Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 238
Filtrar
1.
Mol Biol Evol ; 41(7)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38842255

RESUMO

The origins and extreme morphological evolution of the modern dog breeds are poorly studied because the founder populations are extinct. Here, we analyse eight 100 to 200 years old dog fur samples obtained from traditional North Swedish clothing, to explore the origin and artificial selection of the modern Nordic Lapphund and Elkhound dog breeds. Population genomic analysis confirmed the Lapphund and Elkhound breeds to originate from the local dog population, and showed a distinct decrease in genetic diversity in agreement with intense breeding. We identified eleven genes under positive selection during the breed development. In particular, the MSRB3 gene, associated with breed-related ear morphology, was selected in all Lapphund and Elkhound breeds, and functional assays showed that a SNP mutation in the 3'UTR region suppresses its expression through miRNA regulation. Our findings demonstrate analysis of near-modern dog artifacts as an effective tool for interpreting the origin and artificial selection of the modern dog breeds.


Assuntos
Pelo Animal , Seleção Genética , Animais , Cães/genética , Polimorfismo de Nucleotídeo Único , Cruzamento , Suécia , Variação Genética , MicroRNAs/genética
2.
Apoptosis ; 29(7-8): 981-1006, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38824478

RESUMO

Copper is a trace element required by the organism, but once the level of copper exceeds the threshold, it becomes toxic and even causes death. The underlying mechanisms of copper-induced death are inconclusive, with different studies showing different opinions on the mechanism of copper-induced death. Multiple investigations have shown that copper induces oxidative stress, endoplasmic reticulum stress, nucleolar stress, and proteasome inhibition, all of which can result in cell death. The latest research elucidates a copper-dependent death and denominates it as cuproptosis. Cuproptosis takes place through the combination of copper and lipoylated proteins of the tricarboxylic acid cycle, triggering agglomeration of lipoylated proteins and loss of iron-sulfur cluster proteins, leading to proteotoxic stress and ultimately death. Given the toxicity and necessity of copper, abnormal levels of copper lead to diseases such as neurological diseases and cancer. The development of cancer has a high demand for copper, neurological diseases involve the change of copper contents and the binding of copper to proteins. There is a close relationship between these two kinds of diseases and copper. Here, we summarize the mechanisms of copper-related death, and the association between copper and diseases, to better figure out the influence of copper in cell death and diseases, thus advancing the clinical remedy of these diseases.


Assuntos
Cobre , Neoplasias , Humanos , Cobre/metabolismo , Animais , Neoplasias/metabolismo , Neoplasias/patologia , Estresse Oxidativo , Estresse do Retículo Endoplasmático , Morte Celular , Apoptose , Doenças do Sistema Nervoso/metabolismo , Doenças do Sistema Nervoso/patologia
3.
Plant Physiol ; 191(2): 957-973, 2023 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-36459464

RESUMO

The photosynthetic mechanism of crop yields in fluctuating light environments in the field remains controversial. To further elucidate this mechanism, we conducted field and simulation experiments using maize (Zea mays) plants. Increased planting density enhanced the light fluctuation frequency and reduced the duration of daily high light, as well as the light-saturated photosynthetic rate, biomass, and yield per plant. Further analysis confirmed a highly significant positive correlation between biomass and yield per plant and the duration of photosynthesis related to daily high light. The simulation experiment indicated that the light-saturated photosynthetic rate of maize leaves decreased gradually and considerably when shortening the daily duration of high light. Under an identical duration of high light exposure, increasing the fluctuation frequency decreased the light-saturated photosynthetic rate slightly. Proteomic data also demonstrated that photosynthesis was mainly affected by the duration of high light and not by the light fluctuation frequency. Consequently, the current study proposes that an appropriate duration of daily high light under fluctuating light environments is the key factor for greatly improving photosynthesis. This is a promising mechanism by which the photosynthetic productivity and yield of maize can be enhanced under complex light environments in the field.


