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BACKGROUND: To investigate the association between perfusion deficit, vessel wall characteristics, and risk of recurrent ischemic events in medically treated patients with chronic symptomatic anterior circulation large vessel occlusion. METHODS: We retrospectively reviewed chronic symptomatic patients due to anterior circulation large vessel occlusion in our center. All patients received multiparametric magnetic resonance imaging (including perfusion-weighted imaging and high-resolution vessel wall imaging) within 4 weeks to 3 months after symptom onset. The association between baseline clinical or imaging variables and recurrent ischemic events was assessed in bivariate models and multivariable logistic regression to identify independent predictors of recurrence. RESULTS: Among 71 enrolled patients, 21.1% (15/71) patients had recurrent ischemic events (nine ischemic strokes and six transient ischemic attacks) during a 2-year follow-up. In bivariate models, hypertension, occlusion with hyperintense signals, the presence of intraluminal thrombus, Tmax >4 s volume, Tmax >6 s volume, Tmax >8 s volume, and Tmax >10 s volume were associated with recurrence (all p < 0.05). In multivariate analysis, hypertension (p = 0.039, OR 10.057 (95% CI, 1.123-90.048)), higher deficit volume of Tmax >4 s (p = 0.011, OR 1.012 (95% CI, 1.003-1.021)) and occlusion with hyperintense signal (p = 0.030, OR 6.732 (95% CI, 1.200-37.772)) were still independent predictors of recurrent ischemic events. CONCLUSIONS: Besides hypertension history, higher deficit volume of Tmax >4 s and occlusion with hyperintense signal determined using multiparametric MRI are strongly associated with risk for recurrent ischemic events in medically treated patients with chronic symptomatic anterior circulation large vessel occlusion. Future studies are needed to determine the utility of revascularization strategies in such high-risk patients.
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BACKGROUND: Previous epidemiologic investigations have consistently demonstrated a strong association between the ratio of cholesterol to total lipids in medium very-low-density lipoprotein (VLDL) and the occurrence of peptic ulcers (PU). However, the precise causal relationship between these factors remains ambiguous. Consequently, this study aims to elucidate the potential correlation between the ratio of cholesterol to total lipids in medium VLDL and the incidence of peptic ulcer. AIM: To investigate the ratio of cholesterol to total lipids in medium very-low-density lipoprotein (VLDL) association with PU via genetic methods, guiding future clinical research. METHODS: Genome-wide association study (GWAS) datasets for the ratio of cholesterol to total lipids in intermediate VLDL and peptic ulcer were retrieved from the IEU OpenGWAS project (https://gwas.mrcieu.ac.uk). For the forward Mendelian randomization (MR) analysis, 72 single nucleotide polymorphisms (SNPs) were identified as instrumental variables. These SNPs were selected based on their association with the ratio of cholesterol to total lipids in intermediate VLDL, with peptic ulcer as the outcome variable. Conversely, for the inverse MR analysis, no SNPs were identified with peptic ulcer as the exposure variable and the ratio of cholesterol to total lipids in intermediate VLDL as the outcome. All MR analyses utilized inverse variance weighted (IVW) as the primary analytical method. Additionally, weighted median and MR-Egger methods were employed as supplementary analytical approaches to assess causal effects. Egger regression was used as a supplementary method to evaluate potential directional pleiotropy. Heterogeneity and multiplicity tests were conducted using the leave-one-out method to evaluate result stability and mitigate biases associated with multiple testing. RESULTS: The genetically predicted ratio of cholesterol to total lipids in medium VLDL was significantly associated with an elevated risk of peptic ulcer (IVW: OR = 2.557, 95%CI = 1.274-5.132, P = 0.008). However, no causal association of peptic ulcer with the ratio of cholesterol to total lipids in medium VLDL was observed in the inverse Mendelian randomization analysis. CONCLUSION: In conclusion, our study reveals a significant association between the ratio of cholesterol to total lipids in medium VLDL and an elevated risk of peptic ulcers. However, further validation through laboratory investigations and larger-scale studies is warranted to strengthen the evidence and confirm the causal relationship between these factors.
