Structural basis of bifunctional CTP/dCTP synthase.

The final step in the de novo synthesis of cytidine 5'-triphosphate (CTP) is catalyzed by CTP synthase (CTPS), which can form cytoophidia in all three domains of life. Recently, we have discovered that CTPS binds to ribonucleotides (NTPs) to form filaments, and have successfully solved the structures of Drosophila melanogaster CTPS bound with NTPs. Previous biochemical studies have shown that CTPS can bind to deoxyribonucleotides (dNTPs) to produce 2'-deoxycytidine-5'-triphosphate (dCTP). However, the structural basis of CTPS binding to dNTPs is still unclear. In this study, we find that Drosophila CTPS can also form filaments with dNTPs. Using cryo-electron microscopy, we are able to solve the structure of Drosophila melanogaster CTPS bound to dNTPs with a resolution of up to 2.7 Å. By combining these structural findings with biochemical analysis, we compare the binding and reaction characteristics of NTPs and dNTPs with CTPS. Our results indicate that the same enzyme can act bifunctionally as CTP/dCTP synthase in vitro, and provide a structural basis for these activities.

Synthesis of Benzopyrone-Fused Hydrobenzo[c,d]indoles via Cascade Annulation of p-Quinamines and 3-Formylchromones.

A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed cascade annulation reaction between p-quinamines and 3-formylchromones was developed, affording a series of benzopyrone-fused hydrobenzo[c,d]indoles in moderate to high yields with excellent diastereoselectivity. This cascade reaction is efficient since two new rings as well as one C-N, one C═C, and two C-C bonds are created in a single step. The scale-up synthesis and versatile transformations of the products further demonstrated the practicality and utility of this approach.

Isolation and Characterization of Meniscus Progenitor Cells From Rat, Rabbit, Goat, and Human.

OBJECTIVE: Meniscus progenitor cells (MPCs) have been identified as promising candidates for meniscus regeneration, and it is crucial for us to understand meniscus injury repair mechanism at the cellular level. In this study, we investigate the biological properties of MPCs isolated from different species using the differential adhesion to fibronectin (DAF) technique. We aim to characterize MPCs in different species and evaluate the feasibility of these models for future meniscal investigation. DESIGN: MPCs were isolated from freshly digested meniscus from rat, rabbit, goat, and human cells using DAF. Biological properties, including proliferation, colony-forming, multilineage differentiation, and migration abilities, were compared in MPCs and their corresponding mixed meniscus cell (MCs) population in each species. RESULTS: MPCs were successfully isolated by the DAF technique in all species. Rat MPCs appeared cobblestone-like, rabbit MPCs were more polygonal, goat MPCs had a spindle-shaped morphology, human MPCs appear more fibroblast-like. Compared with MCs, isolated MPCs showed progenitor cell characteristics, including multilineage differentiation ability and MSC (mesenchymal stem cells) markers (CD166, CD90, CD44, Stro-1) expression. They also highly expressed fibronectin receptors CD49e and CD49c. MPCs also showed greater proliferation capacity and retained colony-forming ability. Except for goat MPCs showed greater migration abilities than MCs, no significant differences were found in the migration ability between MPCs and MCs in other species. CONCLUSION: Our study shows that DAF is an effective method for isolating MPCs from rat, rabbit, goat, and human. MPCs in these species demonstrated similar characteristics, including greater proliferation ability and better chondrogenic potential.

Uveal melanoma distant metastasis prediction system: A retrospective observational study based on machine learning.

