabolism and inflammation regulation, as well as the underlying molecular regulatory mechanism.
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The objectives of this study were to measure the chlorophyll fluorescence (ChlF) parameters of Barbula indica (Hook.) Spreng and Conocephalum conicum (L.) Dumort subjected to various light intensities (LI) as a reflection of their adaptability to their habitats. The electron transport rate (ETR) of all plants under 500 µmol m-2 s-1 photosynthetic photon flux density (PPFD) was significantly higher than other LI treatments, implying that these plants could be grown under a specific and optimal light intensity adapted to 500 PPFD conditions. As LI increased from 50 to 2,000 PPFD, we observed in all plants increased non-photochemical quenching (NPQ) and photo-inhibitory quenching (qI) and decreased photosystem II efficiency (ΦPSII), potential quantum efficiency of PSII (Fv/Fm), actual PSII efficiency (ΔF/Fm'%), and Fv/Fm%. In addition, energy-dependent quenching (qE), the light protection system (qE + qZ + qT), and qI increased as ΦPSII decreased and photo-inhibition% increased under 1000, 1500, and 2000 PPFD conditions, suggesting that these plants had higher photo-protective ability under high LI treatments to maintain higher photosynthetic system performance. B. indica plants remained photochemically active and maintained higher qE under 300, 500, and 1000 PPFD, whereas C. conicum qZ + qT exhibited higher photo-protection under 500, 1000, and 1500 PPFD conditions. These ChlF indices can be used for predicting photosynthetic responses to light induction in different bryophytes and provide a theoretical basis for ecological monitoring.
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Clorofila , Hojas de la Planta , Clorofila/fisiología , Hojas de la Planta/fisiología , Fotosíntesis , Luz , Transporte de Electrón , Complejo de Proteína del Fotosistema II/metabolismoRESUMEN
Photoinduced electron-transfer (PET) immunoassay based on a fluorescence site-specifically labeled nanobody, also called mini Quenchbody (Q-body), exhibits extraordinary sensitivity and saves much time in the homogeneous noncompetitive mode and is therefore regarded as a valuable method. However, limited by the efficiency of both quenching and dequenching of the fluorescence signal before and after antigen binding associated with the PET principle, not all original nanobodies can be used as candidates for mini Q-bodies. Herein, with the anti-quinalphos nanobody 11A (Nb-11A) as the model, we, for the first time, adopt a strategy by combining X-ray structural analysis with site-directed mutagenesis to design and produce a mutant Nb-R29W, and then successfully generate a mini Q-body by labeling with ATTO520 fluorescein. Based on this, a novel PET immunoassay is established, which exhibits a limit of detection of 0.007 µg/mL with a detection time of only 15 min, 25-fold improved sensitivity, and faster by 5-fold compared to the competitive immunoassay. Meanwhile, the recovery test of vegetable samples and validation by the standard ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) both demonstrated that the established PET immunoassay is a novel, sensitive, and accurate detection method for quinalphos. Ultimately, the findings of this work will provide valuable insights into the development of triggered PET fluorescence probes by using existing antibody resources.
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Colorantes Fluorescentes , Espectrometría de Masas en Tándem , Cromatografía Liquida , Colorantes Fluorescentes/química , Inmunoensayo/métodos , Antígenos , Tomografía de Emisión de PositronesRESUMEN
Nanobodies (Nbs) have great potential in immunoassays due to their exceptional physicochemical properties. With the immortal nature of Nbs and the ability to manipulate their structures using protein engineering, it will become increasingly valuable to understand what structural features of Nbs drive high stability, affinity, and selectivity. Here, we employed an anti-quinalphos Nb as a model to illustrate the structural basis of Nbs' distinctive physicochemical properties and the recognition mechanism. The results indicated that the Nb-11A-ligand complexes exhibit a "tunnel" binding mode formed by CDR1, CDR2, and FR3. The orientation and hydrophobicity of small ligands are the primary determinants of their diverse affinities to Nb-11A. In addition, the primary factors contributing to Nb-11A's limited stability at high temperatures and in organic solvents are the rearrangement of the hydrogen bonding network and the enlargement of the binding cavity. Importantly, Ala 97 and Ala 34 at the active cavity's bottom and Arg 29 and Leu 73 at its entrance play vital roles in hapten recognition, which were further confirmed by mutant Nb-F3. Thus, our findings contribute to a deeper understanding of the recognition and stability mechanisms of anti-hapten Nbs and shed new light on the rational design of novel haptens and directed evolution to produce high-performance antibodies.