Assuntos
Proteômica , Zea mays , Fotossíntese , Biomassa , Folhas de Planta , Luz
4.
Plant Cell Environ ; 47(7): 2410-2425, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38517937

RESUMO

Bainong sterility (BNS) is a thermo-sensitive genic male sterile wheat line, characterised by anther fertility transformation in response to low temperature (LT) stress during meiosis, the failure of vacuole decomposition and the absence of starch accumulation in sterile bicellular pollen. Our study demonstrates that the late microspore (LM) stage marks the transition from the anther growth to anther maturation phase, characterised by the changes in anther structure, carbohydrate metabolism and the main transport pathway of sucrose (Suc). Fructan is a main storage polysaccharide in wheat anther, and its synthesis and remobilisation are crucial for anther development. Moreover, the process of pollen amylogenesis and the fate of the large vacuole in pollen are closely intertwined with fructan synthesis and remobilisation. LT disrupts the normal physiological metabolism of BNS anthers during meiosis, particularly affecting carbohydrate metabolism, thus determining the fate of male gametophytes and pollen abortion. Disruption of fructan synthesis and remobilisation regulation serves as a decisive event that results in anther abortion. Sterile pollen exhibits common traits of pollen starvation and impaired starch accumulation due to the inhibition of apoplastic transport starting from the LM stage, which is regulated by cell wall invertase TaIVR1 and Suc transporter TaSUT1.


Assuntos
Metabolismo dos Carboidratos , Flores , Infertilidade das Plantas , Pólen , Triticum , Triticum/genética , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Triticum/fisiologia , Infertilidade das Plantas/genética , Pólen/crescimento & desenvolvimento , Pólen/genética , Pólen/metabolismo , Flores/crescimento & desenvolvimento , Flores/genética , Flores/fisiologia , Flores/metabolismo , Amido/metabolismo , Sacarose/metabolismo , Frutanos/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
5.
Artigo em Inglês | MEDLINE | ID: mdl-38401082

RESUMO

Objective: This study aimed to assess the impact of combined moxibustion therapy and Gua sha on enhancing functional independence, reducing fall risk, and alleviating pain in patients undergoing post-rehabilitation for multiple cerebral infarctions. Methods: In a prospective clinical trial, 67 patients diagnosed with multiple cerebral infarctions (age range: 40 to 93 years) were enrolled. Baseline health characteristics included a median hospital stay of 10 days, prevalent medical conditions such as hypertension (64.18%), and various comorbidities like spondylosis (17.91%) and heart disease (14.93%). Patients received moxibustion treatment daily for 20-30 minutes on specific acupoints of the upper and lower extremities. Additionally, Gua sha therapy targeting the the head, back, chest, abdomen, and selected acupoints was administered twice a week with an interval of 3 to 4 days. Assessments included Barthel Index (BI) for functional independence, Morse Fall Scale (MFS) for fall risk, and Visual Analogue Scale (VAS) for pain intensity before and after the intervention. Results: After one week of rehabilitation, significant improvements were observed in the patient's functional independence, as indicated by a median BI score of 100 (IQR: 95-100), compared to the pre-rehabilitation median score of 95 (IQR: 90-100). The MFS score also showed a significant decrease after rehabilitation, with a median score of 35 (IQR: 35-45) compared to the pre-rehabilitation median score of 45 (IQR: 35-45). Additionally, pain intensity significantly decreased, with a median VAS score of 0 (range: 0-2) after rehabilitation, compared to the pre-rehabilitation median score of 0 (range: 0-3). Conclusion: Combined moxibustion therapy and Gua sha demonstrated positive effects on functional independence, fall risk reduction, and pain alleviation in post-rehabilitation for multiple cerebral infarctions. These findings suggest the potential of moxibustion and Gua sha as complementary interventions in stroke rehabilitation. The observed improvements in functional independence, fall risk, and pain underscore the potential benefits of these therapies for patients with multiple cerebral infarctions. Further exploration could delve into long-term effects, larger-scale trials, and mechanistic studies to elucidate the underlying pathways of efficacy.

6.
RNA Biol ; 20(1): 311-322, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-37294214

RESUMO

The exon junction complex (EJC) plays key roles throughout the lifespan of RNA and is particularly relevant in the nervous system. We investigated the roles of two EJC members, the paralogs MAGOH and MAGOHB, with respect to brain tumour development. High MAGOH/MAGOHB expression was observed in 14 tumour types; glioblastoma (GBM) showed the greatest difference compared to normal tissue. Increased MAGOH/MAGOHB expression was associated with poor prognosis in glioma patients, while knockdown of MAGOH/MAGOHB affected different cancer phenotypes. Reduced MAGOH/MAGOHB expression in GBM cells caused alterations in the splicing profile, including re-splicing and skipping of multiple exons. The binding profiles of EJC proteins indicated that exons affected by MAGOH/MAGOHB knockdown accumulated fewer complexes on average, providing a possible explanation for their sensitivity to MAGOH/MAGOHB knockdown. Transcripts (genes) showing alterations in the splicing profile are mainly implicated in cell division, cell cycle, splicing, and translation. We propose that high MAGOH/MAGOHB levels are required to safeguard the splicing of genes in high demand in scenarios requiring increased cell proliferation (brain development and GBM growth), ensuring efficient cell division, cell cycle regulation, and gene expression (splicing and translation). Since differentiated neuronal cells do not require increased MAGOH/MAGOHB expression, targeting these paralogs is a potential option for treating GBM.


