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BACKGROUND: The impact of acrylamide (ACR) on learning and memory has garnered considerable attention. However, the targets and mechanisms are still unclear. RESULTS: Elongation factor 2 (eEF2) was significantly upregulated in the results of serum proteomics. Results from in vitro and in vivo experiments indicated a notable upregulation of Eukaryotic elongation factor 2 kinase (eEF2K), the sole kinase responsible for eEF2 phosphorylation, following exposure to ACR (P < 0.05). Subsequent in vitro experiments using eEF2K siRNA and in vivo experiments with eEF2K-knockout mice demonstrated significant improvements in abnormal indicators related to ACR-induced learning and memory deficits (P < 0.05). Proteomic analysis of the hippocampus revealed Lpcat1 as a crucial downstream protein regulated by eEF2K. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated that eEF2K may play a role in the process of ACR-induced learning and memory impairment by affecting ether lipid metabolism. CONCLUSIONS: In summary, eEF2K as a pivotal treatment target in the mechanisms underlying ACR-induced learning and memory impairment, and studies have shown that it provides robust evidence for potential clinical interventions targeting ACR-induced impairments.
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BACKGROUND: Tuberculosis (TB) is not only related to infection but also involves immune factors. This study explores the changes in T-lymphocyte subsets in children with TB who are human immunodeficiency virus (HIV)-negative and examines their relationship using chest computed tomography (CT) scans. Additionally, the study identifies risk factors for severe TB (STB) in children and establishes relevant risk prediction models. METHODS: We recruited 235 participants between 2018 and 2022, comprising 176 paediatric patients with TB who were HIV-negative and 59 age-matched children with bacterial community-acquired pneumonia (CAP). We quantitatively analysed and compared T-lymphocyte subsets between the two groups and among different types of TB infection. Both univariate and multivariate analyses of clinical and laboratory characteristics were conducted to identify independent risk factors for STB in children and to establish a risk prediction model. RESULTS: The absolute counts of CD3, CD4 and CD8 T-cells in children with TB infection decreased significantly compared with bacterial CAP. The percentage of CD8 T-cells increased, whereas the percentage of CD4 T-cells did not change significantly. The absolute count of CD3, CD4 and CD8 T-cells in extrapulmonary TB (EPTB) was significantly higher than in extra-respiratory TB, with unchanged subset percentages. According to chest CT lesion classification, CD4 T-cell counts decreased significantly in S3 compared with S1 or S2, with no significant change in CD3 and CD8 T-cell counts and percentages. No significant differences were observed in lymphocyte subset counts and percentages between S1 and S2. Univariate analyses indicated that factors such as age, symptom duration, white blood cell count, platelet count, neutrophil-to-lymphocyte ratio (NLR), erythrocyte sedimentation rate, prealbumin level, albumin level, globulin level, albumin/globulin (A/G) ratio, high-sensitivity C-reactive protein (Hs-CRP) level and CD4 and CD8 T-cell counts are associated with STB. Multivariate logistic regression analysis revealed that age, Hs-CRP level, NLR, symptom duration and A/G ratio are independent risk factors for STB in children. Increased age, Hs-CRP levels and NLR, along with decreased A/G, correlate with increased susceptibility to STB. A nomogram model, based on these independent risk factors, demonstrated an area under the receiver operating characteristics curve of 0.867 (95% CI: 0.813-0.921). Internal verification confirmed the model's accuracy, with the calibration curve approaching the ideal and the Hosmer-Lemeshow goodness-of-fit test showing consistent results (χ2 = 12.212, p = 0.142). CONCLUSION: In paediatric patients with TB, the absolute counts of all lymphocyte subsets were considerably reduced compared with those in patients with bacterial CAP. Clinicians should consider the possibility of EPTB infection in addition to respiratory infections in children with TB who have higher CD3, CD4 and CD8 T-cell counts than the ERTB group. Furthermore, CD4 T-cell counts correlated closely with the severity of chest CT lesions. Age, symptom duration, A/G ratio, Hs-CRP level and NLR were established as independent risk factors for STB. The nomogram model, based on these factors, offers effective discrimination and calibration in predicting STB in children.
