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1.
Mol Cell ; 82(21): 4160-4175.e6, 2022 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-36272409

RESUMO

CRISPR-Cas9-mediated genome editing depends on PAM recognition to initiate DNA unwinding. PAM mutations can abolish Cas9 binding and prohibit editing. Here, we identified a Cas9 from the thermophile Alicyclobacillus tengchongensis for which the PAM interaction can be robustly regulated by DNA topology. AtCas9 has a relaxed PAM of N4CNNN and N4RNNA (R = A/G) and is able to bind but not cleave targets with mutated PAMs. When PAM-mutated DNA was in underwound topology, AtCas9 exhibited enhanced binding affinity and high cleavage activity. Mechanistically, AtCas9 has a unique loop motif, which docked into the DNA major groove, and this interaction can be regulated by DNA topology. More importantly, AtCas9 showed near-PAMless editing of supercoiled plasmid in E. coli. In mammalian cells, AtCas9 exhibited broad PAM preference to edit plasmid with up to 72% efficiency and effective base editing at four endogenous loci, representing a potentially powerful tool for near-PAMless editing.


Assuntos
Sistemas CRISPR-Cas , Escherichia coli , Animais , Escherichia coli/genética , Escherichia coli/metabolismo , Edição de Genes , DNA/genética , Plasmídeos , Mamíferos/metabolismo
2.
Plant Physiol ; 195(1): 617-639, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38285060

RESUMO

Revealing the genetic basis for stress-resistant traits in extremophile plants will yield important information for crop improvement. Zygophyllum xanthoxylum, an extant species of the ancient Mediterranean, is a succulent xerophyte that can maintain a favorable water status under desert habitats; however, the genetic basis of this adaptive trait is poorly understood. Furthermore, the phylogenetic position of Zygophyllales, to which Z. xanthoxylum belongs, remains controversial. In this study, we sequenced and assembled the chromosome-level genome of Z. xanthoxylum. Phylogenetic analysis showed that Zygophyllales and Myrtales form a separated taxon as a sister to the clade comprising fabids and malvids, clarifying the phylogenetic position of Zygophyllales at whole-genome scale. Analysis of genomic and transcriptomic data revealed multiple critical mechanisms underlying the efficient osmotic adjustment using Na+ and K+ as "cheap" osmolytes that Z. xanthoxylum has evolved through the expansion and synchronized expression of genes encoding key transporters/channels and their regulators involved in Na+/K+ uptake, transport, and compartmentation. It is worth noting that ZxCNGC1;1 (cyclic nucleotide-gated channels) and ZxCNGC1;2 constituted a previously undiscovered energy-saving pathway for Na+ uptake. Meanwhile, the core genes involved in biosynthesis of cuticular wax also featured an expansion and upregulated expression, contributing to the water retention capacity of Z. xanthoxylum under desert environments. Overall, these findings boost the understanding of evolutionary relationships of eudicots, illustrate the unique water retention mechanism in the succulent xerophyte that is distinct from glycophyte, and thus provide valuable genetic resources for the improvement of stress tolerance in crops and insights into the remediation of sodic lands.


Assuntos
Filogenia , Água , Zygophyllum , Água/metabolismo , Zygophyllum/genética , Zygophyllum/metabolismo , Genoma de Planta , Regulação da Expressão Gênica de Plantas , Genômica/métodos
3.
Nucleic Acids Res ; 51(15): 7972-7987, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37395399

RESUMO

DNA-dependent protein kinase (DNA-PK) plays a critical role in non-homologous end joining (NHEJ), the predominant pathway that repairs DNA double-strand breaks (DSB) in response to ionizing radiation (IR) to govern genome integrity. The interaction of the catalytic subunit of DNA-PK (DNA-PKcs) with the Ku70/Ku80 heterodimer on DSBs leads to DNA-PK activation; however, it is not known if upstream signaling events govern this activation. Here, we reveal a regulatory step governing DNA-PK activation by SIRT2 deacetylation, which facilitates DNA-PKcs localization to DSBs and interaction with Ku, thereby promoting DSB repair by NHEJ. SIRT2 deacetylase activity governs cellular resistance to DSB-inducing agents and promotes NHEJ. SIRT2 furthermore interacts with and deacetylates DNA-PKcs in response to IR. SIRT2 deacetylase activity facilitates DNA-PKcs interaction with Ku and localization to DSBs and promotes DNA-PK activation and phosphorylation of downstream NHEJ substrates. Moreover, targeting SIRT2 with AGK2, a SIRT2-specific inhibitor, augments the efficacy of IR in cancer cells and tumors. Our findings define a regulatory step for DNA-PK activation by SIRT2-mediated deacetylation, elucidating a critical upstream signaling event initiating the repair of DSBs by NHEJ. Furthermore, our data suggest that SIRT2 inhibition may be a promising rationale-driven therapeutic strategy for increasing the effectiveness of radiation therapy.


