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1.
Org Lett ; 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38661476

RESUMO

A novel ion exchange strategy has been developed to enable the asymmetric construction of axially chiral sulfone-containing styrenes. This approach provides a practical synthesis pathway for various axially chiral sulfone-containing styrenes with good yields, exceptional enantioselectivities, and nearly complete E/Z selectivities. Additionally, the reaction mechanism is elucidated in detail through density functional theory (DFT) calculations.

2.
Metabolites ; 14(4)2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38668309

RESUMO

In order to explore the regulating role and the physiological and biochemical mechanisms of trans-abscisic acid (hereinafter referred as S-ABA) in the process of rice growth and development under salt stress, we took Chaoyou 1000 and Yuxiangyouzhan as materials and set up three salt concentration treatments, CK0 (Control treatment), N1 (50 mmol L-1 NaCl), and N2 (100 mmol L-1 NaCl), in potted trials; we aimed to study the mechanism of rice's response to salt stress from the perspective of agricultural traits and physiological biochemicals and to improve rice's resistance to salt stress through exogenously applying the regulating technology of S-ABA. The following results were obtained: Under salt stress, the growth of rice was significantly suppressed compared to CK0, exhibiting notable increases in agricultural indicators, photosynthesis efficiency, and the NA+ content of leaves. However, we noted a significant decrease in the K+ content in the leaves, alongside a prominent increase in NA+/K+ and a big increase in MDA (malondialdehyde), H2O2 (hydrogen peroxide), and O2- (superoxide anion). This caused the cytomembrane permeability to deteriorate. By applying S-ABA under salt stress (in comparison with salt treatment), we promoted improvements in agronomic traits, enhanced photosynthesis, reduced the accumulation of NA+ in leaves, increased the K+ content and the activity of antioxidant enzymes, and reduced the active oxygen content, resulting in a sharp decrease in the impact of salt stress on rice's development. The application of S-ABA decreased the endogenous ABA (abscisic acid) content under salt stress treatment but increased the endogenous GA (gibberellin) and IAA (indole acetic acid) contents and maintained the hormonal homeostasis in rice plants. To summarize, salt stress causes damage to rice growth, and the exogenous application of S-ABA can activate the pouring system mechanism of rice, suppress the outbreak of active oxygen, and regulate NA+/K+ balance and hormone homeostasis in the blades, thus relieving the salt stress.

3.
Heliyon ; 10(7): e28593, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38576586

RESUMO

Background: Family involvement and comfort are equally important in palliative care. Dignity undertook a new meaning and novel challenges as a result of restrictions on visits and companionship during the pandemic. Family-centered family dignity interventions have been shown to be effective in increasing patients' sense of dignity, increasing levels of hope, and reducing psychological distress; however, the effectiveness in enhancing family adaptability and intimacy in the survivor-caregiver binary and reducing expected grief have been inconclusive. Objectives: The primary objective of this study was to assess the efficacy of family dignity interventions on family adaptability and cohesion. The secondary objective was to explore the effects of the interventions on anticipatory grief and psychological distress, and the lasting effect 1 month after the intervention. Design: A single-blinded, two-arm parallel group, randomized controlled trial was conducted in China. Settings: and methods: Ninety-eight dyads who met the inclusion criteria were randomly assigned to the family dignity intervention (n = 51) or standard palliative care group (n = 47) between June and August 2022. Study outcomes were measured at baseline, immediately post-intervention, and at the 1-month follow-up post-intervention evaluation. Data were analyzed using the Kolmogorov-Smirnov test, chi-square test, Fisher's exact test, independent sample t-test, Wilcoxon rank-sum test, and generalized estimation equations. The Intention-To-Treat analysis was performed for all available data. Results: In comparison to the control group, significant improvements in family adaptability and cohesion and anticipatory grief over post-intervention and 1-month follow-up were demonstrated among the patients in the intervention group. The intervention group of caregivers had significant improvement in anticipatory grief at post-intervention and 1-month follow-up. The level of psychological distress was significantly lower in the intervention group than the control group (p < 0.05) at 1-month follow-up but the differences were not statistically significant at post-intervention. All outcomes showed clear differences from baseline after the intervention and at the 1-month follow-up evaluation but not between post-intervention and at the 1-month follow-up evaluation. Conclusion: This study further verifies the actual effect of family dignity intervention program through randomized controlled trials, and provides a reference for improving the family relationship between advanced cancer patients and their family caregivers, and improving their mental health. The addition of family dignity intervention to standard palliative care greatly increased the adaptability and cohesion between survivors and their families, lessened the anticipatory grief of the survivor-caregiver pair, and relieved caregivers' anxiety and despair. We did not detect a statistically significant difference between post-intervention and the 1-month follow-up evaluation, suggesting that the intervention may have a durable impact at least 1 month.