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Globulinas , Infecciones por VIH , Tuberculosis Latente , Mycobacterium tuberculosis , Tuberculosis , Humanos , Niño , Proteína C-Reactiva , Subgrupos de Linfocitos T , Tuberculosis/diagnóstico , Factores de Riesgo , Subgrupos Linfocitarios , Recuento de LinfocitosRESUMEN
Jingjin (muscle region of meridian) is a distal diagnosis and treatment system of the sinew/fascia disorders on the base of the concept of jin in TCM. Jin should be a particular palpable structure rather than a single anatomic structure with a specific distributing course. Yizhi weishu refers to a idea running through the whole process of diagnosis and treatment of sinew/fascia disorders, in which, the results, obtained by the overall observation and palpation of patient's sinew/fascia structure, are taken as the criteria of treatment. Yitong weishu (taking the sites of sensitivity or tenderness as the points) verifies this idea in practice. Under the guidance of yizhi weishu, through identifying the primary from the secondary, and regulating yin and yang, the spasticity and flaccidity of sinews/fascia can be cured and the induced diseases treated. The diagnosis and treatment system of jingjin, based on yizhi weishu, develops the original jingjin theory with vague concept involved, formulates a systematic thinking of treatment for sinew/fascia disorders and provides a new approach to clinical treatment.
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Terapia por Acupuntura , Meridianos , Humanos , Espasticidad MuscularRESUMEN
We report a copper-catalyzed ligand-controlled selective 1,2- and 1,4-hydrosilylation of 1,3-enynes, which furnishes enantiomerically enriched propargyl- and 1,2-allenylsilane products in high yields with excellent enantioselectivities (up to 99% ee). This reaction proceeds under mild conditions, shows broad substrate scope for both 1,3-enynes and trihydrosilanes, and displays excellent regioselectivities. Mechanistic studies based on deuterium-labeling reactions and density functional theory (DFT) calculations suggest that allenylcopper is the dominant reactive intermediate under both 1,2- and 1,4-hydrosilylation conditions, and it undergoes metathesis with silanes via selective four-membered or six-membered transition state, depending on the nature of the ligand. The weak interactions between the ligands and the reacting partners are found to be the key controlling factor for the observed regioselectivity switch. The origin of high enantiocontrol in the 1,4-hydrosilylation is also revealed by high level DLPNO-CCSD(T) calculations.
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Acrylamide is widely found in a variety of fried foods and cigarettes and is not only neurotoxic and carcinogenic, but also has many potential toxic effects. The current assessment of acrylamide intake through dietary questionnaires is confounded by a variety of factors, which poses limitations to safety assessment. In this review, we focus on the levels of AAMA, the urinary metabolite of acrylamide in humans, and its association with other diseases, and discuss the current research gaps in AAMA and the future needs. We reviewed a total of 25 studies from eight countries. In the general population, urinary AAMA levels were higher in smokers than in non-smokers, and higher in children than in adults; the highest levels of AAMA were found in the population from Spain, compared with the general population from other countries. In addition, AAMA is associated with several diseases, especially cardiovascular system diseases. Therefore, AAMA, as a biomarker of internal human exposure, can reflect acrylamide intake in the short term, which is of great significance for tracing acrylamide-containing foods and setting the allowable intake of acrylamide in foods.
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Acetilcisteína , Acrilamida , Adulto , Niño , Humanos , Acrilamida/toxicidad , Biomarcadores/orina , Encuestas y CuestionariosRESUMEN
A copper-catalyzed regioselective Markovnikov 3,4-hydrosilylation of 2-substituted 1,3-dienes has been accomplished. A wide range of 2-substituted 1,3-dienes and trihydrosilanes are compatible under the optimal conditions. The bisphosphine ligand with a rigid backbone provides the Markovnikov 3,4-hydrosilylation product in better yield and selectivity. Besides, the synthetic utilities of the allylsilanes also were demonstrated by their flexible derivatizations.