Assuntos
Quebras de DNA de Cadeia Dupla , Proteínas Quinases , DNA/genética , DNA/metabolismo , Reparo do DNA por Junção de Extremidades , Reparo do DNA , Proteína Quinase Ativada por DNA/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Autoantígeno Ku/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Quinases/genética , Sirtuína 2/genética , Sirtuína 2/metabolismo , Humanos
4.
J Org Chem ; 89(11): 8243-8248, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38753315

RESUMO

Herein we have pioneered an innovative synthetic strategy for the efficient assembly of various heteroarene-condensed benzofuran derivatives, utilizing benzofuran-derived azadienes (BDAs) and quinolines as the starting materials. This method functions with transition-metal catalysis and uses cost-effective formic acid as the reducing agent. Mechanistic investigations indicate that this transformation would involve a [4 + 2] annulation cascade process. This approach demonstrates a high tolerance to various functional groups and yields excellent results.

5.
Environ Sci Technol ; 58(27): 12008-12017, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38920967

RESUMO

International arsenic trade, physical and virtual, has resulted in considerable transfer of arsenic pollution across regions. However, no study has systematically captured, estimated, and compared physical and virtual arsenic trade and its relevant impacts. This study combines material flow analysis and embodied emission factors to estimate embedded (including direct and indirect trade) and embodied arsenic trade during 1990-2019, encompassing 18 arsenic-containing products among 244 countries. Global embedded arsenic trade increased considerably from 47 ± 7.3 to 450 ± 68 kilotonnes (kt) during this time and was dominated by indirect arsenic trade, contributing 94 and 90% to global arsenic trade in 1990 and 2019, respectively. Since the 1990s, global arsenic trade centers and the main flows have shifted from European and American markets to developing countries. The mass of arsenic involved in embodied trade increased from 87.5 ± 26 kt in 1990 to 800 ± 236 kt in 2019. Direct trade and indirect trade aggravate arsenic environmental emissions in major importing countries, like China, while embodied trade aggravates arsenic environmental emissions in major exporting countries, like Peru and Chile. The trade-related arsenic pollution transfer calls for a rational arsenic emission responsibility-sharing mechanism and corresponding policy recommendations for different trading countries.


Assuntos
Arsênio , Comércio , Poluição Ambiental
6.
J Nanobiotechnology ; 22(1): 24, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38191388

RESUMO

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.


Assuntos
Antibacterianos , Nanopartículas Magnéticas de Óxido de Ferro , Animais , Humanos
7.
Ecotoxicol Environ Saf ; 274: 116177, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38461573

RESUMO

Triphenyltin (TPT) is a typical persistent organic pollutant whose occurrence in coral reef ecosystems may threaten the survival of reef fishes. In this study, a brightly colored representative reef fish, Amphiprion ocellaris was used to explore the effects of TPT at environmental levels (1, 10, and 100 ng/L) on skin pigment synthesis. After the fish were exposed to TPT for 60 days, the skin became darker, owing to an increase in the relative area of black stripes, a decrease in orange color values while an increase in brown color values, and an increase in the number of melanocytes in the orange part of the skin tissues. To explore the mechanisms by which TPT induces darker body coloration, the enzymatic activity and gene expression levels of the members of melanocortin system that affect melanin synthesis were evaluated. Leptin levels and lepr expression were found to be increased after TPT exposure, which likely contributed to the increase found in pomc expression and α-melanocyte-stimulating hormone (α-MSH) levels. Then Tyr activity and mc1r, tyr, tyrp1, mitf, and dct were upregulated, ultimately increasing melanin levels. Importantly, RT-qPCR results were consistent with the transcriptome analysis of trends in lepr and pomc expression. Because the orange color values decreased, pterin levels and the pteridine metabolic pathway were also evaluated. The results showed that TPT induced BH4 levels and spr, xdh, and gch1 expression associated with pteridine synthesis decreased, ultimately decreasing the colored pterin content (sepiapterin). We conclude that TPT exposure interferes with the melanocortin system and pteridine metabolic pathway to increase melanin and decrease colored pterin levels, leading to darker body coloration in A. ocellaris. Given the importance of body coloration for the survival and reproduction of reef fishes, studies on the effects of pollutants (others alongside TPT) on body coloration are of high priority.