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Background: Identification of the unknown pathogenic factor driving atherosclerosis not only enhances the development of disease biomarkers but also facilitates the discovery of new therapeutic targets, thus contributing to the improved management of coronary artery disease (CAD). We aimed to identify causative protein biomarkers in CAD etiology based on proteomics and 2-sample Mendelian randomization (MR) design. Methods: Serum samples from 33 first-onset CAD patients and 31 non-CAD controls were collected and detected using protein array. Differentially expressed analyses were used to identify candidate proteins for causal inference. We used 2-sample MR to detect the causal associations between the candidate proteins and CAD. Network MR was performed to explore whether metabolic risk factors for CAD mediated the risk of identified protein. Vascular expression of candidate protein in situ was also detected. Results: Among the differentially expressed proteins identified utilizing proteomics, we found that circulating Golgi protein 73 (GP73) was causally associated with incident CAD and other atherosclerotic events sharing similar etiology. Network MR approach showed low-density lipoprotein cholesterol and glycated hemoglobin serve as mediators in the causal pathway, transmitting 42.1% and 8.7% effects from GP73 to CAD, respectively. Apart from the circulating form of GP73, both mouse model and human specimens imply that vascular GP73 expression was also upregulated in atherosclerotic lesions and concomitant with markers of macrophage and phenotypic switching of vascular smooth muscle cells (VSMCs). Conclusions: Our study supported GP73 as a biomarker and causative for CAD. GP73 may involve in CAD pathogenesis mainly via dyslipidemia and hyperglycemia, which may enrich the etiological information and suggest future research direction on CAD.
Subject(s)
Biomarkers , Coronary Artery Disease , Membrane Proteins , Mendelian Randomization Analysis , Proteomics , Humans , Coronary Artery Disease/blood , Coronary Artery Disease/genetics , Coronary Artery Disease/pathology , Mice , Animals , Membrane Proteins/genetics , Membrane Proteins/blood , Male , Female , Biomarkers/blood , Middle Aged , Cholesterol, LDL/blood , Glycated Hemoglobin/analysis , Glycated Hemoglobin/metabolism , Case-Control Studies , Atherosclerosis/blood , Atherosclerosis/geneticsABSTRACT
The current standard method for amino acid signal identification in protein NMR spectra is sequential assignment using triple-resonance experiments. Good software and elaborate heuristics exist, but the process remains laboriously manual. Machine learning does help, but its training databases need millions of samples that cover all relevant physics and every kind of instrumental artifact. In this communication, we offer a solution to this problem. We propose polyadic decompositions to store millions of simulated three-dimensional NMR spectra, on-the-fly generation of artifacts during training, a probabilistic way to incorporate prior and posterior information, and integration with the industry standard CcpNmr software framework. The resulting neural nets take [1H,13C] slices of mixed pyruvate-labeled HNCA spectra (different CA signal shapes for different residue types) and return an amino acid probability table. In combination with primary sequence information, backbones of common proteins (GB1, MBP, and INMT) are rapidly assigned from just the HNCA spectrum.