Uveal melanoma (UM) patients face a significant risk of distant metastasis, closely tied to a poor prognosis. Despite this, there is a dearth of research utilizing big data to predict UM distant metastasis. This study leveraged machine learning methods on the Surveillance, Epidemiology, and End Results (SEER) database to forecast the risk probability of distant metastasis. Therefore, the information on UM patients from the SEER database (2000-2020) was split into a 7:3 ratio training set and an internal test set based on distant metastasis presence. Univariate and multivariate logistic regression analyses assessed distant metastasis risk factors. Six machine learning methods constructed a predictive model post-feature variable selection. The model evaluation identified the multilayer perceptron (MLP) as optimal. Shapley additive explanations (SHAP) interpreted the chosen model. A web-based calculator personalized risk probabilities for UM patients. The results show that nine feature variables contributed to the machine learning model. The MLP model demonstrated superior predictive accuracy (Precision = 0.788; ROC AUC = 0.876; PR AUC = 0.788). Grade recode, age, primary site, time from diagnosis to treatment initiation, and total number of malignant tumors were identified as distant metastasis risk factors. Diagnostic method, laterality, rural-urban continuum code, and radiation recode emerged as protective factors. The developed web calculator utilizes the MLP model for personalized risk assessments. In conclusion, the MLP machine learning model emerges as the optimal tool for predicting distant metastasis in UM patients. This model facilitates personalized risk assessments, empowering early and tailored treatment strategies.

Synthesis, Structure, and Magnetic Properties of Cyanurates RE5(C3N3O3)(OH)12 (RE = Gd-Lu): Cryogenic Magnetocaloric Candidate Gd5(C3N3O3)(OH)12.

Rare-earth (RE)-based frustrated magnets are fertile playgrounds for discovering exotic quantum phenomena and exploring adiabatic demagnetization refrigeration applications. Here, we report the synthesis, structure, and magnetic properties of a family of rare-earth cyanurates RE5(C3N3O3)(OH)12 (RE = Gd-Lu) with an acentric space group P6̅2m. Magnetic susceptibility χ(T) and isothermal magnetization M(H) measurements manifest that RE5(C3N3O3)(OH)12 (RE = Gd, Dy-Yb) compounds exhibit no magnetic ordering down to 2 K, while Tb5(C3N3O3)(OH)12 shows long-range magnetic ordering around 3.6 K. Among them, magnetically frustrated spin-7/2 Gd5(C3N3O3)(OH)12 shows long-range magnetic ordering around 1.25 K and a large magnetocaloric effect with a maximum magnetic entropy change ΔSm of up to 58.1 J kg-1 K-1 at ΔH = 7 T at liquid-helium temperature regimes.

Advances in electroactive biomaterials: Through the lens of electrical stimulation promoting bone regeneration strategy.

The regenerative capacity of bone is indispensable for growth, given that accidental injury is almost inevitable. Bone regenerative capacity is relevant for the aging population globally and for the repair of large bone defects after osteotomy (e.g., following removal of malignant bone tumours). Among the many therapeutic modalities proposed to bone regeneration, electrical stimulation has attracted significant attention owing to its economic convenience and exceptional curative effects, and various electroactive biomaterials have emerged. This review summarizes the current knowledge and progress regarding electrical stimulation strategies for improving bone repair. Such strategies range from traditional methods of delivering electrical stimulation via electroconductive materials using external power sources to self-powered biomaterials, such as piezoelectric materials and nanogenerators. Electrical stimulation and osteogenesis are related via bone piezoelectricity. This review examines cell behaviour and the potential mechanisms of electrostimulation via electroactive biomaterials in bone healing, aiming to provide new insights regarding the mechanisms of bone regeneration using electroactive biomaterials. The translational potential of this article: This review examines the roles of electroactive biomaterials in rehabilitating the electrical microenvironment to facilitate bone regeneration, addressing current progress in electrical biomaterials and the mechanisms whereby electrical cues mediate bone regeneration. Interactions between osteogenesis-related cells and electroactive biomaterials are summarized, leading to proposals regarding the use of electrical stimulation-based therapies to accelerate bone healing.

Stabilization of Short- and Long-Range Magnetic Ordering through the Cooperative Effect of 1D [CuO4] Chains and [CuO2X2] Quadrilateral in Quasi-1D Spin-1/2 Systems.