Assuntos
Melanocortinas , Compostos Orgânicos de Estanho , Perciformes , Animais , Pró-Opiomelanocortina , Ecossistema , Melaninas/genética , Pteridinas , Peixes/genética , Perciformes/genética , Pterinas , Redes e Vias Metabólicas
8.
Molecules ; 29(6)2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38542881

RESUMO

RNAs play crucial roles in various essential biological functions, including catalysis and gene regulation. Despite the widespread use of coarse-grained (CG) models/simulations to study RNA 3D structures and dynamics, their direct application is challenging due to the lack of atomic detail. Therefore, the reconstruction of full atomic structures is desirable. In this study, we introduced a straightforward method called ABC2A for reconstructing all-atom structures from RNA CG models. ABC2A utilizes diverse nucleotide fragments from known structures to assemble full atomic structures based on the CG atoms. The diversification of assembly fragments beyond standard A-form ones, commonly used in other programs, combined with a highly simplified structure refinement process, ensures that ABC2A achieves both high accuracy and rapid speed. Tests on a recent large dataset of 361 RNA experimental structures (30-692 nt) indicate that ABC2A can reconstruct full atomic structures from three-bead CG models with a mean RMSD of ~0.34 Å from experimental structures and an average runtime of ~0.5 s (maximum runtime < 2.5 s). Compared to the state-of-the-art Arena, ABC2A achieves a ~25% improvement in accuracy and is five times faster in speed.


Assuntos
Simulação de Dinâmica Molecular , RNA , RNA/química , Nucleotídeos
9.
Molecules ; 29(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38731462

RESUMO

A novel and efficient method for functionalizing organosulfones has been established, utilizing a visible-light-driven intermolecular radical cascade cyclization of α-allyl-ß-ketosulfones. This process employs fac-Ir(ppy)3 as the photoredox catalyst and α-carbonyl alkyl bromide as the oxidizing agent. Via this approach, the substrates experience intermolecular addition of α-carbonyl alkyl radicals to the alkene bonds, initiating a sequence of C-C bond formations that culminate in the production of organosulfone derivatives. Notably, this technique features gentle reaction conditions and an exceptional compatibility with a wide array of functional groups, making it a versatile and valuable addition to the field of organic synthesis.

10.
Biophys J ; 122(8): 1503-1516, 2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-36924021

RESUMO

RNA pseudoknots are a kind of important tertiary motif, and the structures and stabilities of pseudoknots are generally critical to the biological functions of RNAs with the motifs. In this work, we have carefully refined our previously developed coarse-grained model with salt effect through involving a new coarse-grained force field and a replica-exchange Monte Carlo algorithm, and employed the model to predict structures and stabilities of complex RNA pseudoknots in ion solutions beyond minimal H-type pseudoknots. Compared with available experimental data, the newly refined model can successfully predict 3D structures from sequences for the complex RNA pseudoknots including SARS-CoV-2 programming-1 ribosomal frameshifting element and Zika virus xrRNA, and can reliably predict the thermal stabilities of RNA pseudoknots with various sequences and lengths over broad ranges of monovalent/divalent salts. In addition, for complex pseudoknots including SARS-CoV-2 frameshifting element, our analyses show that their thermally unfolding pathways are mainly dependent on the relative stabilities of unfolded intermediate states, in analogy to those of minimal H-type pseudoknots.