Subject(s)
Proteins , Proteins/chemistry , Nuclear Magnetic Resonance, Biomolecular/methods , Software , Amino Acids/chemistry , Algorithms , Isotopes/chemistry , Machine LearningABSTRACT
Diatoms play a crucial role in marine primary productivity through carbon fixation, which is essential for understanding the operation of marine biological pumps and carbon sinks. This study focuses on the phosphoenolpyruvate carboxylase (PEPC) gene, a key enzyme in the carbon assimilation pathway of diatoms, by investigating the consequences of its silencing in Skeletonemacostatum. Through this approach, we aimed to clarify the distinct contributions of PEPC to the overall carbon fixation process. The mutant strains of S. costatum were subjected to thorough analysis to identify any shifts in physiological behavior, alterations in the gene expression of key carbon-fixing enzymes, and changes in the associated enzyme activities. Notably, the inhibition of the PEPC gene did not significantly affect the growth rate of S. costatum; however, it did have a notable impact on the photosynthetic apparatus, as evidenced by a reduction in the maximal electron transport rate and a decline in light utilization efficiency. A significant decrease was observed in both the enzymatic activity and gene expression of PEPCase. This down-regulation also affected other enzymes integral to the carbon fixation pathway, such as phosphoenolpyruvate carboxykinase and pyruvate-phosphate dikinase, indicating a wider metabolic perturbation. In contrast, the expression and activity of the Rubisco enzyme suggested that some facets of carbon fixation remained resilient. Furthermore, the substantial upregulation of carbonic anhydrase expression and activity probably represented an adaptive mechanism to sustain the inorganic carbon supply necessary for the carboxylation process of Rubisco. This research not only underscores the pivotal role of the PEPC gene in the carbon fixation of S. costatum but also expands our comprehension of carbon fixation mechanisms in diatoms.
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BACKGROUND: Post-transplant lymphoproliferative disorders (PTLD) are rare but severe complications that occur after solid organ or allogeneic hematopoietic stem cell transplantations (allo-HSCT), with rapid progression and high mortality. Primary central nervous system (CNS)-PTLD are rarely recognized histo-pathologically. In addition, the diagnostic value of the Epstein-Barr virus (EBV) DNA copies in CNS-PTLD remains poorly understood. OBJECTIVES: We herein report a case of monomorphic EBV-associated CNS-PTLD (diffuse large B-cell lymphoma, DLBCL) after allo-HSCT and perform a meta-analysis to assess the efficacy of PTLD treatment strategies in recent years. METHODS: We present the case report covering clinical manifestations, diagnosis, treatment, and outcomes of a patient with primary CNS-PTLD. Additionally, we include a systematic review and meta-analysis of the clinical characteristics of 431 patients with PTLD after allo-HSCT. We evaluate the main treatment options and outcomes of PTLD management, including rituximab, chemotherapies, and autologous or human leukocyte antigen (HLA)-matched EBV-specific cytotoxic T lymphocyte infusion (EBV-CTLs)/donor lymphocyte infusion (DLI). RESULTS: The meta-analysis revealed an overall response rate of 69.0% for rituximab alone (95% CI: 0.47-0.84), 45.0% for rituximab plus chemotherapies (95% CI: 0.15-0.80), and 91.0% for rituximab plus EBV-CTLs/DLI (95% CI: 0.83-0.96). The complete response (CR) rate after treatments for PTLD was 67.0% (95% CI: 0.56-0.77). Moreover, the 6-month and 1-year overall survival (OS) rate was 64.0% (95% CI: 0.31-0.87) and 49.0% (95% CI: 0.31-0.68), respectively. CONCLUSIONS: This case highlighted the urgent need for effective, low-toxic treatment regimens for CNS-PTLD. Our meta-analysis suggested that rituximab combined with EBV-CTLs/DLI could be a favorable strategy for the management of PTLD after allo-HSCT.
Subject(s)
Epstein-Barr Virus Infections , Hematopoietic Stem Cell Transplantation , Lymphoproliferative Disorders , Humans , Hematopoietic Stem Cell Transplantation/adverse effects , Epstein-Barr Virus Infections/complications , Lymphoproliferative Disorders/etiology , Lymphoproliferative Disorders/diagnosis , Lymphoproliferative Disorders/therapy , Herpesvirus 4, Human/isolation & purification , Herpesvirus 4, Human/genetics , Transplantation, Homologous/adverse effects , Male , Lymphoma, Large B-Cell, Diffuse/virology , Lymphoma, Large B-Cell, Diffuse/therapy , Adult , Female , Rituximab/therapeutic use , Middle AgedABSTRACT
Inpatient falls are common adverse events especially for patients with hematologic malignancies. A fall-risk prediction model for patients with hematologic malignancies are still needed. Here we conducted a multicenter study that prospectively included 516 hospitalized patients with hematologic malignancies, and developed a nomogram for fall risk prediction. Patients were divided into the modeling group (n = 389) and the validation group (n = 127). A questionnaire containing sociodemographic factors, general health factors, disease-related factors, medication factors, and physical activity factors was administered to all patients. Logistic regression analysis revealed that peripheral neuropathy, pain intensity, Morse fall scale score, chemotherapy courses, and myelosuppression days were risk factors for falls in patients with hematologic malignancies. The nomogram model had a sensitivity of 0.790 and specificity of 0.800. The calibration curves demonstrated acceptable agreement between the predicted and observed outcomes. Therefore, the nomogram model has promising accuracy in predicting fall risk in patients with hematologic malignancies.