4.
Adv Sci (Weinh) ; : e2306253, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38582510

RESUMO

The extensive application of nuclear technology has increased the potential of uncontrolled radiation exposure to the public. Since skin is the largest organ, radiation-induced skin injury remains a serious medical concern. Organisms evolutionally develop distinct strategies to protect against environment insults and the related research may bring novel insights into therapeutics development. Here, 26 increased peptides are identified in skin tissues of frogs (Pelophylax nigromaculatus) exposed to electron beams, among which four promoted the wound healing of irradiated skin in rats. Specifically, radiation-induced frog skin peptide-2 (RIFSP-2), from histone proteolysis exerted membrane permeability property, maintained cellular homeostasis, and reduced pyroptosis of irradiated cells with decreased TBK1 phosphorylation. Subsequently, stearyl-CoA desaturase 1 (SCD1) is identified, a critical enzyme in biogenesis of monounsaturated fatty acids (MUFAs) as a direct target of RIFSP-2 based on streptavidin-biotin system. The lipidomic analysis further assured the restrain of MUFAs biogenesis by RIFSP-2 following radiation. Moreover, the decreased MUFA limited radiation-induced and STING-mediated inflammation response. In addition, genetic depletion or pharmacological inhibition of STING counteracted the decreased pyroptosis by RIFSP-2 and retarded tissue repair process. Altogether, RIFSP-2 restrains radiation-induced activation of SCD1-MUFA-STING axis. Thus, the stress-induced amphibian peptides can be a bountiful source of novel radiation mitigators.

5.
Biochim Biophys Acta Mol Basis Dis ; 1870(5): 167196, 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38653358

RESUMO

RNA modification plays important roles in various physiological and pathological process. LAGE3 is a component of EKC/KEOPS complex, which is probably involved in the formation of a threonylcarbamoyl group on adenosine at position 37 (t(6)A37) in tRNAs, but its exact role in HCC is less studied. Our study reveals that LAGE3 exhibits upregulated expression in HCC compared with normal hepatocellular tissue. High expression of LAGE3 promotes hepatocellular cell proliferation and migration. Further investigations suggest that the increased expression of LAGE3 cloud lead to upregulated VEGFA secretion and angiogenesis in HCC. The mechanistic study reveals LAGE3 is required for the VEGFA mRNA stability. This research may open new avenues for diagnosis and targeted therapy in HCC.

6.
Radiat Res ; 201(4): 294-303, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38588381

RESUMO

Radiation-induced intestinal damage (RIID) is a common side effect of radiotherapy in patients with abdominopelvic malignancies. Gap junctions are special structures consisting of connexins (Cxs). This study aimed to investigate the expression and role of connexins in RIID and underlying mechanism. In this study, a calcein-AM fluorescence probe was used to detect changes in gap junctional intercellular communication in intestinal epithelial IEC-6 cells. Our results show that gap junctional intercellular communication of IEC-6 cells was reduced at 6, 12, 24, and 48 h after irradiation, with the most pronounced effect at 24 h. Western blotting and immunofluorescence results showed that the expression of Cx43, but not other connexins, was reduced in irradiated intestinal epithelial cells. Silencing of Cx43 reduced gap junctional intercellular communication between irradiated intestinal epithelial cells with increased ROS and intracellular Ca2+ levels. Furthermore, knockdown of Cx43 reduced the number of clonal clusters, decreased cell proliferation with increased cytotoxicity and apoptosis. Western blotting results showed that silencing of Cx43 resulted in changed γ-H2AX and PI3K/AKT pathway proteins in irradiated intestinal epithelial cells. Administration of the PI3K/AKT pathway inhibitor LY294002 inhibited the radioprotective effects in Cx43-overexpressing intestinal epithelial cells. Our study demonstrated that Cx43 expression is decreased by ionizing radiation, which facilitates the radioprotection of intestinal epithelial cells.