Quasi-1D chain antiferromagnets with reduced structural dimensionality are a rich playground for investigating novel quantum phenomena. We report the synthesis, crystal structure, and magnetism of two novel quasi-1D antiferromagnets,  ß-PbCu2(TeO3)2Cl2 (I) and PbCu2(TeO3)2Br2 (II). Their magnetic frameworks are constructed via Cu-based quasi-1D [Cu(2)O4] zigzag chains with square-planar [Cu(1)O2X2] (X = Cl or Br) separated among 1D chains. Specific heat measurements show l peaks at ~9 K and ~19 K for  I and II, respectively. Moreover, both broad maximums (χmax = 90 K for I and 80 K for II) and small kinks (TN ≈ 9 K for I and 19 K for II) have been observed in magnetic susceptibility measurements of I and II. Bonner-Fisher model fitting, and theoretical analyses were performed to evaluate the magnetic exchange interactions. Our experimental and theoretical results and structure-properties relationship analysis reveal the coexistence of short- and long-range magnetic ordering from the cooperative effect of 1D [CuO4] chains and [CuO2X2] quadrilateral.

Long-term associations of PM1 versus PM2.5 and PM10 with asthma and asthma-related respiratory symptoms in the middle-aged and elderly population.

Background: Few studies have compared the associations between long-term exposures to particulate matters (aerodynamic diameter ≤1, ≤2.5 and ≤10 µm: PM1, PM2.5 and PM10, respectively) and asthma and asthma-related respiratory symptoms. The objective of the present study was to compare the strength of the aforementioned associations in middle-aged and elderly adults. Methods: We calculated the mean 722-day personal exposure estimates of PM1, PM2.5 and PM10 at 1 km×1 km spatial resolution between 2013 and 2019 at individual levels from China High Air Pollutants (CHAP) datasets. Using logistic regression models, we presented the associations as odds ratios and 95% confidence intervals, for each interquartile range (IQR) increase in PM1/PM2.5/PM10 concentration. Asthma denoted a self-reported history of physician-diagnosed asthma or wheezing in the preceding 12 months. Results: We included 7371 participants in COPD surveillance from Guangdong, China. Each IQR increase in PM1, PM2.5 and PM10 was associated with a greater odds (OR (95% CI)) of asthma (PM1: 1.22 (1.02-1.45); PM2.5: 1.24 (1.04-1.48); PM10: 1.30 (1.07-1.57)), wheeze (PM1: 1.27 (1.11-1.44); PM2.5: 1.30 (1.14-1.48); PM10: 1.34 (1.17-1.55)), persistent cough (PM1: 1.33 (1.06-1.66); PM2.5: 1.36 (1.09-1.71); PM10: 1.31 (1.02-1.68)) and dyspnoea (PM1: 2.10 (1.84-2.41); PM2.5: 2.17 (1.90-2.48); PM10: 2.29 (1.96-2.66)). Sensitivity analysis results were robust after excluding individuals with a family history of allergy. Associations of PM1, PM2.5 and PM10 with asthma and asthma-related respiratory symptoms were slightly stronger in males. Conclusion: Long-term exposure to PM is associated with increased risks of asthma and asthma-related respiratory symptoms.

Effects of comprehensive nursing intervention on quality of life, Self-efficacy, gastrointestinal reaction and immune function of patients with breast cancer undergoing chemotherapy.

Objective: To assess the effects of comprehensive nursing intervention on quality of life, self-efficacy, gastrointestinal reaction and immune function of patients with breast cancer undergoing chemotherapy. Methods: This was a retrospective study. One hundred and twenty patients receiving chemotherapy after breast cancer surgery were randomly divided into the experimental group and the control group(n=60) from January 2021 to January 2023. Patients in the perioperative period, the experimental group were given comprehensive nursing intervention, while those in the control group were given conventional specialist nursing intervention. The differences in quality of life, self-efficacy, gastrointestinal reaction, immune function and patient satisfaction between the two groups were compared and analyzed. Results: After the intervention, the SF-36 scores in the experimental group were significantly higher than those in the control group (P=0.00), the efficacy indicators were significantly improved compared to the control group(P=0.00); the scores of gastrointestinal symptoms in the experimental group were significantly lower than those in the control group after the intervention(P<0.05). The indexes of CD3+, CD4+ and CD4+/CD8+ in the experimental group after the intervention were significantly higher than those in the control group(P=0.00); The patient satisfaction in the experimental group was 100%, which was significantly higher than 92% in the control group, with statistically significant differences(P=0.02). Conclusion: Comprehensive nursing intervention leads to a variety of benefits in the treatment of patients with breast cancer during postoperative chemotherapy, such as relieving patients' gastrointestinal reactions, improving their immune function and quality of life, besides effectively improving their self-efficacy, which is worthy of clinical application.