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Cobre , Polienos , CatálisisRESUMEN
Sphingosine kinase 1 (SphK1) is an important signaling molecule for cell proliferation and survival. However, the role of SphK1 in acrylamide (ACR)-induced nerve injury remains unclear. The purpose of this study was to investigate the role and potential mechanism of SphK1 in ACR-induced nerve injury. Liquid chromatography triple quadrupole tandem mass spectrometry (LC-MS/MS) and reverse transcription-quantitative PCR (RT-qPCR) were used to detect sphingosine 1-phosphate (S1P) content in serum and SphK1 content in whole blood from an occupational work group exposed to ACR compared to a non-exposed group. For in vitro experiments, SphK1 in human SH-SY5Y neuroblastoma cells was activated using SphK1-specific activator phorbol 12-myristate 13-acetate (PMA). Our research also utilized cell viability assays, flow cytometry, western blots, RT-qPCR and related protein detection to assess activity of the mitogen activated protein kinase (MAPK) signaling pathway. The results of the population study showed that the contents of SphK1 and S1P in the ACR-exposed occupational contact group were lower than in the non-exposed group. The results of in vitro experiments showed that expression of SphK1 decreased with the increase in ACR concentration. Activating SphK1 improved the survival rate of SH-SY5Y cells and decreased the apoptosis rate. Activating SphK1 in SH-SY5Y cells also regulated MAPK signaling, including enhancing the phosphorylation of extracellular signal-regulated protein kinases (ERK) and inhibiting the phosphorylation of c-Jun N-terminal kinase (JNK) and p38. These results suggest that activating SphK1 can protect against nerve cell damage caused by ACR.
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Acrilamida , Espectrometría de Masas en Tándem , Acrilamida/toxicidad , Cromatografía Liquida , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Humanos , Neuronas/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)RESUMEN
BACKGROUND: Antiphospholipid syndrome (APS) is an autoimmune disease that is associated with recurrent pregnancy loss. It is still controversial whether the presence of antiphospholipid antibodies (aPL) in the serum of patients with in vitro fertilization-embryo transfer (IVF-ET) has a negative effect on the outcomes. In view of the discrepancies, a meta-analysis of the published data was performed to explore the relationship of aPL and IVF-ET outcomes. METHODS: We searched for all published articles indexed in PubMed, Web of Science, and Cochrane Library, which were retrieved up to April, 2021. A total of 921 studies were yielded, of which 6 finally met the inclusion criteria. We carried out the meta-analysis by pooling results of these studies with Review Manager 5.3 software. The effect index was measured with 95% confidence intervals (CIs) of the relative risks (RRs). RESULTS: Six eligible studies were included in this meta-analysis, involving 3214 patients. Our results showed that positive aPL was not associated with decreased clinical pregnancy rate (RR 0.97; 95% CI 0.91-1.04). There was no correlation between positive aPL and increased miscarriage risk (RR 1.22; 95% CI 0.94-1.58). Only 5 of the 6 studies referred to live birth rate, but still no association was found between them (RR 0.95; 95% CI 0.81-1.11). CONCLUSIONS: The results showed that the presence of positive aPL neither decreased clinical pregnancy rate and live birth rate, nor increased miscarriage rate in women undergoing IVF, which is differed from the opinion of clinical practice. More prospective studies with high quality and larger sample size are needed to evaluate the relationship between positive aPL and outcomes of IVF-ET.