Assuntos
Conexina 43 , Proteínas Proto-Oncogênicas c-akt , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Cálcio/metabolismo , Conexinas/metabolismo , Conexinas/farmacologia , Transdução de Sinais , Junções Comunicantes , Comunicação Celular
7.
Chemosphere ; 357: 141951, 2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38626815

RESUMO

UV/Fe3+ and persulfate are two promising advanced oxidative degradation systems for in situ remediation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), yet a lack of comprehensive understanding of the degradation mechanisms. For the first time, we used density functional theory (DFT) to calculate the entire reaction pathways of the degradation of PFOA/PFOS in water by UV/Fe3+ and persulfate. In addition, we have deeply explored the different attack pathways driven by •OH and SO4-•, and found that SO4-• determines PFOA/PFOS to obtain PFOA/PFOS free radicals through single electron transfer to initiate the degradation reaction, while •OH determines the speed of PFOA/PFOS degradation reaction. Both degradation reactions were thermodynamically advantageous and kinetically feasible under calculated conditions. Based on the thermodynamic data, persulfate was found to be more favorable for the advanced oxidative degradation of Perfluorinated compounds (PFCs). Moreover, for SO4-• and •OH co-existing in the persulfate system, pH will affect the presence and concentration of these two types of free radicals, and low pH is not necessary for the degradation of PFOA/PFOS in the persulfate system. These results can considerably advance our understanding of the PFOA/PFOS degradation process in advanced oxidation processes (AOPs), which is driven by •OH and SO4-•. This study provides a DFT calculation process for the mechanism calculation of advanced oxidation degradation of other types of PFCs pollutants, hoping to elucidate the future development of PFCs removal. Further research should focus on determining the advanced oxidation degradation pathways of other types of PFCs, to support the development of computational studies on the advanced oxidation degradation of PFCs.

8.
Environ Int ; 185: 108535, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428192

RESUMO

Ultraviolet (UV) radiation is ubiquitous in the environment, which has been classified as an established human carcinogen. As the largest and outermost organ of the body, direct exposure of skin to sunlight or UV radiation can result in sunburn, inflammation, photo-immunosuppression, photoaging and even skin cancers. To date, there are tactics to protect the skin by preventing UV radiation and reducing the amount of UV radiation to the skin. Nevertheless, deciphering the essential regulatory mechanisms may pave the way for therapeutic interventions against UV-induced skin disorders. Additionally, UV light is considered beneficial for specific skin-related conditions in medical UV therapy. Recent evidence indicates that the biological effects of UV exposure extend beyond the skin and include the treatment of inflammatory diseases, solid tumors and certain abnormal behaviors. This review mainly focuses on the effects of UV on the skin. Moreover, novel findings of the biological effects of UV in other organs and systems are also summarized. Nevertheless, the mechanisms through which UV affects the human organism remain to be fully elucidated to achieve a more comprehensive understanding of its biological effects.