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Circular RNA (circRNA)-microRNA (miRNA) interaction (CMI) plays crucial roles in cellular regulation, offering promising perspectives for disease diagnosis and therapy. Therefore, it is necessary to employ computational methods for the rapid and cost-effective prediction of potential circRNA-miRNA interactions. However, the existing methods are limited by incomplete data; therefore, it is difficult to model molecules with different attributes on a large scale, which greatly hinders the efficiency and performance of prediction. In this study, we propose an effective method for predicting circRNA-miRNA interactions, called RBNE-CMI, and introduce a framework that can embed incomplete multiattribute CMI heterogeneous networks. By combining the proposed method, we integrate different data sets in the CMI prediction field into one incomplete network for modeling, achieving superior performance in 5-fold cross-validation. Moreover, in the prediction task based on complete data, the proposed method still achieves better performance than the known model. In addition, in the case study, we successfully predicted 18 of the 20 potential cancer biomarkers. The data and source code can be found at https://github.com/1axin/RBNE-CMI.
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BACKGROUND: In June 2019, a patient presented with persistent fever and multiple organ dysfunction after a tick bite at a wetland park in Inner Mongolia. Next-generation sequencing in this patient revealed an infection with a previously unknown orthonairovirus, which we designated Wetland virus (WELV). METHODS: We conducted active hospital-based surveillance to determine the prevalence of WELV infection among febrile patients with a history of tick bites. Epidemiologic investigation was performed. The virus was isolated, and its infectivity and pathogenicity were investigated in animal models. RESULTS: WELV is a member of the orthonairovirus genus in the Nairoviridae family and is most closely related to the tickborne Hazara orthonairovirus genogroup. Acute WELV infection was identified in 17 patients from Inner Mongolia, Heilongjiang, Jilin, and Liaoning, China, by means of reverse-transcriptase-polymerase-chain-reaction assay. These patients presented with nonspecific symptoms, including fever, dizziness, headache, malaise, myalgia, arthritis, and back pain and less frequently with petechiae and localized lymphadenopathy. One patient had neurologic symptoms. Common laboratory findings were leukopenia, thrombocytopenia, and elevated d-dimer and lactate dehydrogenase levels. Serologic assessment of convalescent-stage samples obtained from 8 patients showed WELV-specific antibody titers that were 4 times as high as those in acute-phase samples. WELV RNA was detected in five tick species and in sheep, horses, pigs, and Transbaikal zokors (Myospalax psilurus) sampled in northeastern China. The virus that was isolated from the index patient and ticks showed cytopathic effects in human umbilical-vein endothelial cells. Intraperitoneal injection of the virus resulted in lethal infections in BALB/c, C57BL/6, and Kunming mice. The Haemaphysalis concinna tick is a possible vector that can transovarially transmit WELV. CONCLUSIONS: A newly discovered orthonairovirus was identified and shown to be associated with human febrile illnesses in northeastern China. (Funded by the National Natural Science Foundation of China and the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences.).
Subject(s)
Fever , Humans , Animals , Male , Female , Fever/etiology , Adult , Middle Aged , Mice , China/epidemiology , Tick Bites/complications , Nairovirus/genetics , Nairovirus/isolation & purification , Phylogeny , Aged , Young Adult , Antibodies, Viral/bloodABSTRACT
In the original publication [...].