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Aborto Habitual , Resultado del Embarazo , Anticuerpos Antifosfolípidos , Femenino , Fertilización In Vitro/métodos , Humanos , Nacimiento Vivo , Embarazo , Resultado del Embarazo/epidemiología , Índice de Embarazo , Estudios ProspectivosRESUMEN
A copper-catalyzed regiodivergent hydrosilylation of a wide range of simple allenes is reported. Linear and branched allylsilanes were formed by judicious choice of solvents. Furthermore, branched allylsilanes were obtained with high enantioselectivity (up to 97% enantiomeric excess) with the aid of a C2-symmetric bisphosphine ligand in the unprecedented asymmetric allene hydrosilylation.
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Alcadienos , Cobre , Catálisis , EstereoisomerismoRESUMEN
A convenient method for the dienylation of N-benzoylhydrazones in water has been developed. This protocol expanded the synthetic application of functionalized homoallenylboronates to provide the useful 2-aminomethyl-1,3-diene derivatives with high efficiency (up to 99% yield) and stereoselectivity without using any catalyst, additive or inert atmosphere. Furthermore, the transformation of a 2-aminomethyl-1,3-diene derivative to synthesize a functionalized pyrrolidine derivative was also explored.
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Agua , CatálisisRESUMEN
Natural processes and human activities exert important impacts on elemental cycling in coastal sediments, which has not been well documented. Sediments in the Bohai Sea and North Yellow Sea were investigated to assess the impacts of the Yellow River inputs and/or anthropogenic perturbations on diagenesis of iron and sulfur. Labile iron (0.5 M HCl-extractable iron) in the sediments is low due to iron-poor nature of source materials. Dynamic regimes and low availability of labile organic carbon (OC) result in relatively low sulfide contents in deltaic sediments. However, low but continuous supply of labile OC exported from an anthropogenically impacted bay could substantially elevate sulfide burial in sediments near the bay. Neither offshore oil exploitations nor frequent algal blooms in the seas have detectable influences on iron and sulfur diagenesis in the sediments. The sediments are capable of quickly consuming porewater sulfide by reaction with reactive iron under the current conditions.
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Sedimentos Geológicos , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Humanos , Hierro/análisis , Océanos y Mares , Azufre/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Ultraviolet B (UVB) is one of the most common exogenous factors in skin aging, especially photoaging. Once a large amount of UVB accumulates within a short period of time, skin tissue can become inflamed. It has also been found in clinics that platelet-rich plasma (PRP) can promote wound repair; therefore, the aim of this study was to identify the mechanism by which PRP repairs UVB-induced skin photodamage. We used PRP of Sprague-Dawley rats with the two-spin technique in the established acute UVB radiation photodamage model and harvested the corresponding skin after 1, 7, and 28 d. Hematoxylin and eosin staining was used to observe tissue inflammation. We found that PRP reduces inflammation in the early stages of UVB-induced acute skin damage, and then promotes the proliferation of collagen in the middle and late stages. Moreover, PRP can stimulate Act A and M1 polarization in the early stage, while inhibiting activin A (Act A) and inducing M2 polarization in the middle and late stages. In conclusion, this study demonstrates that PRP plays an important regulatory role in helping reduce UVB-induced acute skin tissue inflammation by adjusting macrophage polarization, which alleviates skin inflammation and stimulates collagen regeneration.