Assuntos
Dermatopatias , Neoplasias Cutâneas , Humanos , Raios Ultravioleta/efeitos adversos , Pele , Luz Solar , Neoplasias Cutâneas/prevenção & controle , Dermatopatias/etiologia
9.
Asia Pac J Oncol Nurs ; 11(4): 100389, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38495641

RESUMO

Objective: To explore the factors influencing family resilience in adult patients with acute leukemia undergoing chemotherapy, with the aim of providing a theoretical basis for the development of strategies to strengthen their family resilience. Methods: A descriptive phenomenological qualitative research method was used to select 11 adult acute leukemia chemotherapy patients for semi-structured interviews. Colaizzi 7-step analysis and NVivo 12.0 were used to summarize information and refine themes. Results: The main outcomes consisted of two themes and 11 sub-themes: protective factors for family resilience (positive traits, cognitive restructuring, positive family beliefs, organizational flexibility, clear communication, and social support) and risk factors for family resilience (symptom burden, self-concealment, role overload, economic distress, and social alienation). Conclusions: Health care professionals should pay attention to screening protective and risk factors for family resilience in adult acute leukemia chemotherapy patients, affirming the positive role of internal and external resources available in the family in stressful situations, alleviating patients' negative experiences, and promoting the recovery of family function.

10.
Artigo em Inglês | MEDLINE | ID: mdl-38509342

RESUMO

Diabetes currently affects approximately 500 million people worldwide and is one of the most common causes of mortality in the United States. To diagnose and monitor diabetes, finger-prick blood glucose testing has long been used as the clinical gold standard. For diabetes treatment, insulin is typically delivered subcutaneously through cannula-based syringes, pens, or pumps in almost all type 1 diabetic (T1D) patients and some type 2 diabetic (T2D) patients. These painful, invasive approaches can cause non-adherence to glucose testing and insulin therapy. To address these problems, researchers have developed miniaturized blood glucose testing devices as well as microfluidic platforms for non-invasive glucose testing through other body fluids. In addition, glycated hemoglobin (HbA1c), insulin levels, and cellular biomechanics-related metrics have also been considered for microfluidic-based diabetes diagnosis. For the treatment of diabetes, insulin has been delivered transdermally through microdevices, mostly through microneedle array-based, minimally invasive injections. Researchers have also developed microfluidic platforms for oral, intraperitoneal, and inhalation-based delivery of insulin. For T2D patients, metformin, glucagon-like peptide 1 (GLP-1), and GLP-1 receptor agonists have also been delivered using microfluidic technologies. Thus far, clinical studies have been widely performed on microfluidic-based diabetes monitoring, especially glucose sensing, yet technologies for the delivery of insulin and other drugs to diabetic patients with microfluidics are still mostly in the preclinical stage. This article provides a concise review of the role of microfluidic devices in the diagnosis and monitoring of diabetes, as well as the delivery of pharmaceuticals to treat diabetes using microfluidic technologies in the recent literature.

11.
Exp Neurol ; 376: 114750, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38492636

RESUMO

Nerve injury often leads to severe dysfunction because of the lack of axon regeneration in adult mammal. Intriguingly a series of extracellular vesicles (EVs) have the obvious ability to accelerate the nerve repair. However, the detailed molecular mechanisms to describe that EVs switch neuron from a transmitter to a regenerative state have not been elucidated. This study elucidated the microRNA (miRNA) expression profiles of two types of EVs that promote nerve regeneration. The functions of these miRNAs were screened in vitro. Among the 12 overlapping miRNAs, miR-25-3p was selected for further analysis as it markedly promoted axon regeneration both in vivo and in vitro. Furthermore, knockdown experiments confirmed that PTEN and Klf4, which are the major inhibitors of axon regeneration, were the direct targets of miR-25-3p in dorsal root ganglion (DRG) neurons. The utilization of luciferase reporter assays and functional tests provided evidence that miR-25-3p enhances axon regeneration by targeting Tgif1. Additionally, miR-25-3p upregulated the phosphorylation of Erk. Furthermore, Rapamycin modulated the expression of miR-25-3p in DRG neurons. Finally, the pro-axon regeneration effects of EVs were confirmed by overexpressing miR-25-3p and Tgif1 knockdown in the optic nerve crush model. Thus, the enrichment of miR-25-3p in EVs suggests that it regulates axon regeneration, proving a potential cell-free treatment strategy for nerve injury.