Assuntos
COVID-19 , Infecção por Zika virus , Zika virus , Humanos , RNA/química , Conformação de Ácido Nucleico , SARS-CoV-2/genética , Cloreto de Sódio , Zika virus/genética , Zika virus/metabolismo
11.
BMC Plant Biol ; 23(1): 215, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37098482

RESUMO

BACKGROUND: Melatonin is considered to be a polyfunctional master regulator in animals and higher plants. Exogenous melatonin inhibits plant infection by multiple diseases; however, the role of melatonin in Cucumber green mottle mosaic virus (CGMMV) infection remains unknown. RESULTS: In this study, we demonstrated that exogenous melatonin treatment can effectively control CGMMV infection. The greatest control effect was achieved by 3 days of root irrigation at a melatonin concentration of 50 µM. Exogenous melatonin showed preventive and therapeutic effects against CGMMV infection at early stage in tobacco and cucumber. We utilized RNA sequencing technology to compare the expression profiles of mock-inoculated, CGMMV-infected, and melatonin+CGMMV-infected tobacco leaves. Defense-related gene CRISP1 was specifically upregulated in response to melatonin, but not to salicylic acid (SA). Silencing CRISP1 enhanced the preventive effects of melatonin on CGMMV infection, but had no effect on CGMMV infection. We also found exogenous melatonin has preventive effects against another Tobamovirus, Pepper mild mottle virus (PMMoV) infection. CONCLUSIONS: Together, these results indicate that exogenous melatonin controls two Tobamovirus infections and inhibition of CRISP1 enhanced melatonin control effects against CGMMV infection, which may lead to the development of a novel melatonin treatment for Tobamovirus control.


Assuntos
Melatonina , Tobamovirus , Reguladores de Crescimento de Plantas , Cisteína , Melatonina/farmacologia , Tobamovirus/genética , Nicotiana/genética , Doenças das Plantas/genética
12.
J Neuroinflammation ; 20(1): 22, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36737785

RESUMO

BACKGROUND: Postoperative pain is a serious clinical problem with a poorly understood mechanism, and lacks effective treatment. Hydrogen (H2) can reduce neuroinflammation; therefore, we hypothesize that H2 may alleviate postoperative pain, and aimed to investigate the underlying mechanism. METHODS: Mice were used to establish a postoperative pain model using plantar incision surgery. Mechanical allodynia was measured using the von Frey test. Cell signaling was assayed using gelatin zymography, western blotting, immunohistochemistry, and immunofluorescence staining. Animals or BV-2 cells were received with/without ASK1 and Trx1 inhibitors to investigate the effects of H2 on microglia. RESULTS: Plantar incision surgery increased MMP-9 activity and ASK1 phosphorylation in the spinal cord of mice. MMP-9 knockout and the ASK1 inhibitor, NQDI-1, attenuated postoperative pain. H2 increased the expression of Trx1 in the spinal cord and in BV-2 cells. H2 treatment mimicked NQDI1 in decreasing the phosphorylation of ASK1, p38 and JNK. It also reduced MMP-9 activity, downregulated pro-IL-1ß maturation and IBA-1 expression in the spinal cord of mice, and ameliorated postoperative pain. The protective effects of H2 were abolished by the Trx1 inhibitor, PX12. In vitro, in BV-2 cells, H2 also mimicked NQDI1 in inhibiting the phosphorylation of ASK1, p38, and JNK, and also reduced MMP-9 activity and decreased IBA-1 expression induced by LPS. The Trx1 inhibitor, PX12, abolished the protective effects of H2 in BV-2 cells. CONCLUSIONS: For the first time, the results of our study confirm that H2 can be used as a therapeutic agent to alleviate postoperative pain through the Trx1/ASK1/MMP9 signaling pathway. MMP-9 and ASK1 may be the target molecules for relieving postoperative pain.