Assuntos
Genes cdc , Glioblastoma , Humanos , Splicing de RNA , Divisão Celular , Núcleo Celular/metabolismo , Glioblastoma/metabolismo , Proteínas Nucleares/metabolismo
7.
Environ Sci Technol ; 57(14): 5806-5820, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-36996132

RESUMO

By developing a filtering framework and a sector-level multi-regional input-output structural decomposition model, this study identifies key common emission sources, motivation sources, and inter-provincial emission flows of both GHGs and air pollutants and reveals the key driving forces of changes in different emissions from 2012 to 2017. Results show that key common emission sources are electricity sector, non-metallic mineral products, and smelting and processing of metals in Shandong and Hebei. However, key common motivation sources are the construction sectors in Guangdong, Henan, Jiangsu, Zhejiang, and Shandong. The key inflow regions include Guangdong and Zhejiang and key outflow regions include Jiangsu and Hebei. The emission reductions are attributed to the emission intensity effect of the construction sector; contrastingly, the emission increase is from the investment scale of the construction sector. Here, Jiangsu could be a key target for future emission reduction because of its high absolute emissions and low past reduction. The scale of investment in construction might be a significant factor in reducing emissions in Shandong and Guangdong. Henan and Zhejiang could concentrate on sound new building planning and resource recycling.


Assuntos
Poluentes Atmosféricos , Gases de Efeito Estufa , Poluentes Atmosféricos/análise , China
8.
BMC Med Imaging ; 23(1): 131, 2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37715139

RESUMO

OBJECTIVE: To identify CT features and establish a nomogram, compared with a machine learning-based model for distinguishing gastrointestinal heterotopic pancreas (HP) from gastrointestinal stromal tumor (GIST). MATERIALS AND METHODS: This retrospective study included 148 patients with pathologically confirmed HP (n = 48) and GIST (n = 100) in the stomach or small intestine that were less than 3 cm in size. Clinical information and CT characteristics were collected. A nomogram on account of lasso regression and multivariate logistic regression, and a RandomForest (RF) model based on significant variables in univariate analyses were established. Receiver operating characteristic (ROC) curve, mean area under the curve (AUC), calibration curve and decision curve analysis (DCA) were carried out to evaluate and compare the diagnostic ability of models. RESULTS: The nomogram identified five CT features as independent predictors of HP diagnosis: age, location, LD/SD ratio, duct-like structure, and HU lesion/pancreas A. Five features were included in RF model and ranked according to their relevance to the differential diagnosis: LD/SD ratio, HU lesion/pancreas A, location, peritumoral hypodensity line and age. The nomogram and RF model yielded AUC of 0.951 (95% CI: 0.842-0.993) and 0.894 (95% CI: 0.766-0.966), respectively. The DeLong test found no statistically significant difference in diagnostic performance (p > 0.05), but DCA revealed that the nomogram surpassed the RF model in clinical usefulness. CONCLUSION: Two diagnostic prediction models based on a nomogram as well as RF method were reliable and easy-to-use for distinguishing between HP and GIST, which might also assist treatment planning.


Assuntos
Tumores do Estroma Gastrointestinal , Humanos , Tumores do Estroma Gastrointestinal/diagnóstico por imagem , Nomogramas , Estudos Retrospectivos , Pâncreas/diagnóstico por imagem , Aprendizado de Máquina , Tomografia Computadorizada por Raios X
9.
BMC Musculoskelet Disord ; 24(1): 896, 2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-37980477