12.
Metabolites ; 14(3)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38535302

RESUMO

A large number of dead seedlings can occur in saline soils, which seriously affects the large-scale cultivation of rice. This study investigated the effects of plant growth regulators (PGRs) and nitrogen application on seedling growth and salt tolerance (Oryza sativa L.), which is of great significance for agricultural production practices. A conventional rice variety, "Huang Huazhan", was selected for this study. Non-salt stress treatments included 0% NaCl (CK treatment), CK + 0.05 g N/pot (N treatment), CK + 40 mg·L-1 5-aminolevulinic acid (5-ALA) (A treatment), and CK + 30 mg·L-1 diethylaminoethyl acetate (DTA-6) (D treatment). Salt stress treatments included 0.3% NaCl (S treatment), N + 0.3% NaCl (NS treatment), A + 0.3% NaCl (AS treatment), and D + 0.3% NaCl (DS treatment). When 3 leaves and 1 heart emerged from the soil, plants were sprayed with DTA-6 and 5-ALA, followed by the application of 0.3% NaCl (w/w) to the soil after 24 h. Seedling morphology and photosynthetic indices, as well as carbohydrate metabolism and key enzyme activities, were determined for each treatment. Our results showed that N, A, and D treatments promoted seedling growth, photosynthesis, carbohydrate levels, and the activities of key enzymes involved in carbon metabolism when compared to the CK treatment. The A treatment had the most significant effect, with increases in aboveground dry weight and net photosynthetic rates (Pn) ranging from 17.74% to 41.02% and 3.61% to 32.60%, respectively. Stomatal limiting values (Ls) significantly decreased from 19.17% to 43.02%. Salt stress significantly inhibited seedling growth. NS, AS, and DS treatments alleviated the morphological and physiological damage of salt stress on seedlings when compared to the S treatment. The AS treatment was the most effective in improving seedling morphology, promoting photosynthesis, increasing carbohydrate levels, and key enzyme activities. After AS treatment, increases in aboveground dry weight, net photosynthetic rate, soluble sugar content, total sucrose synthase, and amylase activities were 17.50% to 50.79%, 11.39% to 98.10%, 20.20% to 80.85%, 21.21% to 33.53%, and 22.17% to 34.19%, respectively, when compared to the S treatment. In summary, foliar sprays of 5-ALA, DTA-6, and additional nitrogen fertilizer enhanced rice seedling growth, increased photosynthesis, lowered Ls values, and improved seedling salt tolerance. Spraying two regulators, 5-ALA and DTA-6, quantitatively increased the effect of nitrogen fertilizer, with comparable effects on NaCl stress regulation. This study provides the basis for efficient agricultural production.

13.
Cancer Commun (Lond) ; 44(3): 297-360, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38311377

RESUMO

Cancer is a leading cause of death worldwide. Targeted therapies aimed at key oncogenic driver mutations in combination with chemotherapy and radiotherapy as well as immunotherapy have benefited cancer patients considerably. Tumor protein p53 (TP53), a crucial tumor suppressor gene encoding p53, regulates numerous downstream genes and cellular phenotypes in response to various stressors. The affected genes are involved in diverse processes, including cell cycle arrest, DNA repair, cellular senescence, metabolic homeostasis, apoptosis, and autophagy. However, accumulating recent studies have continued to reveal novel and unexpected functions of p53 in governing the fate of tumors, for example, functions in ferroptosis, immunity, the tumor microenvironment and microbiome metabolism. Among the possibilities, the evolutionary plasticity of p53 is the most controversial, partially due to the dizzying array of biological functions that have been attributed to different regulatory mechanisms of p53 signaling. Nearly 40 years after its discovery, this key tumor suppressor remains somewhat enigmatic. The intricate and diverse functions of p53 in regulating cell fate during cancer treatment are only the tip of the iceberg with respect to its equally complicated structural biology, which has been painstakingly revealed. Additionally, TP53 mutation is one of the most significant genetic alterations in cancer, contributing to rapid cancer cell growth and tumor progression. Here, we summarized recent advances that implicate altered p53 in modulating the response to various cancer therapies, including chemotherapy, radiotherapy, and immunotherapy. Furthermore, we also discussed potential strategies for targeting p53 as a therapeutic option for cancer.