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Anticuerpos de Dominio Único , HaptenosRESUMEN
The majority of melanoma patients experience relapse during adjuvant therapy or after the end of therapy. Sixty-one patients from 3 melanoma centres who experienced recurrence and received adjuvant pembrolizumab for resected stage III/IV melanoma were enrolled. Disease characteristics, recurrence characteristics, subsequent management and outcomes were retrospectively analysed. Sixty-one patients were enrolled in this study. The median time to first relapse from the commencement of adjuvant pembrolizumab was 8 months (1-22 months). The first recurrences were locoregional alone in 25 patients (41%), distant alone in 29 (47.5%) and concurrent locoregional and distant relapse in 7 (11.5%). At the first recurrence, 4 patients (80%) who underwent resection alone experienced further relapse of disease. Three (60%) patients who were treated with adjuvant pembrolizumab following surgery, 2 (100%) patients who were treated with adjuvant chemotherapy, 2 (66.7%) patients who were treated with adjuvant chemotherapy and pembrolizumab combined and 3 (100%) patients who were treated with adjuvant radiotherapy and pembrolizumab combined had further recurrence. Of the three patients treated with adjuvant BRAF/MEKi following the first relapse, none had yet recurred. Of the 8 patients treated with pembrolizumab alone, only one patient (12.5%) who recurred after ceasing adjuvant PD1 had a partial response. The overall response rate to BRAF/MEKi was 75%, 3/4; to pembrolizumab in combination with an oral multitargeted receptor tyrosine kinase inhibitor, it was 22.2%, 2/9; to chemotherapeutic agents alone, it was 33.3%, 1/3; and to chemotherapeutic agents combined with pembrolizumab, it was 37.5%, 3/8. The patient treated with imatinib had progressive disease after 3 months of treatment. Of the 6 patients who received temozolomide combined with pembrolizumab, 3 (3/6, 50%) had a partial response. The median OS of the patients who relapsed locoregionally only was longer than that of the patients who relapsed distally at the first recurrence (35 months and 14 months, respectively; P < 0.01). The outcomes of the patients with disease recurrence during or after the completion of 1 year of adjuvant anti-PD1 therapy were poor despite multimodality treatment.
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Melanoma , Terapia Recuperativa , Neoplasias Cutáneas , Humanos , Adyuvantes Inmunológicos/uso terapéutico , Estudios de Cohortes , Pueblos del Este de Asia , Melanoma/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Proteínas Proto-Oncogénicas B-raf , Estudios Retrospectivos , Neoplasias Cutáneas/tratamiento farmacológico , Melanoma Cutáneo MalignoRESUMEN
It is often expected that Zn decreases Cd accumulation in plants due to competition for the same transporters. Here, we found that increasing Zn supply markedly increased the root-to-shoot translocation of Cd in rice. RNA sequencing showed that high Zn up-regulated expression of genes involved in glutathione biosynthesis and metabolism and the Zn/Cd transporter gene OsHMA2, but down-regulated expression of genes related to Zn uptake. Knockout of the iron or Zn transporter genes OsIRT1, OsIRT2, or OsZIP9 did not affect the Zn promotional effect on Cd translocation. Knockout of the manganese/Cd transporter gene OsNRAMP5 greatly reduced Cd uptake but did not affect the Zn promotional effect. Variation in the tonoplast transporter gene OsHMA3 affected Cd translocation but did not change the Zn promotional effect. Knockout of the Zn/Cd transporter gene OsHMA2 not only decreased Cd and Zn translocation, but also abolished the Zn promotional effect. Increased expression of OsHMA2 under high Zn conditions supports the hypothesis that this transporter participates in the promotional effect of Zn on Cd translocation. The results also show that OsIRT1, OsIRT2, and OsZIP9 made only small contributions to Cd uptake under low Zn conditions but not under high Zn conditions, whereas the dominant role of OsNRAMP5 in Cd uptake diminished under low Zn conditions.