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Receptores de Activinas/metabolismo , Folistatina/metabolismo , Inflamación/metabolismo , Plasma Rico en Plaquetas/metabolismo , Envejecimiento de la Piel , Animales , Modelos Animales de Enfermedad , Femenino , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/efectos de la radiación , Ratas , Ratas Sprague-Dawley , Piel/patología , Rayos UltravioletaRESUMEN
This research aimed to investigate the allergic reaction of C3H/HeJ mice after sensitization with ovalbumin (OVA) without any adjuvant and to analyze the association between intestinal microbiota and allergy-related immune cells in mesenteric lymph nodes (MLN). The allergic responses of C3H/HeJ mice orally sensitized with OVA were evaluated, and immune cell subsets in spleen and MLN and cytokines were also detected. The intestinal bacterial community structure was analyzed, followed by Spearman correlation analysis between changed gut microbiota species and allergic parameters. Sensitization induced a noticeable allergic response to the gavage of OVA without adjuvant. Increased levels of Th2, IL-4, CD103+CD86+ DC, and MHCII+CD86+ DC and decreased levels of Th1, Treg, IFN-γ, TGF-ß1, and CD11C+CD103+ DC were observed in allergic mice. Furthermore, families of Lachnospiraceae, Clostridiaceae_1, Ruminococcaceae, and peprostreptococcaceae, all of which belonging to the order Clostridiales, were positively related to Treg and CD11C+CD103+ DC, while they were negatively related to an allergic reaction, levels of Th2, CD103+CD86+ DC, and MHCII+CD86+ DC in MLN. The family of norank_o_Mollicutes_RF39 belonging to the order Mollicutes_RF39 was similarly correlated with allergic reaction and immune cells in MLN of mice. To sum up, allergic reactions and intestinal flora disturbances could be induced by OVA oral administration alone. The orders of Clostridiales and Mollicutes_RF39 in intestinal flora are positively correlated with levels of Treg and CD11C+CD103+ DC in MLN of mice.
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Células Dendríticas/inmunología , Hipersensibilidad a los Alimentos/microbiología , Microbioma Gastrointestinal , Ganglios Linfáticos/inmunología , Linfocitos T Reguladores/inmunología , Animales , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Citocinas/inmunología , Modelos Animales de Enfermedad , Heces/microbiología , Hipersensibilidad a los Alimentos/inmunología , Mesenterio , Ratones , Ratones Endogámicos C3H , Ovalbúmina/inmunología , Bazo/inmunologíaRESUMEN
OBJECTIVES: The aim of this study was to explore the correlation between blood profiles and cognitive functions or mild cognitive impairment (MCI) in the Chinese population aged 35-64 years old. METHODS: A cross-sectional study was performed, which recruited 675 Chinese adults aged 35-64 years old from Beijing, China. Their cognitive performance was assessed with Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA), the serum lipids levels were measured by hexokinase method and colorimetric assay, and the plasma fatty acids profiles were analyzed by fast gas chromatography. RESULTS: Among the 675 participants, 84 (12.4%) had MCI. Age, years of education, saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were associated with MMSE scores (all P < 0.05). Age, years of education, smoking, drinking, non-esterified fatty acids (NEFAs), SFAs, MUFAs, n-3 polyunsaturated fatty acids (n-3 PUFAs) and n-6/n-3 PUFAs were associated with MoCA scores (all P < 0.05). Increased age (P = 0.002) and smoking (P = 0.028) were positively associated with the prevalence of MCI, while educational level (P = 0.005) and alcohol drinking (P = 0.003) both were negatively correlated to the prevalence of MCI. Elevated serum NEFAs (P = 0.032), high plasma SFAs (P = 0.023), and excessive polyunsaturated fatty acids (PUFAs) levels (P = 0.033) were significantly associated with increased frequency of MCI. CONCLUSION: In the Chinese population aged 35-64 years, advanced age and cigarette smoking were risk factors of MCI, whereas higher educational level and alcohol drinking were protective factors for MCI. Excessive serum or plasma levels of NEFAs, SFAs and PUFAs were associated with an increased risk of MCI.