Assuntos
Neoplasias , Proteína Supressora de Tumor p53 , Humanos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Amigos , Genes p53 , Mutação , Neoplasias/genética , Neoplasias/terapia , Microambiente Tumoral
14.
Lab Chip ; 24(6): 1586-1601, 2024 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-38362645

RESUMO

The rapid advancement in the fabrication and culture of in vitro organs has marked a new era in biomedical research. While strides have been made in creating structurally diverse bioartificial organs, such as the liver, which serves as the focal organ in our study, the field lacks a uniform approach for the predictive assessment of liver function. Our research bridges this gap with the introduction of a novel, machine-learning-based "3P model" framework. This model draws on a decade of experimental data across diverse culture platform studies, aiming to identify critical fabrication parameters affecting liver function, particularly in terms of albumin and urea secretion. Through meticulous statistical analysis, we evaluated the functional sustainability of the in vitro liver models. Despite the diversity of research methodologies and the consequent scarcity of standardized data, our regression model effectively captures the patterns observed in experimental findings. The insights gleaned from our study shed light on optimizing culture conditions and advance the evaluation of the functional maintenance capacity of bioartificial livers. This sets a precedent for future functional evaluations of bioartificial organs using machine learning.


Assuntos
Órgãos Bioartificiais , Fígado Artificial , Fígado , Albuminas
15.
Radiat Res ; 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38376467

RESUMO

Radiation-induced intestinal damage (RIID) is a common side effect of radiotherapy in patients with abdominopelvic malignancies. Gap junctions are special structures consisting of connexins (Cxs). This study aimed to investigate the expression and role of connexins in RIID and underlying mechanism. In this study, a calcein-AM fluorescence probe was used to detect changes in gap junctional intercellular communication in intestinal epithelial IEC-6 cells. Our results show that gap junctional intercellular communication of IEC-6 cells was reduced at 6, 12, 24, and 48 h after irradiation, with the most pronounced effect at 24 h. Western blotting and immunofluorescence results showed that the expression of Cx43, but not other connexins, was reduced in irradiated intestinal epithelial cells. Silencing of Cx43 reduced gap junctional intercellular communication between irradiated intestinal epithelial cells with increased ROS and intracellular Ca2+ levels. Furthermore, knockdown of Cx43 reduced the number of clonal clusters, decreased cell proliferation with increased cytotoxicity and apoptosis. Western blotting results showed that silencing of Cx43 resulted in changed γ-H2AX and PI3K/AKT pathway proteins in irradiated intestinal epithelial cells. Administration of the PI3K/AKT pathway inhibitor LY294002 inhibited the radioprotective effects in Cx43-overexpressing intestinal epithelial cells. Our study demonstrated that Cx43 expression is decreased by ionizing radiation, which facilitates the radioprotection of intestinal epithelial cells.

16.
Sci Total Environ ; 918: 170549, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38309335

RESUMO

Vegetation is vital to the ecosystem, contributing to the global carbon balance, but susceptible to the impacts of climate change. Monitoring vegetation drought remains challenging due to the lack of widely accepted drought indices. This study focused on vegetation, and simulated the vegetation suitable water demand and soil available water supply (calculated by Remote-sensing-based Water Balance Assessment Tool model). The standardized Vegetation Water deficit Index (SVWDI) was established by calculating the vegetation water deficit, which reflects the response of vegetation to drought. We examined the spatiotemporal evolution of vegetation drought on the Loess Plateau and evaluated the applicability of standardized vegetation water deficit index. Our findings revealed that the standardized vegetation water deficit index demonstrated an overall upward trend across different time scales from 1991 to 2020. Drought conditions were concentrated in the first 20 years of the study period, but vegetation drought on the Loess Plateau has been alleviated in the past decade. Moreover, as the time scale extended, the trend of SVWDI generally decreased, with approximately 49.50 % (1-month scale), 46.66 % (3-month scale), 47.08 % (12-month scale), and 32.16 % (24-month scale) of the grid areas experiencing increased SVWDI. The correlation between SVWDI and tree-ring width index (TRWI) performed well under all precipitation gradients, but the Palmer drought severity index (PDSI) was only highly correlated with TRWI in regions with low precipitation. In terms of the relationship with vegetation health, SVWDI demonstrated the highest correlation with the normalized difference vegetation index (NDVI) across different time scales, followed by PDSI and standardized precipitation evapotranspiration index (SPEI). This study provides insights into the evolution of vegetation drought in response to climate change. The findings can guide initiatives such as returning farmland to forest and grassland on the Loess Plateau to aid climate change adaptation strategies.