RESUMO

BACKGROUND: Patellofemoral pain (PFP) is one of the most common disorders of the knee joint. Home-based exercise is an effective intervention to achieve self-management for chronic diseases. This study evaluated the effects of home-based exercise and health education in patients with PFP. METHODS: Patients who had PFP were randomly allocated to an intervention group (IG) or control group (CG). Patients in the IG received a 6-week tailored home-based exercise program with health education via remote support, while patients in the CG group only received health education. Clinical outcomes were compared using the Anterior Knee Pain Scale (AKPS) to measure function and the Visual Analog Scale (VAS) to measure "worst pain" and "pain with daily activity". Muscle strength was measured according to the peak torque of the knee muscles using an isokinetic system. RESULTS: Among a total of 112 participants screened for eligibility, 38 were randomized and analyzed, including 19 participants in the intervention group and 19 participants in the control group. There were no significant differences in baseline characteristics between the groups. At 6-week follow-up, the intervention group showed a greater worst pain reduction (between-group difference, -19.3 [95%CI, -23.2 to -15.5]; P < 0.01) and pain with daily activity (between-group difference, -22.9 [95%CI, -28.3 to -17.4]; P < 0.01) than the control group. Similarly, the intervention group had better improvements in AKPS (between-group difference, 9.0 [95%CI, 4.1 to 13.9]; P < 0.01) and knee extensor strength (between-group difference, 20.1 [95%CI, 14.5 to 25.8]; P < 0.01), compared to the control group. No adverse events were reported. CONCLUSION: Home-based exercise and health education resulted in less pain, better function, and higher knee muscle strength compared with no exercise in patients with PFP. A large randomized controlled trial with long-term follow-up is required to confirm these findings. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200056224 ( https://www.chictr.org.cn/showproj.aspx?proj=135506 ). Registered on February 1, 2022.


Assuntos
Síndrome da Dor Patelofemoral , Humanos , Síndrome da Dor Patelofemoral/diagnóstico , Síndrome da Dor Patelofemoral/terapia , Terapia por Exercício/métodos , Articulação do Joelho , Joelho , Dor
10.
Molecules ; 28(20)2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37894679

RESUMO

Cyanobacteria outbreaks are serious water pollution events, causing water crises around the world. Photocatalytic disinfection, as an effective approach, has been widely used to inhibit blue algae growth. In this study, a tiny reaction room containing a TiO2 film was designed to fulfill in situ optical observation of the destruction process of a one-dimensional multicellular microorganism, Anabaena sp. PCC 7120, which is also a typical bacterial strain causing water blooms. It was found that the fragment number increased exponentially with the activation time. The fracture mechanics of the algae chains were hypothesized to be the combining functions of increased local tensile stress originated from the cell contracting as well as the oxidative attacks coming from reactive oxygen species (ROSs). It was assumed that the oxidative species were the root cause of cellular structure changes in and chain fractures of Anabaena sp. PCC 7120 in the photocatalytic inactivation activity.


Assuntos
Anabaena , Cianobactérias , Anabaena/metabolismo , Cianobactérias/metabolismo , Titânio/farmacologia , Água , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica
11.
Neurochem Res ; 47(12): 3583-3597, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36322368

RESUMO

Postoperative neurocognitive disorder (PND) is a disease that frequently develops in older patients during the perioperative period. It seriously affects the quality of life of the affected patients. Despite advancements in understanding PND, this disorder's mechanisms remain unclear, including pathophysiological processes such as central synaptic plasticity and function, neuroinflammation, excitotoxicity, and neurotrophic support. Growing evidence suggests that microenvironmental changes are major factors for PND induction in older individuals. Exosomes are carriers for transporting different bioactive molecules between nerve cells in the microenvironment and maintaining intercellular communication and tissue homeostasis. Studies have shown that exosomes and microRNAs (miRNAs) are involved in various physiological and pathological processes, including neural processes related to PND, such as neurogenesis and cell death, neuroprotection, and neurotrophy. This article reviews the effects of exosomes and miRNAs on the brain microenvironment in PND and has important implications to improve PND diagnosis, as well as to develop targeted therapy of this disorder.


Assuntos
Exossomos , MicroRNAs , Humanos , Idoso , Exossomos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Qualidade de Vida , Comunicação Celular , Transtornos Neurocognitivos/genética , Transtornos Neurocognitivos/metabolismo
12.
Cell Mol Biol (Noisy-le-grand) ; 67(4): 334-339, 2022 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35809271