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The effective method for trypsin purification should be established because trypsin has important economic value. In this work, a novel and simple strategy was proposed for fabricating micron-sized magnetic Fe3O4@agarose-benzamidine beads (MABB) with benzamidine as a ligand, which can efficiently and selectively capture trypsin. The micro-sized MABB, with clear spherical core-shell structure and average particle size of 6.6 µm, showed excellent suspension ability and magnetic responsiveness in aqueous solution. The adsorption capacity and selectivity of MABB towards target trypsin were significantly better than those of non-target lysozyme. According to the Langmuir equation, the maximum adsorption capacity of MABB for trypsin was 1946 mg g-1 at 25 °C, and the adsorption should be a physical sorption process. Furthermore, the initial adsorption rate and half equilibrium time of MABB toward trypsin were 787.4 mg g-1 min-1 and 0.71 min, respectively. To prove the practicability, MABB-based magnetic solid-phase extraction (MSPE) was proposed, and the related parameters were optimized in detail to improve the purification efficiency. With Tris-HCl buffer (50 mM, 10 mM CaCl2, pH 8.0) as extraction buffer, Tris-HCl buffer (50 mM, 100 mM CaCl2, pH 8.0) as rinsing buffer, acidic eluent (0.01 M HCl, 0.5 M NaCl, pH 2.0) as eluent buffer and alkaline buffer (1 M Tris-HCl buffer, pH 10.0) as neutralization solution, the MABB-based MSPE was successfully used for trypsin purification from the viscera of grass carp (Ctenopharyngodon idella). The molecular weight of purified trypsin was determined as approximate 23 kDa through sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The purified trypsin was highly active from 30 °C to 60 °C, with an optimum temperature of 50 °C, and was tolerant to pH variation, exhibiting 85 % of maximum enzyme activity from pH 7.0 to 10.0. The results demonstrated that the proposed MABB-based MSPE could effectively purify trypsin and ensure the biological activity of purified trypsin. Therefore, we believe that the novel MABB could be applicable for efficient purification of trypsin from complex biological systems.
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Cottonseed meal (CSM) and cottonseed protein concentrate (CPC) serve as protein alternatives to fish meal and soybean meal in the feed industry. However, the presence of gossypol residue in CSM and CPC can potentially trigger severe intestinal inflammation, thereby restricting the widespread utilization of these two protein sources. Probiotics are widely used to prevent or alleviate intestinal inflammation, but their efficacy in protecting fish against gossypol-induced enteritis remains uncertain. Here, the protective effect of Pediococcus pentosaceus, a strain isolated from the gut of Nile tilapia (Oreochromis niloticus), was evaluated. Three diets, control diet (CON), gossypol diet (GOS) and GOS supplemented with P. pentosaceus YC diet (GP), were used to feed Nile tilapia for 10 weeks. After the feeding trial, P. pentosaceus YC reduced the activity of myeloperoxidase (MPO) in the proximal intestine (PI) and distal intestine (DI). Following a 7-day exposure to Aeromonas hydrophila, the addition of P. pentosaceus YC was found to increase the survival rate of the fish. P. pentosaceus YC significantly inhibited the oxidative stress caused by gossypol, which was evidenced by lower reactive oxygen species (ROS) and malondialdehyde (MDA), as well as higher activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in PI and DI. Addition of P. pentosaceus YC significantly inhibited enteritis, with the lower expression of pro-inflammatory cytokines (il-1ß, il-6, il-8) and higher expression of anti-inflammatory cytokines tgf-ß. RNA-seq analysis indicated that P. pentosaceus YC supplementation significantly inhibited nlrc3 and promoted nf-κb expression in PI and DI, and the siRNA interference experiment in vivo demonstrated that intestinal inflammation was mediated by NLRC3/NF-κB/IL-1ß signaling pathway. Fecal bacteria transplantation experiment demonstrated that gut microbiota mediated the protective effect of P. pentosaceus YC. These findings offer valuable insights into the application of P. pentosaceus YC for alleviating gossypol-induced intestinal inflammation in fish.