[Effect of Partial Substitution of Chemical Fertilizers with Organic Fertilizers on N2O and NO Emissions from a Peach Orchard].

Organic fertilizer substitution has been promoted as a weight loss, efficient, and diversified fertilizer substitution technology in agricultural production. However, there is a lack of comprehensive assessment of the impact of organic fertilizers on N2O and NO emissions from orchards. In this study, N2O and NO emissions from peach orchards were observed annually using static dark box-gas chromatography to compare the effects of chemical fertilizer application alone and partial replacement of chemical fertilizer treatment on NO emissions from peach orchards. The results showed that the partial replacement of chemical fertilizers with organic fertilizers reduced the total N2O and NO emissions from peach orchards by 15.0 % and 9.4 %, respectively. The N2O and NO emission factors were reduced by 21.3 % and 21.1 %. The mineral N content of the soil in the organic fertilizer treatment was lower than that in the chemical fertilizer treatment alone. The organic fertilizer treatment increased the contribution of AOA to nitrification and decreased the contribution of AOB, thus reducing N2O and NO from nitrification. In addition, the results of the dual isotope mixing model[δ18O(N2O/H2O) vs. δ15NSP] indicated that the bacterial denitrification/nitrifying bacterial denitrification (bD/nD) process served as the primary pathway for N2O emissions in peach orchards. Partial substitution with organic fertilizers enhanced soil denitrification, resulting in larger reductions in the amounts of N2O and NO. Therefore, partial substitution of organic fertilizer is a viable measure to mitigate nitrogen oxide emissions from orchards and to achieve green and low-carbon development in agriculture.

Psychometric and structural properties of the traditional Chinese version of the sleep condition indicator for patients undergoing hemodialysis.

PURPOSE: Insomnia is a prevalent sleep disorder among patients undergoing hemodialysis for chronic kidney disease. This study aimed to translate the sleep condition indicator (SCI), an insomnia screening tool based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), into a traditional Chinese version (SCI-TC) and evaluate the reliability and validity of this version for patients undergoing hemodialysis. METHODS: This cross-sectional study conducted from November 2022 to June 2023 involved 200 patients on hemodialysis (mean age, 65.56 years; 61.5% men). Participants completed a series of questionnaires, with insomnia diagnosed according to DSM-5 criteria as the gold standard. A receiver operating characteristic (ROC) curve analysis was conducted to examine the sensitivity and specificity of the SCI-TC. RESULTS: According to the DSM-5 criteria, 38% of the participants had insomnia. Cronbach's alpha for the SCI-TC was 0.92. The SCI-TC exhibited a good fit as a two-factor model, and its scores were significantly associated with those of the traditional Chinese versions of the Insomnia Severity Index, Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, EuroQol 5-Dimensions scale, and EuroQol Visual Analogue Scale (r = - 0.94, - 0.53, - 0.38, 0.27, and 0.30, respectively; all p < 0.05). The ROC curve analysis revealed an optimal cutoff of 16 points, with the sensitivity, specificity, and area under curve of 88.2%, 84.7%, and 0.91(95% confidence interval, 0.87-0.95), respectively. CONCLUSION: The SCI-TC demonstrates robust reliability and validity in detecting insomnia among patients undergoing hemodialysis. These findings suggest that health-care providers should considering using the SCI as an easy-to-use tool for the timely detection of insomnia in this population.

[Clinical Observation on Haploid Hematopoietic Stem Cells Combined with Umbilical Cord Blood Double Transplantation for Aplastic Anaemia in Children].