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Cadmio , Oryza , Cadmio/metabolismo , Zinc/metabolismo , Oryza/genética , Oryza/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Transporte Biológico , Translocación Genética , Raíces de Plantas/genética , Raíces de Plantas/metabolismoRESUMEN
Background: Hypoperfusion, a common manifestation of many critical illnesses, could lead to abnormalities in body surface thermal distribution. However, the interpretation of thermal images is difficult. Our aim was to assess the mortality risk of critically ill patients at risk of hypoperfusion in a prospective cohort by infrared thermography combined with deep learning methods. Methods: This post-hoc study was based on a cohort at high-risk of hypoperfusion. Patients' legs were selected as the region of interest. Thermal images and conventional hypoperfusion parameters were collected. Six deep learning models were attempted to derive the risk of mortality (range: 0 to 100%) for each patient. The area under the receiver operating characteristic curve (AUROC) was used to evaluate predictive accuracy. Results: Fifty-five hospital deaths occurred in a cohort consisting of 373 patients. The conventional hypoperfusion (capillary refill time and diastolic blood pressure) and thermal (low temperature area rate and standard deviation) parameters demonstrated similar predictive accuracies for hospital mortality (AUROC 0.73 and 0.77). The deep learning methods, especially the ResNet (18), could further improve the accuracy. The AUROC of ResNet (18) was 0.94 with a sensitivity of 84% and a specificity of 91% when using a cutoff of 36%. ResNet (18) presented a significantly increasing trend in the risk of mortality in patients with normotension (13 [7 to 26]), hypotension (18 [8 to 32]) and shock (28 [14 to 62]). Conclusions: Interpreting infrared thermography with deep learning enables accurate and non-invasive assessment of the severity of patients at risk of hypoperfusion.
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RATIONALE: Hemorrhagic complications represent a major limitation of intravenous thrombolysis using tPA (tissue-type plasminogen activator) in patients with ischemic stroke. The expression of tPA receptors on immune cells raises the question of what effects tPA exerts on these cells and whether these effects contribute to thrombolysis-related hemorrhagic transformation. OBJECTIVE: We aim to determine the impact of tPA on immune cells and investigate the association between observed immune alteration with hemorrhagic transformation in ischemic stroke patients and in a rat model of embolic stroke. METHODS AND RESULTS: Paired blood samples were collected before and 1 hour after tPA infusion from 71 patients with ischemic stroke. Control blood samples were collected from 27 ischemic stroke patients without tPA treatment. A rat embolic middle cerebral artery occlusion model was adopted to investigate the underlying mechanisms of hemorrhagic transformation. We report that tPA induces a swift surge of circulating neutrophils and T cells with profoundly altered molecular features in ischemic stroke patients and a rat model of focal embolic stroke. tPA exacerbates endothelial injury, increases adhesion and migration of neutrophils and T cells, which are associated with brain hemorrhage in rats subjected to embolic stroke. Genetic ablation of annexin A2 in neutrophils and T cells diminishes the effect of tPA on these cells. Decoupling the interaction between mobilized neutrophils/T cells and the neurovascular unit, achieved via a S1PR (sphingosine-1-phosphate receptor) 1 modulator RP101075 and a CCL2 (C-C motif chemokine ligand 2) synthesis inhibitor bindarit, which block lymphocyte egress and myeloid cell recruitment, respectively, attenuates hemorrhagic transformation and improves neurological function after tPA thrombolysis. CONCLUSIONS: Our findings suggest that immune invasion of the neurovascular unit represents a previously unrecognized mechanism underlying tPA-mediated brain hemorrhage, which can be overcome by precise immune modulation during thrombolytic therapy.