RESUMO

Endometriosis is a gynecological disease that endometrial cells develop outside the uterus. This event happens when the endometrial glands grow outside the endometrium and uterine muscles, especially in the pelvis. Although endometriosis is widespread, the clinical manifestations of the disease are very different, and it is challenging to adapt to the conventional classification system to divide patients into homogeneous groups. Given the importance of endometriosis, a correct, accurate, and timely diagnosis of this disease can significantly prevent its complications. Using health-related software is one of these ways. Enhanced Endometriosis Archiving Software (ENEAS) is a web-based application based on one of the most widely used open-source database management systems (MySQL), allowing the direct link to other open-source software for data management and storage. In the current study, the effect of ENEAS application was considered in patients with endometriosis, and its influence on IL-8 and MCP-1 gene expression was evaluated. For this purpose, 100 women with endometriosis were divided into two groups of 50 patients. The first group (control group) was examined by a gynecologist and received medication and treatment. In the case group, their demographic and clinical information were entered into ENEAS software. To study the expression of the IL-8 gene and MCP-1 gene, after collecting 5 ml of blood samples in tubes containing anticoagulant, RNA extraction was performed by Total RNA Purification Kit (Cat. 17200, 37500, 17250). Then cDNA synthesis was performed for this purpose, and a Bioneer DNA synthesis kit (South Korea) was used. The results showed that the expression level of the IL-8 gene in the case group was significantly reduced compared to the control group (P = 0.035). MCP-1 gene expression was also decreased compared to the control group, but this decrease was not significant. Therefore, those who used this application for treatment had reduced expression of IL-8 and MCP-1 genes. This event indicates that this application has reduced the amount of inflammation caused by endometriosis with proper analysis.


Assuntos
Endometriose , Endometriose/tratamento farmacológico , Endometriose/genética , Endométrio/metabolismo , Feminino , Humanos , Interleucina-8/genética , Interleucina-8/metabolismo , RNA/metabolismo , Software
13.
J Nanobiotechnology ; 20(1): 524, 2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36496411

RESUMO

BACKGROUND: Excessive extracellular matrix (ECM) deposition in pancreatic ductal adenocarcinoma (PDAC) severely limits therapeutic drug penetration into tumors and is associated with poor prognosis. Collagen is the most abundant matrix protein in the tumor ECM, which is the main obstacle that severely hinders the diffusion of chemotherapeutic drugs or nanomedicines. METHODS: We designed a collagenase-functionalized biomimetic drug-loaded Au nanoplatform that combined ECM degradation, active targeting, immune evasion, near-infrared (NIR) light-triggered drug release, and synergistic antitumor therapy and diagnosis into one nanoplatform. PDAC tumor cell membranes were extracted and coated onto doxorubicin (Dox)-loaded Au nanocages, and then collagenase was added to functionalize the cell membrane through lipid insertion. We evaluated the physicochemical properties, in vitro and in vivo targeting, penetration and therapeutic efficacy of the nanoplatform. RESULTS: Upon intravenous injection, this nanoplatform efficiently targeted the tumor through the homologous targeting properties of the coated cell membrane. During penetration into the tumor tissue, the dense ECM in the PDAC tissues was gradually degraded by collagenase, leading to a looser ECM structure and deep penetration within the tumor parenchyma. Under NIR irradiation, both photothermal and photodynamic effects were produced and the encapsulated chemotherapeutic drugs were released effectively, exerting a strong synergistic antitumor effect. Moreover, this nanoplatform has X-ray attenuation properties that could serve to guide and monitor treatment by CT imaging. CONCLUSION: This work presented a unique and facile yet effective strategy to modulate ECM components in PDAC, enhance tumor penetration and tumor-killing effects and provide therapeutic guidance and monitoring.


Assuntos
Nanopartículas , Neoplasias Pancreáticas , Fotoquimioterapia , Humanos , Nanopartículas/química , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Neoplasias Pancreáticas/tratamento farmacológico , Matriz Extracelular , Linhagem Celular Tumoral , Fototerapia/métodos
14.
J Nanobiotechnology ; 20(1): 351, 2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35907841