OBJECTIVE: To explore the efficacy and safety of haploidentical hematopoietic stem cell transplantation combined with umbilical cord blood infusion for the treatment of aplastic anaemia in children. METHODS: Nine cases of children with aplastic anaemia treated with umbilical cord blood combined with haploidentical hematopoietic stem cell transplantation at the People's Hospital of Henan University of Chinese Medicine from January 1, 2021 to September 15, 2023 with a median age of 11(2-13) years and a median follow up of 18(7.5-21) months were included, and the clinical data were retrospectively analyzed. Hematopoiesis reconstitution, the incidence of graft-versus-host disease(GVHD), infections and survival of the patients were analyzed. RESULTS: All 9 children were successfully implanted. The median time to neutrophil and platelet implantation was 11.11±1.27 d and 12.44±3.36 d, respectively. One case developed acute gastrointestinal GVHD of degree I, which was improved after treatment, and the patient developed superficial gastritis and chronic gastrointestinal GVHD at a later stage, which is currently under clinical follow-up. Acute GVHD of II-IV degree was 0%. Hemorrhagic cystitis in 3 cases, CMV infection in 5 cases and bacterial and fungal infections in 5 cases improved with symptomatic treatment.All 9 children demonstrated complete donor chimerism within 1 month after transplantation, at two years of follow-up, all nine children survived without recurrence or development of grade II-IV GVHD, and there were no children with transplant-related deaths. CONCLUSION: Haploidentical hematopoietic stem cell transplantation combined with umbilical cord blood transfusion for aplastic anaemia in children has a low incidence and mild degree of GVHD, with significant efficacy, and can be used as a therapeutic option for children without an HLA full donor chimeric match.

Introduction of the difluoromethyl group at the meta- or para-position of pyridines through regioselectivity switch.

Difluoromethyl pyridines have gained significant attention in medicinal and agricultural chemistry. The direct C-H-difluoromethylation of pyridines represents a highly efficient economic way to access these azines. However, the direct meta-difluoromethylation of pyridines has remained elusive and methods for site-switchable regioselective meta- and para-difluoromethylation are unknown. Here, we demonstrate the meta-C-H-difluoromethylation of pyridines through a radical process by using oxazino pyridine intermediates, which are easily accessed from pyridines. The selectivity can be readily switched to para by in situ transformation of the oxazino pyridines to pyridinium salts upon acid treatment. The preparation of various meta- and para-difluoromethylated pyridines through this approach is presented. The mild conditions used also allow for the late-stage meta- or para-difluoromethylation of pyridine containing drugs. Sequential double functionalization of pyridines is presented, which further underlines the value of this work.

Novel CCR3-targeted cyclic peptides as potential therapeutic agents for age-related macular degeneration via inhibiting angiogenesis and reducing retinal photoreceptor damage.

The prolonged intravitreal administration of anti-vascular endothelial growth factor (VEGF) drugs is prone to inducing aberrant retinal vascular development and causing damage to retinal neurons. Hence, we have taken an alternative approach by designing and synthesizing a series of cyclic peptides targeting CC motif chemokine receptor 3 (CCR3). Based on the binding mode of the N-terminal region in CCR3 protein to CCL11, we used computer-aided identification of key amino acid sequence, conformational restriction through different cyclization methods, designed and synthesized a series of target cyclic peptides, and screened the preferred compound IB-2 through affinity. IB-2 exhibits excellent anti-angiogenic activity in HRECs. The apoptosis level of 661W cells demonstrated a significant decrease with the escalating concentration of IB-2. This suggests that IB-2 may have a protective effect on photoreceptor cells. In vivo experiments have shown that IB-2 significantly reduces retinal vascular leakage and choroidal neovascularization (CNV) area in a laser-induced mouse model of CNV. These findings indicate the potential of IB-2 as a safe and effective therapeutic agent for AMD, warranting further development.