Assuntos
Hidrogênio , Metaloproteinase 9 da Matriz , Animais , Camundongos , Metaloproteinase 9 da Matriz/metabolismo , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/metabolismo , Transdução de Sinais
13.
Clin Endocrinol (Oxf) ; 99(1): 92-102, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37029081

RESUMO

OBJECTIVE: Parapharyngeal metastases (PPM) are rarely observed in patients with well-differentiated thyroid cancer (WDTC). Radioiodine (131 I) therapy has been the main treatment for metastatic and recurrent DTC after thyroidectomy. This study was performed to evaluate the clinicopathological features and long-term outcomes associated with survival of patients with PPM at the end of follow-up. DESIGN: In total, 14,984 consecutive patients with DTC who underwent 131 I therapy after total or near-total thyroidectomy from 2004 to 2021 were retrospectively reviewed. Therapeutic efficacy was evaluated using the Response Evaluation Criteria in Solid Tumours v1.1 and logistic regression analysis. The disease status was determined using dynamic risk stratification. Disease-specific survival (DSS) was assessed using the Kaplan-Meier method and a Cox proportional hazards model. PATIENTS: Seventy-five patients with PPM from WDTC were enroled in this study. Their median age at the initial diagnosis of PPM was 40.2 ± 14.1 years, and the patients comprised 32 men and 43 women (male:female ratio, 1.00:1.34). Of the 75 patients, 43 (57.33%) presented with combined distant metastases. Fifty-seven (76.00%) patients had 131 I avidity and 18 had non-131 I avidity. At the end of follow-up, 22 (29.33%) patients showed progressive disease. Sixteen of the 75 patients died; of the remaining 59 patients, 6 (8.00%) had an excellent response, 6 (8.00%) had an indeterminate response, 10 (13.33%) had an biochemical incomplete response, and 37 (49.33%) had a structural incomplete response. Multivariate analysis confirmed that age at initial PPM diagnosis, the maximal size of PPM, and 131 I avidity had significant effects on progressive disease of PPM lesions (p = .03, p= .02, and p < .01, respectively). The 5- and 10-year DSS rates were 98.49% and 62.10%, respectively. Age of ≥55 years at initial diagnosis of PPM and the presence of concomitant distant metastasis were independently associated with a poor prognosis (p = .03 and p = .04, respectively). CONCLUSION: The therapeutic effect for PPM was closely associated with 131 I avidity, age at initial PPM diagnosis, and maximal size of PPM at the end of follow-up. Age of ≥55 years at initial diagnosis of PPM and the presence of concomitant distant metastasis were independently associated with poor survival.


Assuntos
Radioisótopos do Iodo , Neoplasias da Glândula Tireoide , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Prognóstico , Seguimentos , Radioisótopos do Iodo/uso terapêutico , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/patologia , Tireoidectomia
14.
Psychol Med ; 53(2): 351-361, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-33952359

RESUMO

BACKGROUND: People with serious mental illness are at great risk of suicide, but little is known about the suicide rates among this population. We aimed to quantify the suicide rates among people with serious mental illness (bipolar disorder, major depression, or schizophrenia). METHODS: PubMed and Web of Science were searched to identify studies published from 1 January 1975 to 10 December 2020. We assessed English-language studies for the suicide rates among people with serious mental illness. Random-effects meta-analysis was used. Changes in follow-up time and the suicide rates were presented by a locally weighted scatter-plot smoothing (LOESS) curve. Suicide rate ratio was estimated for assessments of difference in suicide rate by sex. RESULTS: Of 5014 identified studies, 41 were included in this analysis. The pooled suicide rate was 312.8 per 100 000 person-years (95% CI 230.3-406.8). Europe was reported to have the highest pooled suicide rate of 335.2 per 100 000 person-years (95% CI 261.5-417.6). Major depression had the highest suicide rate of 534.3 per 100 000 person-years (95% CI 30.4-1448.7). There is a downward trend in suicide rate estimates over follow-up time. Excess risk of suicide in males was found [1.90 (95% CI 1.60-2.25)]. The most common suicide method was poisoning [21.9 per 100 000 person-years (95% CI 3.7-50.4)]. CONCLUSIONS: The suicide rates among people with serious mental illness were high, highlighting the requirements for increasing psychological assessment and monitoring. Further study should focus on region and age differences in suicide among this population.