RESUMO

BACKGROUND: The efficacy of immune checkpoint blockade (ICB), in the treatment of hepatocellular carcinoma (HCC), is limited due to low levels of tumor-infiltrating T lymphocytes and deficient checkpoint blockade in this immunologically "cool" tumor. Thus, combination approaches are needed to increase the response rates of ICB and induce synergistic antitumor immunity. METHODS: Herein, we designed a pH-sensitive multifunctional nanoplatform based on layered double hydroxides (LDHs) loaded with siRNA to block the intracellular immune checkpoint NR2F6, together with the asynchronous blockade surface receptor PD-L1 to induce strong synergistic antitumor immunity. Moreover, photothermal therapy (PTT) generated by LDHs after laser irradiation modified an immunologically "cold" microenvironment to potentiate Nr2f6-siRNA and anti-PD-L1 immunotherapy. Flow cytometry was performed to assess the immune responses initiated by the multifunctional nanoplatform. RESULTS: Under the slightly acidic tumor extracellular environment, PEG detached and the re-exposed positively charged LDHs enhanced tumor accumulation and cell uptake. The accumulated siRNA suppressed the signal of dual protumor activity in both immune and H22 tumor cells by silencing the NR2F6 gene, which further reduced the tumor burden and enhanced systemic antitumor immunity. The responses include enhanced tumor infiltration by CD4+ helper T cells, CD8+ cytotoxic T cells, and mature dendritic cells; the significantly decreased level of immune suppressed regulator T cells. The therapeutic responses were also attributed to the production of IL-2, IFN-γ, and TNF-α. The prepared nanoparticles also exhibited potential magnetic resonance imaging (MRI) ability, which could serve to guide synergistic immunotherapy treatment. CONCLUSIONS: In summary, the three combinations of PTT, NR2F6 gene ablation and anti-PD-L1 can promote a synergistic immune response to inhibit the progression of primary HCC tumors and prevent metastasis. This study can be considered a proof-of-concept for the targeting of surface and intracellular immune checkpoints to supplement the existing HCC immunotherapy treatments.


Assuntos
Antígeno B7-H1/metabolismo , Carcinoma Hepatocelular , Neoplasias Hepáticas , Antígeno B7-H1/antagonistas & inibidores , Carcinoma Hepatocelular/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Hidróxidos/uso terapêutico , Imunoterapia/métodos , Neoplasias Hepáticas/tratamento farmacológico , Terapia Fototérmica , RNA Interferente Pequeno/uso terapêutico , Proteínas Repressoras/uso terapêutico , Microambiente Tumoral
15.
Plant Dis ; 2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-36572971

RESUMO

Tea plants (Camellia sinensis L.) are an important cash crop and are cultivated worldwide for their commercial value (Palanisamy et al. 2014). Tea gray blight is an important tea plant disease as it can cause a decline in tea quality and reduce yields by 20-30% (Sanjay et al. 2008). In August 2018, a disease survey was conducted on 400 ha of organic tea plantations in the Pu'er area of Yunnan Province (22.48° N, 100.58° E). The survey found that widespread disease was causing damage to 40% of the tea plantations and that the most seriously affected tea variety was Yunkang No. 10, which had an average disease incidence of 30-35%. The affected leaves grew small yellow-green spots on their tips or margins in the early stage that expanded into round or irregular brown spots with distinct concentric whorls and black conidial disks arranged in whorls when the humidity was high (Fig. 1A-B), which is consistent with tea gray blight disease (Zheng et al. 2021). Twenty-four diseased leaf samples were collected from four different tea plantations and transported to the Pu-Erh Tea Research Laboratory. Leaves with disease spots were cut into 4 mm ×4 mm square pieces, surface-sterilized with 75% alcohol for 1 min, disinfected with 1% sodium hypochlorite for 3 min, and washed thrice with sterile water. The tissue pieces were placed on potato dextrose agar (PDA) plates containing 100 µg ml-1 of chloramphenicol (Wang et al. 2021). After 3 d of culturing in the dark at 28 C, twenty pure cultures with similar morphology were obtained, and two representative isolates were selected and transferred into new PDA media. After 7 d, circular fungal colonies with dense aerial mycelium produced black, wet spore masses that grew on the PDA media (Fig. 1C-D). The conidia were spindle-shaped with four septa, measuring 25.0 (21.0-26.0) × 6.0 (4.5-7.0) µm (n=15). The conidia had three median cells, two of which were dark brown in color with unclear separations, with a single basal hyaline appendage 3.8 (3.5-4.5) µm (n=30) in length and 2-3 apical hyaline appendages 31 (27-35) µm in length (n=30) (Fig. 1E), similar to the conidial characteristics of Neopestalotiopsis piceana (Maharachchikumbura et al. 2014). Two isolates were selected for DNA extraction. The internal transcribed spacer (ITS) region, partial translation elongation factor 1-alpha (tef1-α) gene, and partial ß-tubulin (tub2) gene were amplified using the ITS1F-ITS4 primer set (White et al 1990), the EF-1α-F and EF-1α-R primer sets (Li et al. 2018), and the tub1 and tub2 primers, respectively (Chauhan et al. 2007). The ITS (OP535632 to OP535632), tef1-α (OP589285,OP589287), and tub2 (OP589286,OP589288) sequences were submitted to NCBI GenBank. Basic Local Alignment Search Tool analysis demonstrated that these sequences were 100% similar to those of N. piceana isolates available in GenBank. The sequences were compared using the Mafft software package, and sequences with the same ID were concatenated using scripts. A maximum likelihood phylogenetic tree was constructed using the MEGA (ver. 5.1) software package based on the concatenated sequences (ITS, tef1-α, and tub2). Phylogenetic analysis revealed that C-5 and B-3 showed 95% bootstrap support with N. piceana isolates in references (Fig. 2). According to the morphology and molecular characterization, C-5 and B-3 were identified as N. piceana. Pathogenicity tests on these two isolates were conducted using 36 healthy tea plants. The leaves were scratched slightly with sterile toothpick tips, after which pathogen cakes (6 mm diameter) were placed on the wounds with the mycelial side facing down and covered with sterile absorbent cotton to maintain a moist environment. Control leaves were wounded and covered with sterile PDA plugs (three replicates per treatment, three plants per replicate). Seven days later, the inoculated leaves exhibited similar symptoms observed under natural conditions, whereas the control leaves exhibited no symptoms. The same isolates as the introduced strains were isolated from the diseased tea leaves, completing Koch's postulates. To our knowledge, this is the first report of N. piceana causing gray blight on tea leaves in China. These results provide valuable information for the prevention and management of gray blight on tea leaves. References: Chauhan, J. B., et al. 2007. Indian J Biotechnol. 6: 404-406 Li, D. X., et al. 2018. J. Trop. Crops. 39:1827-1833. Maharachchikumbura, S. N., et al. 2014. Stud. Mycol. 79:121-186. Palanisamy, S., et al. 2014. Appl. Biochem. Biotechnol. 172:216-223. Sanjay, R., et al. 2008. Crop Protect. 27(3-5): 689-694. Wang, Q. M., et al. 2021. Front. Microbiol. 12:774438. White, T. J., et al. 1990. Academic, San Diego. 315-322 Zheng, S., et al. 2021. Plant Dis. 105:3723-3726.