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Accidente Cerebrovascular Embólico/tratamiento farmacológico , Fibrinolíticos/toxicidad , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Hemorragias Intracraneales/inducido químicamente , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Neutrófilos/efectos de los fármacos , Linfocitos T/efectos de los fármacos , Terapia Trombolítica , Activador de Tejido Plasminógeno/toxicidad , Animales , Anexina A2/metabolismo , Línea Celular , Quimiocina CCL2/metabolismo , Quimiotaxis de Leucocito/efectos de los fármacos , Modelos Animales de Enfermedad , Accidente Cerebrovascular Embólico/sangre , Accidente Cerebrovascular Embólico/inmunología , Femenino , Fibrinolíticos/administración & dosificación , Humanos , Infarto de la Arteria Cerebral Media/sangre , Infarto de la Arteria Cerebral Media/inmunología , Infusiones Intravenosas , Hemorragias Intracraneales/sangre , Hemorragias Intracraneales/inmunología , Accidente Cerebrovascular Isquémico/sangre , Accidente Cerebrovascular Isquémico/inmunología , Masculino , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/inmunología , Neutrófilos/metabolismo , Ratas Wistar , Receptores de Esfingosina-1-Fosfato/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Activador de Tejido Plasminógeno/administración & dosificaciónRESUMEN
UDP-glucose ceramide glucosyltransferase (UGCG) is the first key enzyme in glycosphingolipid (GSL) metabolism that produces glucosylceramide (GlcCer). Increased UGCG synthesis is associated with cell proliferation, invasion and multidrug resistance in human cancers. In this study we investigated the role of UGCG in the pathogenesis of hepatic fibrosis. We first found that UGCG was over-expressed in fibrotic livers and activated hepatic stellate cells (HSCs). In human HSC-LX2 cells, inhibition of UGCG with PDMP or knockdown of UGCG suppressed the expression of the biomarkers of HSC activation (α-SMA and collagen I). Furthermore, pretreatment with PDMP (40 µM) impaired lysosomal homeostasis and blocked the process of autophagy, leading to activation of retinoic acid signaling pathway and accumulation of lipid droplets. After exploring the structure and key catalytic residues of UGCG in the activation of HSCs, we conducted virtual screening, molecular interaction and molecular docking experiments, and demonstrated salvianolic acid B (SAB) from the traditional Chinese medicine Salvia miltiorrhiza as an UGCG inhibitor with an IC50 value of 159 µM. In CCl4-induced mouse liver fibrosis, intraperitoneal administration of SAB (30 mg · kg-1 · d-1, for 4 weeks) significantly alleviated hepatic fibrogenesis by inhibiting the activation of HSCs and collagen deposition. In addition, SAB displayed better anti-inflammatory effects in CCl4-induced liver fibrosis. These results suggest that UGCG may represent a therapeutic target for liver fibrosis; SAB could act as an inhibitor of UGCG, which is expected to be a candidate drug for the treatment of liver fibrosis.
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Células Estrelladas Hepáticas , Cirrosis Hepática , Ratones , Humanos , Animales , Simulación del Acoplamiento Molecular , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/metabolismo , Hígado/metabolismo , Colágeno Tipo I/metabolismoRESUMEN
Fifteen new diterpenoids, namely xishaklyanes A-O (1-15), along with three known related ones (16-18), were isolated from the soft coral Klyxum molle collected from Xisha Islands, South China Sea. The stereochemistry of the new compounds was elucidated by a combination of detailed spectroscopic analyses, chemical derivatization, quantum chemical calculations, and comparison with the reported data. The absolute configuration of compound 18 was established by the modified Mosher's method for the first time. In bioassay, some of these compounds exhibited considerable antibacterial activities on fish pathogenic bacteria, and compound 4 showed the most effective activity with MIC of 0.225 µg/mL against Lactococcus garvieae.
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Antozoos , Diterpenos , Animales , Antozoos/química , Diterpenos/química , China , Antibacterianos/farmacología , Estructura MolecularRESUMEN
Cardiac hypertrophy, a kind of cardiomyopathic abnormality, might trigger heart contractile and diastolic dysfunction, and even heart failure. Currently, bisphenols (BPs) including bisphenol A (BPA), and its alternatives bisphenol AF (BPAF), bisphenol F (BPF) and bisphenol S (BPS) are ubiquitously applied in various products and potentially possess high cardiovascular risks for humans. However, the substantial experimental evidences of BPs on heart function, and their structure-related effects on cardiomyocyte hypertrophy are still urgently needed. DNA methylation, a typical epigenetics, play key roles in BPs-induced transcription dysregulation, thereby affecting human health including cardiovascular system. Thus, in this study, we performed RNA-seq and reduced representation bisulfite sequencing (RRBS) to profile the landscapes of BPs-induced cardiotoxicity and to determine the key roles of DNA methylation in the transcription. Further, the capabilities of three BPA analogues, together with BPA, in impacting heart function and changing DNA methylation and transcription were compared. We concluded that similar to BPA, BPAF, BPF and BPS exposure deteriorated heart function in a mouse model, and induced cardiomyocyte hypertrophy in a H9c2 cell line. BPAF, BPF and BPS all played BPA-like roles in both transcriptive and methylated hierarchies. Moreover, we validated the expression levels of four cardiomyocyte hypertrophy related candidate genes, Psmc1, Piptnm2, Maz and Dusp18, which were all upregulated and with DNA hypomethylation. The findings on the induction of BPA analogues on cardiomyocyte hypertrophy and DNA methylation revealed their potential detrimental risks in heart function of humans.