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Disfunción Cognitiva/sangre , Ácidos Grasos no Esterificados/sangre , Ácidos Grasos Insaturados/sangre , Ácidos Grasos/sangre , Adulto , Pueblo Asiatico , China , Disfunción Cognitiva/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Pruebas de Estado Mental y Demencia , Persona de Mediana EdadRESUMEN
OBJECTIVE: To explore the protective effect of Peroxiredoxin 4 (PRDX4) on the testes undergoing heat stress in PRDX4 knockout mice. METHODS: Twenty-four C57BL/6 mice underwent CRISPR/Cas9-mediated total knockout of the PRDX4 gene and another 24 wild-type mice were used as controls. At 9 weeks of age, the rats were subjected to 15-minute testicular heat stress in 43â water once a day for 3 days, or in 25â water as the control. Before and at 1 day and 5 weeks after treatment, 4 from each group were sacrificed respectively and their testes harvested for observation of histological changes by HE staining, detection of the apoptosis of spermatogenic cells by TUNEL and determination of the expression of PRDX4 by Western blot and those of the oxidative stress factors hydroxynonenal (HNE) and 8-OHdG by immunohistochemistry. RESULTS: No statistically significant differences were observed in testicular histology, the apoptosis rate of spermatogenic cells, and the expressions of HNE and 8-OHdG between the PRDX4 knockout mice and wild-type controls (P > 0.05). After 1-day 43â heat stress, the PRDX4 knockout mice showed a significantly increased apoptosis rate of spermatogenic cells as compared with the baseline (ï¼»38.65 ± 2.57ï¼½% vs ï¼»0.46 ± 0.06ï¼½%, P < 0.01), and so did the wild-type controls (ï¼»13.21 ± 1.43ï¼½% vs ï¼»0.33 ± 0.01ï¼½%, P < 0.01), higher in the PRDX4 knockout than in the wild-type control group even at 5 weeks after heat stress (ï¼»3.09 ± 0.16ï¼½% vs ï¼»1.45 ± 0.11ï¼½%, P < 0.01). The PRDX4 knockout mice also exhibited a markedly upregulated expression of 8-OHdG (38.25 ± 1.19 vs 19.54 ± 1.13, P < 0.01), and so did the wild-type controls (24.30 ± 1.65 vs 18.22 ± 1.18, P < 0.01), higher in the PRDX4 knockout than in the wild-type control group even at 5 weeks after heat stress (25.40 ± 1.57 vs 23.25 ± 1.48, P < 0.01). The expression of HNE, however, showed no statistically significant difference before and at 1 day after 43â heat stress either in the PRDX4 knockout mice or in the wild-type controls (P > 0.05), though remarkably higher in the former than in the latter group at 5 weeks after treatment (28.57 ± 0.56 vs 19.00 ± 1.35, P < 0.01). The expression of 8-OHdG was also higher in the PRDX4 knockout than in the wild-type control group at 5 weeks, but with no statistically significant difference (P > 0.05). CONCLUSIONS: PRDX4 can effectively protect the testis from heat stress and promote the restoration of its spermatogenic function.
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Respuesta al Choque Térmico , Estrés Oxidativo , Peroxirredoxinas/genética , Testículo , Animales , Apoptosis , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Testículo/metabolismoAsunto(s)
Rosácea , Enfermedades de la Piel , Estudios Transversales , Diagnóstico Diferencial , Humanos , Rosácea/diagnóstico , PielRESUMEN
Lately, Drosophila has been favored as a model in sleep and circadian rhythm research due to its conserved mechanism and easily manageable operation. These studies have revealed the sophisticated parameters in whole-day sleep profiles of Drosophila, drawing connections between Drosophila sleep and human sleep. In this study, we tested several sleep deprivation protocols (mechanical shakes and light interruptions) on Drosophila and delineated their influences on Drosophila sleep. We applied a daytime light-deprivation protocol (DD) mimicking jet-lag to screen drugs that alleviate sleep deprivation. Characteristically, classical sleep-aid compounds exhibited different forms of influence: phenobarbital and pentobarbital modified total sleep time, while melatonin only shortened the latency to sleep. Such results construct the basis for further research on sleep benefits in other treatments in Drosophila. We screened seven herb extracts, and found very diverse results regarding their effect on sleep regulation. For instance, Panax notoginseng and Withania somnifera extracts displayed potent influence on total sleep time, while Melissa officinalis increased the number of sleep episodes. By comparing these treatments, we were able to rank drug potency in different aspects of sleep regulation. Notably, we also confirmed the presence of sleep difficulties in a Drosophila Alzheimer's disease (AD) model with an overexpression of human Abeta, and recognized clear differences between the portfolios of drug screening effects in AD flies and in the control group. Overall, potential drug candidates and receipts for sleep problems can be identified separately for normal and AD Drosophila populations, outlining Drosophila's potential in drug screening tests in other populations if combined with the use of other genetic disease tools.