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AIM: To investigate the effects of fibrillin-1 (FBN1) deletion on the integrity of retina-blood barrier function and the apoptosis of vascular endothelial cells under diabetic conditions. METHODS: Streptozotocin (STZ)-induced diabetic mice were used to simulate the diabetic conditions of diabetic retinopathy (DR) patients, and FBN1 expression was detected in retinas from STZ-diabetic mice and controls. In the Gene Expression Omnibus (GEO) database, the GSE60436 dataset was selected to analyze FBN1 expressions in fibrovascular membranes from DR patients. Using lentivirus to knock down FBN1 levels, vascular leakage and endothelial barrier integrity were detected by Evans blue vascular permeability assay, fluorescein fundus angiography (FFA) and immunofluorescence labeled with tight junction marker in vivo. High glucose-induced monkey retinal vascular endothelial cells (RF/6A) were used to investigate effects of FBN1 on the cells in vitro. The vascular endothelial barrier integrity and apoptosis were detected by trans-endothelial electrical resistance (TEER) assay and flow cytometry, respectively. RESULTS: FBN1 mRNA expression was increased in retinas of STZ-induced diabetic mice and fibrovascular membranes of DR patients (GSE60436 datasets) using RNA-seq approach. Besides, knocking down of FBN1 by lentivirus intravitreal injection significantly inhibited the vascular leakage compared to STZ-DR group by Evans blue vascular permeability assay and FFA detection. Expressions of tight junction markers in STZ-DR mouse retinas were lower than those in the control group, and knocking down of FBN1 increased the tight junction levels. In vitro, 30 mmol/L glucose could significantly inhibit viability of RF/6A cells, and FBN1 mRNA expression was increased under 30 mmol/L glucose stimulation. Down-regulation of FBN1 reduced high glucose (HG)-stimulated retinal microvascular endothelial cell permeability, increased TEER, and inhibited RF/6A cell apoptosis in vitro. CONCLUSION: The expression level of FBN1 increases in retinas and vascular endothelial cells under diabetic conditions. Down-regulation of FBN1 protects the retina of early diabetic rats from retina-blood barrier damage, reduce vascular leakage, cell apoptosis, and maintain vascular endothelial cell barrier function.
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BACKGROUND: Faecal haemoglobin (f-Hb) testing is used in colorectal cancer (CRC) screening and increasingly to guide the investigation in patients with symptoms suggestive of CRC. Studies have demonstrated increased mortality with raised f-Hb. AIMS: To assess the association of raised f-Hb with all-cause, non-CRC (any cause excluding CRC) and cause-specific mortality. METHODS: We searched Medline and Embase on 9 February 2024 to identify papers reporting mortality after faecal immunochemical (FIT) or guaiac faecal occult blood tests (gFOBT). The primary outcome was all-cause mortality following a positive compared to a negative test. RESULTS: The search identified 3155 papers. Ten met the inclusion criteria: three reported gFOBT and seven reported FIT results, as screening tests. These reported a total of 14,687,625 f-Hb results. Elevated f-Hb was associated with an increased risk of all-cause, non-CRC and cause-specific mortality including death from cardiovascular, digestive and respiratory diseases. Crude risk ratios for all-cause mortality with a positive versus negative test were derived from six papers (three reporting gFOBT, three FIT). An increased risk was demonstrated in five, with RRs ranging from 1.11 (95% CI: 1.06-1.16) to 2.95 (95% CI: 2.85-3.05). For non-CRC mortality risk, RRs ranged from 1.09 (95% CI: 1.04-1.15) to 2.79 (95% CI: 2.70-2.89). We did not perform meta-analysis due to a limited number of papers reporting suitable results for each type of f-Hb test. CONCLUSIONS: All-cause, non-CRC and cause-specific mortality appear higher in those with raised f-Hb. Population-based studies are warranted to elicit whether this association occurs in symptomatic patients.