Effectiveness of Acupressure for Fatigue Alleviation in Patients Receiving Hemodialysis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Fatigue, a major health concern among patients receiving hemodialysis, is associated with poor quality of life, negative emotions, and cognitive dysfunction. Acupressure is a low-cost and noninvasive traditional Chinese therapy that has been widely used in community and clinic settings. However, the beneficial effects of acupressure on various aspects of fatigue among these patients have not been systematically investigated. PURPOSE: This study was designed to determine the effects of acupressure on fatigue in patients receiving hemodialysis. The moderating influences of bio-sociodemographic characteristics and methodology on the association between acupressure and posthemodialysis fatigue were also examined. METHODS: Four electronic databases were searched for qualified articles published between database inception and November 2, 2022. Only randomized controlled trials designed to investigate the effects of acupressure on fatigue in patients receiving hemodialysis were qualified for consideration. A random-effects model was used for data analysis. RESULTS: Eight randomized controlled trials with 11 effect sizes and 725 participants were included in this study. In these studies, acupressure was found to have a significantly higher alleviation effect on general fatigue (g = -0.78; 95% confidence interval [-1.09, -0.48]) and the behavioral, emotional, sensory, and cognitive domains of fatigue (g = -0.51, -0.51, -0.72, and -0.41, respectively) among patients receiving hemodialysis than those in the control groups. Furthermore, the stimulation of the Shenmen acupoint was found to increase the effects (p < .01) of acupressure on fatigue reduction significantly. Notably, the use of special equipment to perform the acupressure was not found to significantly improve outcomes (p = .99). CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Acupressure is effective in alleviating fatigue in patients receiving hemodialysis, particularly when the Shenmen acupoint is used together with other acupoints, and is effective without the application of special equipment. Acupressure may be adopted as a complementary therapy for fatigue alleviation in patients receiving hemodialysis. Based on the findings, healthcare providers should coach patients receiving hemodialysis with fatigue on how to use acupressure therapy appropriately to alleviate this health concern.

Application and Perspectives: Magnesium Materials in Bone Regeneration.

The field of bone regeneration has always been a hot and difficult research area, and there is no perfect strategy at present. As a new type of biodegradable material, magnesium alloys have excellent mechanical properties and bone promoting ability. Compared with other inert metals, magnesium alloys have significant advantages and broad application prospects in the field of bone regeneration. By searching the official Web sites and databases of various funds, this paper summarizes the research status of magnesium composites in the field of bone regeneration and introduces the latest scientific research achievements and clinical transformations of scholars in various countries and regions, such as improving the corrosion resistance of magnesium alloys by adding coatings. Finally, this paper points out the current problems and challenges, aiming to provide ideas and help for the development of new strategies for the treatment of bone defects and fractures.

[Role of NLRP3 inflammasome in heart failure and traditional Chinese medicine intervention: a review].

Heart failure is characterized by high incidence and mortality rates, and the search for effective treatment strategies for heart failure and the improvement of clinical outcomes have always been important research directions. Imbalanced inflammation has been proven to be one of the critical pathological factors in heart failure, positively correlated with adverse events such as impaired cardiac function and myocardial fibrosis. In recent years, studies have confirmed that the activation of the NOD-like receptor thermal protein domain-associated protein 3(NLRP3) inflammasome plays a common regulatory role in the inflammation imbalance induced by various factors in heart failure. Moreover, certain traditional Chinese medicine(TCM) and active components can significantly inhibit the activation of the NLRP3 inflammasome, thereby improving heart failure. This article first overviewed the basic information about the NLRP3 inflammasome, summarized the regulatory mechanisms of the NLRP3 inflammasome in heart failure induced by various factors, introduced recent research progress on TCM and active components that inhibited the NLRP3 inflammasome to improve heart failure, aiming to provide references for innovative drug research in the field of integrated Chinese and western medicine for the prevention and treatment of heart failure.

Meta-Selective Copper-Catalyzed C-H Arylation of Pyridines and Isoquinolines through Dearomatized Intermediates.

C(sp2)-H functionalization offers an efficient strategy for the synthesis of various elaborated N-containing heteroarenes. Along these lines, oxazino pyridines that can be readily prepared from pyridines, have been introduced as powerful substrates in radical- and ionic-mediated meta-C-H functionalization. However, the regioselective meta-C-H arylation of pyridines remains a great challenge. Herein, a copper-catalyzed meta-selective C-H arylation of pyridines and isoquinolines through bench-stable dearomatized intermediates is reported. Electrophilic aryl-Cu(III) species, generated from readily accessible aryl I(III) reagents, enable the efficient meta-arylation of a broad range of pyridines and isoquinolines. The method also allows the meta-selective alkenylation of these heteroarenes using the corresponding alkenyl I(III)-reagents. Late-stage arylation of drug-derived pyridines and larger-scale experiments demonstrate the potential of this synthetic methodology.