Assuntos
Secas , Ecossistema , Água , Solo , Florestas , Plantas , Árvores , Mudança Climática , China
18.
Nat Commun ; 15(1): 1483, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38374064

RESUMO

Aliphatic allylic amines are common in natural products and pharmaceuticals. The oxidative intermolecular amination of C(sp3)-H bonds represents one of the most straightforward strategies to construct these motifs. However, the utilization of widely internal alkenes with amines in this transformation remains a synthetic challenge due to the inefficient coordination of metals to internal alkenes and excessive coordination with aliphatic and aromatic amines, resulting in decreasing the reactivity of the catalyst. Here, we present a regioselective Cu-catalyzed oxidative allylic C(sp3)-H amination of internal olefins with azodiformates to these problems. A removable bidentate directing group is used to control the regiochemistry and stabilize the π-allyl-metal intermediate. Noteworthy is the dual role of azodiformates as both a nitrogen source and an electrophilic oxidant for the allylic C-H activation. This protocol features simple conditions, remarkable scope and functional group tolerance as evidenced by >40 examples and exhibits high regioselectivity and excellent E/Z selectivity.

19.
Anal Chim Acta ; 1287: 342138, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38182399

RESUMO

To detect the antioxidant capacity in living organisms, an antioxidation-responsive SERS-active microneedle was fabricated by adsorbing resazurin on miniature SERS substrates, SERS-active microneedles. The SERS intensity ratio of characterized peaks of resazurin and its product, resorufin, was adopted and verified as an indicator of antioxidant capacity. The feasibility of detection of the antioxidant capacity in living organisms was proved by using the fabricated SERS-active microneedles to detect the antioxidant capacity of lipopolysaccharide-induce inflammatory animal models. The fabricated SERS-active microneedles can be inserted into target soft tissues with minimal invasion to detect their antioxidant capacity. The fabricated SERS-active microneedles would be a novel tool to bring the detection of antioxidant capacity from samplings ex vivo and cells to complex tissues to promote the researches on redox biology in living organisms.


Assuntos
Antioxidantes , Lipopolissacarídeos , Animais , Modelos Animais
20.
J Cell Biol ; 223(2)2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-38252411

RESUMO

STK19 was originally identified as a manganese-dependent serine/threonine-specific protein kinase, but its function has been highly debated. Here, the crystal structure of STK19 revealed that it does not contain a kinase domain, but three intimately packed winged helix (WH) domains. The third WH domain mediated homodimerization and double-stranded DNA binding, both being important for its nuclear localization. STK19 participated in the nucleotide excision repair (NER) and mismatch repair (MMR) pathways by recruiting damage repair factors such as RPA2 and PCNA. STK19 also bound double-stranded RNA through the DNA-binding interface and regulated the expression levels of many mRNAs. Furthermore, STK19 knockdown cells exhibited very slow cell proliferation, which cannot be rescued by dimerization or DNA-binding mutants. Therefore, this work concludes that STK19 is highly unlikely to be a kinase but a DNA/RNA-binding protein critical for DNA damage repair (DDR) and cell proliferation. To prevent further confusions, we renamed this protein as TWH19 (Tandem Winged Helix protein formerly known as STK19).


Assuntos
Proliferação de Células , Reparo do DNA , Proteínas Nucleares , Processamento de Proteína Pós-Traducional , Proteínas Serina-Treonina Quinases , Dano ao DNA , Fosforilação , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Nucleares/metabolismo , Estrutura Terciária de Proteína
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