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Epigénesis Genética , Epigenoma , Humanos , Animales , Ratones , Transcriptoma , Miocitos Cardíacos , HipertrofiaRESUMEN
Two new cembranoids, namely sarcoboettgerols D and E, together with four known related ones, have been isolated from the soft coral Sarcophyton boettgeri collected from Weizhou Island in the South China Sea. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance methods, time-dependent density functional theory-electronic circular dichroism calculations, as well as comparison with the reported data in the literature. A plausible biogenetic relationship of four cembranoids was proposed. In bioassays, sarcomililatin B exhibited cytotoxic activity against H1299â cell (IC50 =35.0â µM), whereas sarcomililatin B and sarcomililatin A displayed moderate antibacterial activities (MIC 17.4-34.8â µg/mL).
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Antozoos , Antineoplásicos , Diterpenos , Animales , Humanos , Antozoos/anatomía & histología , Antozoos/química , Antozoos/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Diterpenos/química , Diterpenos/farmacología , Espectroscopía de Resonancia Magnética , Estructura MolecularRESUMEN
The pro-inflammation M1 to anti-inflammation M2 macrophage ratio contribute to the severity of lipopolysaccharide (LPS)-induced acute lung injury (ALI). JMJD3 aggravates the inflammatory reaction through affecting epigenetic modification and macrophage's phenotype to deteriorate ALI. To explore the mechanism underlying the upregulation of the macrophage M1/M2 ratio through JMJD3, we developed an ALI mouse model using intratracheal LPS, LPS-stimulated RAW 264.7 cells, and inhibited JMJD3 using GSK-J4. H3K27me3 and H3K4me3 were investigated as JMJD3-mediated epigenetic alteration sites in vivo and in vitro. C/EBPß and KDM5A were validated as linking factors between H3K27 and H3K4. IL4i1 was investigated as a JMJD3-mediated targeted gene to regulate the macrophage M1/M2 ratio. Chromatin immunoprecipitation was used to evaluate the relationship between H3K27me3 and C/ebpß, C/EBPß and Kdm5a, H3K4me3 and Il4i1. Inhibiting JMJD3 with GSK-J4 can relieve inflammation and pathological performance in ALI. JMJD3 can reduce IL4i1 expression to increase the macrophage M1/M2 ratio and aggravated ALI which process was mediated via JMJD3-indcued H3K27me3 and H3K4me3 demethylation, latter H3K4me3 demethylation inhibited IL4i1 transcription. Inhibiting JMJD3 with GSK-J4 can increase IL4i1 expression, subsequently decreasing the expressions of M1 and increasing of M2 in vivo. The over-expression IL4i1 in LPS-stimulated macrophage or inhibiting JMJD3 with GSK-J4 can both reverse the increase of the macrophage M1/M2 ratio in vitro. C/EBPß and KDM5A were upregulated by LPS simulation, which linked JMJD3-induced H3K27-H3K4 demethylation. JMJD3 inhibited IL4i1 to increase the macrophage M1/M2 phenotype ratio and aggravate LPS-induced ALI. Using GSK-J4 to inhibit JMJD3 may facilitate the treatment of LPS-induced ALI.