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The application of plant sterols in the treatment of hypercholesterolemia is promising. We hypothesize that plant sterols can reduce blood cholesterol because they have a side chain of at least three branches. Three cholesterol analogues were synthesized: CA0 (no side chain), CA3 (a 3carbon chain with one branch), and CA14 (a 14carbon side chain with two branches), and then compared their effect on blood cholesterol with that of ß-sitosterol. Structurally, ß-sitosterol has a 10carbon side chain with three branches. Results demonstrated that ß-sitosterol could effectively reduce plasma total cholesterol (TC) by 20.3%, whereas CA0, CA3 and CA14 did not affect plasma TC in hypercholesterolemia hamsters. ß-Sitosterol was absent in the plasma and liver, indicating it was not absorbed. We concluded that ß-sitosterol with three branches had plasma TC-lowering activity. In contrast, cholesterol analogues with a side chain of two or fewer branches did not affect plasma cholesterol.
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Semiconductive coordination polymers (CPs) have recently garnered a significant amount of attention due to their widespread application in many areas. The "through-space" approach has emerged as the most versatile strategy for constructing semiconductive CPs. However, this approach often leads to the formation of unidirectional charge transport paths, resulting in anisotropic electrically conductive performance and low average conductivities in pressed pellets, thus presenting significant challenges for the practical application of semiconductive CPs. Consequently, there is a strong desire to explore simpler and more versatile strategies for designing semiconductive CPs with dual or multiple charge transport paths. Herein, we report on two semiconductive potassium hydroxamate coordination polymers, denoted as [K(HONDI)(H2O)2]n (1) and [K(HONDI)]n (2). Both compounds theoretically possess dual charge transport paths, occurring internally and externally within the π-π stacking columns of the ligands. Conductivity measurements revealed that compounds 1 and 2 both exhibit semiconductive properties, with their electrical conductivities reaching 2.3 × 10-6 and 1.9 × 10-7 S/cm, respectively, at 30 °C. Their electrically conductive performance could be attributed to theoretically biaxial "band-like" charge transport inside crystals and "hopping" charge transport between grain boundaries.
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BACKGROUND: Rhododendron nivale subsp. boreale Philipson et M. N. Philipson is an alpine woody species with ornamental qualities that serve as the predominant species in mountainous scrub habitats found at an altitude of â¼4,200 m. As a high-altitude woody polyploid, this species may serve as a model to understand how plants adapt to alpine environments. Despite its ecological significance, the lack of genomic resources has hindered a comprehensive understanding of its evolutionary and adaptive characteristics in high-altitude mountainous environments. FINDINGS: We sequenced and assembled the genome of R. nivale subsp. boreale, an assembly of the first subgenus Rhododendron and the first high-altitude woody flowering tetraploid, contributing an important genomic resource for alpine woody flora. The assembly included 52 pseudochromosomes (scaffold N50 = 42.93 Mb; BUSCO = 98.8%; QV = 45.51; S-AQI = 98.69), which belonged to 4 haplotypes, harboring 127,810 predicted protein-coding genes. Conjoint k-mer analysis, collinearity assessment, and phylogenetic investigation corroborated autotetraploid identity. Comparative genomic analysis revealed that R. nivale subsp. boreale originated as a neopolyploid of R. nivale and underwent 2 rounds of ancient polyploidy events. Transcriptional expression analysis showed that differences in expression between alleles were common and randomly distributed in the genome. We identified extended gene families and signatures of positive selection that are involved not only in adaptation to the mountaintop ecosystem (response to stress and developmental regulation) but also in autotetraploid reproduction (meiotic stabilization). Additionally, the expression levels of the (group VII ethylene response factor transcription factors) ERF VIIs were significantly higher than the mean global gene expression. We suspect that these changes have enabled the success of this species at high altitudes. CONCLUSIONS: We assembled the first high-altitude autopolyploid genome and achieved chromosome-level assembly within the subgenus Rhododendron. In addition, a high-altitude adaptation strategy of R. nivale subsp. boreale was reasonably speculated. This study provides valuable data for the exploration of alpine mountaintop adaptations and the correlation between extreme environments and species polyploidization.