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Extractos Vegetales/farmacología , Privación de Sueño/tratamiento farmacológico , Trastornos del Sueño-Vigilia/tratamiento farmacológico , Sueño/fisiología , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/genética , Animales , Ritmo Circadiano/efectos de los fármacos , Modelos Animales de Enfermedad , Drosophila melanogaster/efectos de los fármacos , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Regulación de la Expresión Génica/genética , Humanos , Melatonina/farmacología , Mutación , Panax notoginseng/química , Fenobarbital/farmacología , Extractos Vegetales/química , Sueño/efectos de los fármacos , Sueño/genética , Privación de Sueño/genética , Privación de Sueño/fisiopatología , Trastornos del Sueño-Vigilia/genética , Trastornos del Sueño-Vigilia/fisiopatología , Withania/químicaRESUMEN
To be green and sustainable are essential requirements for modern agriculture in China, with fertilizer input being one of the keys. Developing and extending organic fertilizer has become a basic national policy for agricultural production in China for its eco-friendly and advantages in fertile farmland nurture. Organic fertilizer has wide source and variety. The conditions for agricultural production are also largely different. We analyzed the status of organic fertilizer products and stan-dards, physical and chemical properties differences, differences of carbon and nitrogen mineralization characteristics and their influencing factors. Meanwhile, we reviewed the effects of application of organic fertilizer on basic soil fertility of cultivated land. Due to the differences in source and production process, different organic fertilizers differ in the four main internal factors (the content of organic carbon fractions, total N, active nitrogen and C/N) affecting carbon and nitrogen mineralization characteristics, including mineralization rates and the amount of available nitrogen release. With the influence of external conditions such as edatope, different organic fertilizers vary in nutrient supply characteristics. Overall, organic fertilizer significantly increases soil organic matter content, especially for labile organic matter content and carbon management index (CMI). Moreover, soil contents of nitrogen, phosphorus and potassium are expanded. As a result, nutrient loss caused by crop growth is reduced, with positive consequences on soil quality. The application of organic fertilizer on fertile farmland nurture, the theoretical study of organic fertilizer, and the development of safe and efficient organic fertilizer products should be strengthened in the future, promoting the efficient recycling of organic fertilizer resources which could be an important agricultural resource.
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Estiércol , Suelo , Agricultura , China , Fertilizantes , Nitrógeno , NutrientesRESUMEN
The Cu-catalyzed 1,4-protosilylation and protoborylation of trifluoromethyl-substituted conjugated enynes were developed to access functionalized homoallenylsilanes and homoallenylboronates. This protocol also provides a general method to synthesize optically active homoallenylsilanes and homoallenylboronates in moderate to excellent yields with high enantiomeric excess by using new designed chiral bisoxazoline ligands. Simultaneously, the transformations of homoallenylsilanes and homoallenylboronates were also explored to synthesize useful building blocks.
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A novel method of metal-free dehydrogenative silylation of enamides has been developed. The desired functionalized vinylsilane products were obtained in moderate to good yield and with high stereoselectivities. This protocol displays good tolerance of various functionalities. Furthermore, the high chemoselectivity of this reaction enables us to introduce different unsaturated C-C moieties to the products. The ease of further derivatization of the products to other useful compounds also demonstrates the highly synthetic utility of the current methodology.