16.
Molecules ; 27(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36500299

RESUMO

The decomposition of ammonia borane (NH3BH3) to produce hydrogen has developed a promising technology to alleviate the energy crisis. In this paper, metal and non-metal diatom-doped CoP as catalyst was applied to study hydrogen evolution from NH3BH3 by density functional theory (DFT) calculations. Herein, five catalysts were investigated in detail: pristine CoP, Ni- and N-doped CoP (CoPNi-N), Ga- and N-doped CoP (CoPGa-N), Ni- and S-doped CoP (CoPNi-S), and Zn- and S-doped CoP (CoPZn-S). Firstly, the stable adsorption structure and adsorption energy of NH3BH3 on each catalytic slab were obtained. Additionally, the charge density differences (CDD) between NH3BH3 and the five different catalysts were calculated, which revealed the interaction between the NH3BH3 and the catalytic slab. Then, four different reaction pathways were designed for the five catalysts to discuss the catalytic mechanism of hydrogen evolution. By calculating the activation energies of the control steps of the four reaction pathways, the optimal reaction pathways of each catalyst were found. For the five catalysts, the optimal reaction pathways and activation energies are different from each other. Compared with undoped CoP, it can be seen that CoPGa-N, CoPNi-S, and CoPZn-S can better contribute hydrogen evolution from NH3BH3. Finally, the band structures and density of states of the five catalysts were obtained, which manifests that CoPGa-N, CoPNi-S, and CoPZn-S have high-achieving catalytic activity and further verifies our conclusions. These results can provide theoretical references for the future study of highly active CoP catalytic materials.


Assuntos
Boranos , Diatomáceas , Amônia , Metais , Hidrogênio , Modelos Teóricos
17.
Yi Chuan ; 44(5): 362-369, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35729694

RESUMO

Recent success in the retrieval of nuclear DNA of ancient humans and animals from cave sediments paves the way for genome-wide studies of past populations directly from sediments. In three studies, nuclear genomes of different species were obtained from the sediments of multiple archeological caves and their genetic histories were revealed, including an unknown population replacement of Neanderthals from Estatuas cave in Spain, which was recovered using a new DNA capture approach. By extending sediments as a source of DNA beyond fossils, this breakthrough is of particular significance to the field of ancient human genomics, which brings about more possibilities for exploring the history of past population migration, evolution and adaptation within larger time-scales and geographical areas where no fossil remains exist. Here, we mainly review the significance of the technical advances in retrieving ancient nuclear DNA from sediments and present new insights into the genetic history of Neanderthals revealed by this technique. By combining ancient genomes retrieved from fossils and additional mitochondrial DNA extracted from sediments of archaeological sites, we may begin investigating diverse archaic populations and examine their genetic relationships, movements and replacements in detail.