Assuntos
Transtorno Bipolar , Transtorno Depressivo Maior , Esquizofrenia , Suicídio , Masculino , Humanos , Esquizofrenia/epidemiologia , Europa (Continente)
15.
Chemphyschem ; 24(6): e202200769, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36420565

RESUMO

The gas-phase clusters reaction permits addressing fundamental aspects of the challenges related to C-H activation. The size effect plays a key role in the activation processes as it may substantially affect both the reactivity and selectivity. In this paper, we reviewed the size effect related to the hydrocarbon oxidation by early transition metal oxides and main group metal oxides, methane activation mediated by late transition metals. Based on mass-spectrometry experiments in conjunction with quantum chemical calculations, mechanistic discussions were reviewed to present how and why the size greatly regulates the reactivity and product distribution.

16.
PLoS Comput Biol ; 18(10): e1010501, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36260618

RESUMO

The three-dimensional (3D) structure and stability of DNA are essential to understand/control their biological functions and aid the development of novel materials. In this work, we present a coarse-grained (CG) model for DNA based on the RNA CG model proposed by us, to predict 3D structures and stability for both dsDNA and ssDNA from the sequence. Combined with a Monte Carlo simulated annealing algorithm and CG force fields involving the sequence-dependent base-pairing/stacking interactions and an implicit electrostatic potential, the present model successfully folds 20 dsDNAs (≤52nt) and 20 ssDNAs (≤74nt) into the corresponding native-like structures just from their sequences, with an overall mean RMSD of 3.4Å from the experimental structures. For DNAs with various lengths and sequences, the present model can make reliable predictions on stability, e.g., for 27 dsDNAs with/without bulge/internal loops and 24 ssDNAs including pseudoknot, the mean deviation of predicted melting temperatures from the corresponding experimental data is only ~2.0°C. Furthermore, the model also quantificationally predicts the effects of monovalent or divalent ions on the structure stability of ssDNAs/dsDNAs.


Assuntos
DNA , RNA , Conformação de Ácido Nucleico , RNA/química , DNA de Cadeia Simples , Íons
17.
J Phys Chem A ; 127(34): 7094-7100, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37595129

RESUMO

Effective CO2 hydrogenation has recently attracted quite some attention for producing more valuable chemical oxygenates (such as methanol, formate) in mild conditions. However, the influence of the metal center on the CO2 activation remains unclear. First, electrospray ionization mass spectrometry (ESI-MS) was employed to explore the direct CO2 hydrogenation to formic acid mediated by [Cp2MH]+ (M = Zr, Hf) in the gas phase at room temperature. The key formate intermediate [Cp2M(O2CH)]+ (M = Zr, Hf) was confirmed by traveling wave ion mobility spectrometry (TWIMS). Second, to gain insights into the metal effect, the CO2 hydrogenation process involving Group 4 (i.e., Ti, Zr, Hf) transition metals was calculated along with Group 5 (i.e., V, Nb, Ta) by density functional theory (DFT) methods. The CO2 insertion process was found to be the rate-limiting step. For [Cp2TiH]+, [Cp2ZrH]+, [Cp2HfH]+, [Cp2VH]+, [Cp2NbH]+, and [Cp2TaH]+, the barriers are +7.7, +6.5, +5.9, +9.2, +8.0, and +6.3 kcal/mol, respectively. [Cp2HfH]+-mediated CO2 hydrogenation occurs the most rapidly, as revealed by MS. According to the orbital analysis on the CO2 insertion transition state, the electron-deficient metal center resulting in a low-lying lowest unoccupied molecular orbital (LUMO) could interact more favorably with the π bond of deformed CO2, which was also consistent with the natural bond orbital (NBO) results. Last but not the least, NBO charges on the metal centers were found to correlate linearly well with the CO2 insertion barriers rather than hydride affinity. Thus, the reactivity of different metal hydride complexes with CO2 to produce a formate could be estimated by the NBO charge on metals. Our findings might provide a series of candidates for the catalyst as well as guidance for catalyst design in mild CO2 hydrogenation.