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Histonas , Lipopolisacáridos , Lesión Pulmonar , Animales , Ratones , Desmetilación , Inflamación/metabolismo , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Lipopolisacáridos/farmacología , Lesión Pulmonar/genética , Lesión Pulmonar/metabolismoRESUMEN
PURPOSE: Data objectively comparing outcomes following pollicization versus toe-to-thumb transfer for reconstruction after traumatic thumb amputation in adults remains sparse. Given that this decision is reliant on personal preference, it is important to understand the subjective nature of these preferences, particularly in the context of culture. The purpose of this study was to compare Eastern and Western societal and hand surgeon preferences for pollicization versus toe-to-thumb transfer for traumatic thumb reconstruction. METHODS: Investigators from 6 international locations recruited local hand surgeons and members of the general population. Austria, Germany, the United States, and Spain were grouped as "Western" nations. China and India separately represented "Eastern" nations. Participants completed a questionnaire evaluating their personal preferences for pollicization and toe-to-thumb transfer. The questions posed to the general population and hand surgeons were identical. Demographic data were also collected. RESULTS: When comparing the Western nations, China, and India, there was no difference in personal preferences within the general population for pollicization versus toe-to-thumb transfer. In contrast, most Indian hand surgeons favored toe-to-thumb transfer and most Western surgeons were uncertain about which procedure they would favor. Surgeons had more optimistic expectations regarding postoperative hand function, new thumb sensation, and hand appearance following pollicization than the general population. Similarly, for toe-to-thumb transfer, a greater proportion of surgeons predicted good-to-excellent function, sensation, and appearance. CONCLUSIONS: There was no clear, observed "East" versus "West" difference in the general population's personal preferences for pollicization versus toe-to-thumb transfer among study participants. The members of the general population and hand surgeons had different outcome expectations. CLINICAL RELEVANCE: Understanding how culture influences patient and hand surgeon preferences for pollicization versus toe-to-thumb transfer may help guide future decision-making for traumatic thumb reconstruction.
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Cellobiose 2-epimerase (CE) is ideally suited to synthesize lactulose from lactose, but the poor thermostability and catalytic efficiency restrict enzymatic application. Herein, a non-characterized CE originating from Caldicellulosiruptor morganii (CmCE) was discovered in the NCBI database. Then, a smart mutation library was constructed based on FoldX ΔΔG calculation and modeling structure analysis, from which a positive mutant D226G located within the α8/α9 loop exhibited longer half-lives at 65-75 °C as well as lower Km and higher kcat/Km values compared with CmCE. Molecular modeling demonstrated that the improvement of D226G was largely attributed to the rigidification of the flexible loop, the compactness of the catalysis pocket and the increment of substrate-binding capability. Finally, the yield of synthesizing lactulose catalyzed by D226G reached 45.5%, higher than the 35.9% achieved with CmCE. The disclosed effect of the flexible loop on enzymatic stability and catalysis provides insight to redesign efficient CEs to biosynthesize lactulose.
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Lactosa , Lactulosa , Lactulosa/química , Lactosa/química , Celobiosa/química , Racemasas y Epimerasas/genética , Clostridiales , Diseño Asistido por ComputadoraRESUMEN
Plants take up a wide range of trace metals/metalloids (hereinafter referred to as trace metals) from the soil, some of which are essential but become toxic at high concentrations (e.g., Cu, Zn, Ni, Co), while others are non-essential and toxic even at relatively low concentrations (e.g., As, Cd, Cr, Pb, and Hg). Soil contamination of trace metals is an increasing problem worldwide due to intensifying human activities. Trace metal contamination can cause toxicity and growth inhibition in plants, as well as accumulation in the edible parts to levels that threatens food safety and human health. Understanding the mechanisms of trace metal toxicity and how plants respond to trace metal stress is important for improving plant growth and food safety in contaminated soils. The accumulation of excess trace metals in plants can cause oxidative stress, genotoxicity, programmed cell death, and disturbance in multiple physiological processes. Plants have evolved various strategies to detoxify trace metals through cell-wall binding, complexation, vacuolar sequestration, efflux, and translocation. Multiple signal transduction pathways and regulatory responses are involved in plants challenged with trace metal stresses. In this review, we discuss the recent progress in understanding the molecular mechanisms involved in trace metal toxicity, detoxification, and regulation, as well as strategies to enhance plant resistance to trace metal stresses and reduce toxic metal accumulation in food crops.