Subject(s)
Altitude , Genome, Plant , Haplotypes , Phylogeny , Rhododendron , Tetraploidy , Rhododendron/genetics , Adaptation, Physiological/genetics , Molecular Sequence Annotation , Polyploidy , Gene Expression Regulation, PlantABSTRACT
Shrews being insectivores, serve as natural reservoirs for a wide array of zoonotic viruses, including the recently discovered Langya henipavirus (LayV) in China in 2018. It is crucial to understand the shrew-associated virome, viral diversity, and new viruses. In the current study, we conducted high-throughput sequencing on lung samples obtained from 398 shrews captured along the eastern coast of China, and characterized the high-depth virome of 6 common shrew species (Anourosorex squamipes, Crocidura lasiura, Crocidura shantungensis, Crocidura tanakae, Sorex caecutiens, and Suncus murinus). Our analysis revealed numerous shrew-associated viruses comprising 54 known viruses and 72 new viruses that significantly enhance our understanding of mammalian viruses. Notably, 34 identified viruses possess spillover-risk potential and six were human pathogenic viruses: LayV, influenza A virus (H5N6), rotavirus A, rabies virus, avian paramyxovirus 1, and rat hepatitis E virus. Moreover, ten previously unreported viruses in China were discovered, six among them have spillover-risk potential. Additionally, all 54 known viruses and 12 new viruses had the ability to cross species boundaries. Our data underscore the diversity of shrew-associated viruses and provide a foundation for further studies into tracing and predicting emerging infectious diseases originated from shrews.
Subject(s)
High-Throughput Nucleotide Sequencing , Lung , Shrews , Virome , Animals , Shrews/virology , China , Lung/virology , Virome/genetics , Phylogeny , RNA Viruses/genetics , RNA Viruses/classification , RNA Viruses/isolation & purification , RNA, Viral/genetics , Influenza A virus/genetics , Influenza A virus/classification , Influenza A virus/isolation & purification , Rabies virus/genetics , Rabies virus/classification , Rabies virus/isolation & purification , Disease Reservoirs/virologyABSTRACT
ß-Branched chiral amines with contiguous stereocenters are valuable building blocks for preparing various biologically active molecules. However, their asymmetric synthesis remains challenging. Herein, we report a highly diastereo- and enantioselective biocatalytic approach for preparing a broad range of ß-branched chiral amines starting from their corresponding racemic ketones. This involves a dynamic kinetic resolution-asymmetric reductive amination process catalyzed using only an imine reductase. Four rounds of protein engineering endowed wild-type PocIRED with higher reactivity, better stereoselectivity, and a broader substrate scope. Using the engineered enzyme, various chiral amine products were synthesized with up to >99.9% ee, >99:1 dr, and >99% conversion. The practicability of the developed biocatalytic method was confirmed by producing a key intermediate of tofacitinib in 74% yield, >99.9% ee, and 98:2 dr at a challenging substrate loading of 110 g L-1. Our study provides a highly capable imine reductase and a protocol for developing an efficient biocatalytic dynamic kinetic resolution-asymmetric reductive amination reaction system.
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The oxygen evolution reaction (OER) performance of ruthenium-based oxides strongly correlates with the electronic structures of Ru. However, the widely adopted monometal doping method unidirectionally regulates only the electronic structures, often failing to balance the activity and stability. Here, we propose an "elastic electron transfer" strategy to achieve bidirectional optimization of the electronic structures of Sr, Cr codoped RuO2 catalysts for acidic OER. The introduction of electron-withdrawing Sr intrinsically activates the Ru sites by increasing the oxidation state of Ru. Simultaneously, Cr acts as an electron buffer, donating electrons to Ru in the presence of Sr in the as-prepared catalysts and absorbing excess electrons from Sr leaching during the OER. Such a bidirectional regulation feature of Cr prevents overoxidation of Ru and maintains its high oxidation state during the OER. The optimal Ru3Cr1Sr0.175 catalyst exhibits a low overpotential (214 mV @ 10 mA cm-2) and excellent stability (over 300 h).