18.
J Nanobiotechnology ; 21(1): 247, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37528366

RESUMO

Lymph node metastasis is a frequent occurrence in a variety of tumour forms and poses an enormous challenge to cancer treatment. This process is critical to the development of the disease and is frequently linked to a poor prognosis. Over 90% of cancerous cells move through lymph nodes, making them important entry routes for the spread of cancer cells. The prognosis of cancer patients is significantly impacted by lymph node metastases, which also affects treatment choices. Targeting lymph node metastases presents numerous difficulties for conventional medication delivery techniques. It is still very difficult to selectively target cancer cells in lymph nodes without risking injury to healthy organs and unforeseen consequences. Additionally, systemic delivery of drugs is hampered by the slow flow rate of lymphatic vessels. Chemotherapeutic medicines' poor solubility and stability further reduce their effectiveness when taken orally. Additionally, the extracellular matrix that surrounds lymph node tumours is extensive, which makes it difficult for conventional pharmaceutical delivery systems to reach cancer cells. The development of nanocarriers for precise drug delivery to LNs has attracted a lot of interest to overcome these obstacles. Most solid tumours first spread through the lymphatic system, hence effective drug administration to these tissues is essential for better therapeutic results. Nanocarriers have several benefits, including the capacity to pass through barriers like blood-brain barriers and membranes to reach the lymphatic system. High medication dosages can be enclosed thanks to the physicochemical characteristics of nanocarriers, such as their higher surface-to-volume ratio. Additionally, ligands, antibodies, polymers, or biological molecules can be attached to nanocarrier surfaces to change their properties, allowing for the targeted delivery of lymph node epithelial cells. This use of nanocarriers for drug delivery maximizes on-target effects and related adverse effects while improving the effectiveness of medication delivery to target locations. More research and development in this field is needed to optimize nanocarrier design, increase targeting capabilities, and expand clinical applications for better cancer care.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas , Humanos , Metástase Linfática/patologia , Sistema Linfático , Linfonodos/patologia , Barreira Hematoencefálica , Nanopartículas/química
19.
Nephrology (Carlton) ; 28(3): 159-167, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36564906

RESUMO

AIM: To investigate the gender and socioeconomic disparities in the global burden of chronic kidney disease (CKD) due to glomerulonephritis from 1990 to 2019. METHODS: Data were extracted from the global burden of diseases (GBD) 2019 study, including incidence, prevalence and disability-adjusted life-years (DALYs). Estimated annual percentage changes (EAPCs) were calculated to quantify the temporal trends in age-standardized rate (ASR) of CKD due to glomerulonephritis. Paired t-test, paired Wilcoxon signed-rank test and Spearman correlation were performed to analyse the association and gender disparity in CKD due to glomerulonephritis. RESULTS: Globally, incident cases of CKD due to glomerulonephritis increased 81% from 9 557 397 in 1990 to 17 308 071 in 2019. The age-standardized incidence rate increased by 1.47 compared with 1990 and DALYs increased by 1.35 compared with 1990 (per 100 000). The number of patients with CKD due to glomerulonephritis in low-middle SDI (3829917) and middle SDI (6268817) regions accounts for more than 55% of the total cases. CKD due to glomerulonephritis caused a higher burden including the incidence rate (p < .0001) and DALY rate (p < .0001) in men compared to women. The age-standardized DALY rate was negatively correlated with SDI (ρ = -0.64, p < .001). In the analysis of risk factors for DALYs, male individuals had a larger burden of hypertension, high BMI and high sodium diet in the DALY rates than female subjects. CONCLUSION: The burden of CKD due to glomerulonephritis was more skewed towards developing and less developed economies and differed by gender, so certain nations should implement far more focused and targeted policies.


Assuntos
Insuficiência Renal Crônica , Disparidades Socioeconômicas em Saúde , Humanos , Masculino , Feminino , Anos de Vida Ajustados por Qualidade de Vida , Saúde Global , Carga Global da Doença , Incidência
20.
Molecules ; 28(12)2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37375388

RESUMO

DNA carries the genetic information required for the synthesis of RNA and proteins and plays an important role in many processes of biological development. Understanding the three-dimensional (3D) structures and dynamics of DNA is crucial for understanding their biological functions and guiding the development of novel materials. In this review, we discuss the recent advancements in computer methods for studying DNA 3D structures. This includes molecular dynamics simulations to analyze DNA dynamics, flexibility, and ion binding. We also explore various coarse-grained models used for DNA structure prediction or folding, along with fragment assembly methods for constructing DNA 3D structures. Furthermore, we also discuss the advantages and disadvantages of these methods and highlight their differences.


Assuntos
Simulação de Dinâmica Molecular , Proteínas , Proteínas/química , DNA/química , RNA/química , Dobramento de Proteína
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