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Metaloides , Metales Pesados , Contaminantes del Suelo , Humanos , Metales Pesados/análisis , Metales Pesados/metabolismo , Metales Pesados/toxicidad , Metaloides/metabolismo , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Contaminantes del Suelo/toxicidad , Suelo/química , Plantas/metabolismoRESUMEN
OBJECTIVE: To evaluate the clinical outcomes of seminal vesiculoscopy-assisted thulium laser ablation (SVS-TLA) in the treatment of oligoasthenozoospermia or azoospermia induced by ejaculatory duct obstruction (EDO). METHODS: We retrospectively analyzed the clinical data on 42 cases of EDO-induced oligoasthenozoospermia or azoospermia in our Clinic of Andrology from April 2018 to January 2020, all definitely diagnosed and treated by SVS-TLA. We followed up the patients regularly after operation, obtained their routine semen parameters at 3, 6 and 9 months postoperatively, examined them by t-test and compared them with the baseline. RESULTS: Operations were successfully completed in all the 42 cases, with an average surgery time of 52.7 minutes. Compared with the routine semen parameters collected 2 weeks before surgery, the semen volume, sperm concentration and total sperm motility of the patients were all significantly improved at 3, 6 and 9 months postoperatively (P < 0.01). Sperm were found in 40 cases at 3 months and in the other 2 cases at 6 and 9 months after surgery. Postoperative complications were observed in 7 cases, including epididymitis, perineal or testicular pain, and hematuria, which all disappeared after corresponding symptomatic treatment. No such serious complications as retrograde ejaculation, rectal injury, urethral stricture or urinary incontinence occurred in any of the cases after operation. CONCLUSION: SVS-TLA is a safe and effective option for the treatment of EDO, which can significantly improve the semen quality of the patient without causing serious postoperative complications.
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Azoospermia , Terapia por Láser , Humanos , Masculino , Conductos Eyaculadores/cirugía , Azoospermia/cirugía , Análisis de Semen , Tulio , Vesículas Seminales/cirugía , Semen , Estudios Retrospectivos , Motilidad Espermática , Complicaciones Posoperatorias/cirugíaRESUMEN
Uridine diphosphate glycosyltransferase(UGT) is a highly conserved protein in plants, which usually functions in secondary metabolic pathways. This study used the Hidden Markov Model(HMM) to screen out members of UGT gene family in the whole genome of Dendrobium officinale, and 44 UGT genes were identified. Bioinformatics was used to analyze the structure, phylogeny, and promoter region components of D. officinale genes. The results showed that UGT gene family could be divided into four subfamilies, and UGT gene structure was relatively conserved in each subfamily, with nine conserved domains. The upstream promoter region of UGT gene contained a variety of cis-acting elements related to plant hormones and environmental factors, indicating that UGT gene expression may be induced by plant hormones and external environmental factors. UGT gene expression in different tissues of D. officinale was compared, and UGT gene expression was found in all parts of D. officinale. It was speculated that UGT gene played an important role in many tissues of D. officinale. Through transcriptome analysis of D. officinale mycorrhizal symbiosis environment, low temperature stress, and phosphorus deficiency stress, this study found that only one gene was up-regulated in all three conditions. The results of this study can help understand the functions of UGT gene family in Orchidaceae plants and provide a basis for further study on the molecular regulation mechanism of polysaccharide metabolism pathway in D. officinale.
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Dendrobium , Micorrizas , Dendrobium/genética , Reguladores del Crecimiento de las Plantas , Glicosiltransferasas/genética , Glicosiltransferasas/metabolismo , Perfilación de la Expresión Génica , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMEN
Represented herein is the first example of N-radical generation direct from N-H bond activation under mild and redox-neutral conditions. The in situ generated N-radical intercepts a reduced heteroarylnitrile/aryl halide for C-N bond formation under visible-light irradiation of quantum dots (QDs). A series of aryl and alkylamines with heteroarylnitriles/aryl halides exhibit high efficiency, site-selectivity and good functional-group tolerance. Moreover, consecutive C-C and C-N bond formation using benzylamines as substrates is also achieved, producing N-aryl-1,2-diamines with H2 evolution. The redox-neutral conditions, broad substrate scope, and efficiency of N-radical formation are advantageous for organic synthesis.
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A new way to form fluorenones via the direct excitation of substrates instead of photocatalyst to activate the C(sp2 )-H bond under redox-neutral condition is reported. Our design relies on the photoexcited aromatic aldehyde intermediates that can be intercepted by cobaloxime catalyst through single electron transfer for following ß-H elimination. The generation of acyl radical and successful interception by a metal catalyst cobaloxime avoid the use of a photocatalyst and stoichiometric external oxidants, affording a series of highly substituted fluorenones, including six-membered ketones, such as xanthone and thioxanthone derivatives in good to excellent yields, and with hydrogen as the only byproduct. This catalytic system features a readily available metal catalyst, mild reaction conditions and broad substrate scope, in which sunlight reaction and scale-up experiments by continuous-flow approach make the new methodology sustainable and amenable for potentially operational procedures.