Assuntos
Hominidae , Homem de Neandertal , Animais , DNA Antigo , DNA Mitocondrial/genética , Genoma Humano , Hominidae/genética , Humanos , Homem de Neandertal/genética
18.
Yi Chuan ; 44(5): 414-423, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35729698

RESUMO

Fermentation production is the most primitive application of microorganisms by humans, which is of great significance in human history. However, due to the lack of molecular evidence, the history of human fermentation production and the evolution and domestication of fermentation microorganisms remain to be further investigated. Taking wine and fermented dairy, the two most common types of fermented foods as examples, we introduce the archaeology evidence of fermented foods and the evolution and domestication of fermented microorganisms, introduce the research status of paleomicrobiology and fermented paleomicroorganisms, and explore the feasibility and challenges of the research of ancient fermented microorganisms applying microbial ancient DNA technology, as well as the application potential of ancient DNA capture technology in this field.


Assuntos
DNA Antigo , Alimentos Fermentados , Domesticação , Fermentação , Humanos , Tecnologia
19.
RNA ; 25(7): 768-782, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31004009

RESUMO

RNA-binding proteins (RBPs) and miRNAs are critical gene expression regulators that interact with one another in cooperative and antagonistic fashions. We identified Musashi1 (Msi1) and miR-137 as regulators of a molecular switch between self-renewal and differentiation. Msi1 and miR-137 have opposite expression patterns and functions, and Msi1 is repressed by miR-137. Msi1 is a stem-cell protein implicated in self-renewal while miR-137 functions as a proneuronal differentiation miRNA. In gliomas, miR-137 functions as a tumor suppressor while Msi1 is a prooncogenic factor. We suggest that the balance between Msi1 and miR-137 is a key determinant in cell fate decisions and disruption of this balance could contribute to neurodegenerative diseases and glioma development. Genomic analyses revealed that Msi1 and miR-137 share 141 target genes associated with differentiation, development, and morphogenesis. Initial results pointed out that these two regulators have an opposite impact on the expression of their target genes. Therefore, we propose an antagonistic model in which this network of shared targets could be either repressed by miR-137 or activated by Msi1, leading to different outcomes (self-renewal, proliferation, tumorigenesis).


Assuntos
Diferenciação Celular , Transformação Celular Neoplásica/patologia , Regulação Neoplásica da Expressão Gênica , Glioblastoma/patologia , MicroRNAs/genética , Proteínas do Tecido Nervoso/metabolismo , Neurogênese , Proteínas de Ligação a RNA/metabolismo , Animais , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Proteínas do Tecido Nervoso/genética , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Células Tumorais Cultivadas
20.
Photosynth Res ; 149(1-2): 57-68, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32783175

RESUMO

Plants in their natural environment are often exposed to fluctuating light because of self-shading and cloud movements. As changing frequency is a key characteristic of fluctuating light, we speculated that rapid light fluctuation may induce rapid photosynthetic responses, which may protect leaves against photoinhibition. To test this hypothesis, maize seedlings were grown under fluctuating light with various frequencies (1, 10, and 100 cycles of fluctuations/10 h), and changes in growth, chlorophyll content, gas exchange, chlorophyll a fluorescence, and P700 were analyzed carefully. Our data show that though the growth and light-saturated photosynthetic rate were depressed by rapidly fluctuating light, photosynthesis induction was clearly speeded up. Furthermore, more rapid fluctuation of light strikingly reduced the chlorophyll content, while thermal dissipation was triggered and enhanced. The chlorophyll a fluorescence induction kinetics and P700 absorption results showed that the activities of both photosystem II and photosystem I decreased as the frequency of the fluctuating light increased. In all treatments, the light intensities of the fluctuating light were kept constant. Therefore, rapid light fluctuation frequency itself induced the acceleration of photosynthetic induction and the enhancement of photoprotection in maize seedlings, which play important roles in protecting photosynthetic apparatus against fluctuating high light to a certain extent.


Assuntos
Adaptação Ocular/fisiologia , Adaptação Fisiológica , Fotossíntese/fisiologia , Folhas de Planta/metabolismo , Luz Solar/efeitos adversos , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Estresse Fisiológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA