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1.
Int J Biol Macromol ; 260(Pt 1): 129476, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38232878

RESUMO

The inherent limitations of Cornstarch (CS) and Carboxymethyl Cellulose (CMC) membranes, such as brittleness, fragility, and water solubility, limit their use in controlled-release fertilizers. This study reports on the synthesis of crosslinked CMC/CS-20-E composite membranes using the casting technique, with epichlorohydrin (ECH) as the crosslinking agent in an acidic environment to crosslink CS and CMC. The synthesized composite film demonstrates remarkable water resistance, as evidenced by the insignificant alteration in its morphology and structure post 72 h of water immersion. Its flexibility is reflected in its capacity to endure knotting and bending, with an elongation at break reaching 78.1 %. Moreover, the degradation rate surpasses 90 % within a span of seven days. The CMC/CS-20-E-x-urea controlled-release fertilizer was subsequently produced using a layer-by-layer self-assembly technique, where urea particles were incorporated into the crosslinked composite solution. This CMC/CS-20-E-x-urea controlled-release fertilizer displayed superior controlled-release performance over a duration of seven days when juxtaposed with pure urea. In particular, the CMC/CS-20-E-3 %-urea controlled-release fertilizer showed a cumulative release rate of 84 % by the seventh day. The controlled-release fertilizers developed in this study offer a promising strategy for creating eco-friendly options that are crucial for fertilizing crops with short growth cycles.


Assuntos
Carboximetilcelulose Sódica , Fertilizantes , Fertilizantes/análise , Carboximetilcelulose Sódica/química , Zea mays , Preparações de Ação Retardada , Amido/química , Água/química , Ureia/química
2.
Acta Trop ; 249: 107057, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37913972

RESUMO

Cryptosporidium parvum could regulate the expression of microRNAs of epithelial cells to facilitate its intracellular propagation. MiR-4521 has been reported to play an important role during the development and progression of tumors and infectious diseases by regulating cell proliferation, apoptosis, and autophagy. However, the implication of miR-4521 during C. parvum infection was still unknown. In this study, the expression of miR-4521 was found to be upregulated in HCT-8 cells infected with C. parvum from 8 h post-infection (pi) to 48 hpi, and its upregulation would be related with the TLR/NF-κB signal pathway during C. parvum infection. One potential target of miR-4521, foxm1, was down-regulated in HCT-8 cells from 24 hpi to 48 hpi, and the expression of foxm1 was negatively regulated by miR-4521. The target relationship between miR-4521 and foxm1 was further validated by using dual luciferase reporter assay. Further studies showed that miR-4521 promoted the propagation of C. parvum in HCT-8 cells through targeting foxm1 by regulating BCL2-mediating cell apoptosis. These results contribute to further understanding of the regulatory mechanisms of host miRNAs during Cryptosporidium infection.


Assuntos
Apoptose , Criptosporidiose , Cryptosporidium parvum , Proteína Forkhead Box M1 , MicroRNAs , Humanos , Apoptose/genética , Criptosporidiose/genética , Criptosporidiose/patologia , Cryptosporidium parvum/genética , MicroRNAs/genética , Proteína Forkhead Box M1/genética
3.
Acta Trop ; 243: 106927, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37080266

RESUMO

Cryptosporidium spp. are protozoan parasites that mainly inhabit intestinal epithelial cells, causing diarrheal diseases in humans and a great number of animals. Cryptosporidium parvum is the most common zoonotic species, responsible for nearly 45% of human cryptosporidiosis worldwide. Understanding the interaction mechanisms between C. parvum and host gastrointestinal epithelial cells has significant implications to control cryptosporidiosis. One up-regulated circRNA ciRS-7 was found previously by our group to promote in vitro propagation of C. parvum in HCT-8 cells. In the present study, miR-135a-5p, was found to be a miRNA target of ciRS-7. Cryptosporidium parvum infection induced significantly down-regulation of miR-135a-5p and dramatic up-regulation of its potential target stat1 gene at mRNA and protein levels. Dual luciferase reporter assays validated the physical interactions between miR-135a-5p and stat1, and between ciRS-7 and miR-135a-5p. Further study revealed that ciRS-7 could sponge miR-135a-5p to positively regulate the protein levels of STAT1 and phosphorylated STAT1 (p-STAT1) and thus promote C. parvum propagation in HCT-8 cells. Our findings further reveal the mystery of regulatory roles of host circRNAs during Cryptosporidium infection, and provide a novel insight to develop strategies to control cryptosporidiosis.


Assuntos
Criptosporidiose , Cryptosporidium parvum , Cryptosporidium , MicroRNAs , Animais , Humanos , Linhagem Celular Tumoral , Criptosporidiose/genética , Cryptosporidium/genética , Cryptosporidium parvum/genética , MicroRNAs/genética , RNA Circular/genética , Fator de Transcrição STAT1/genética , Fator de Transcrição STAT1/metabolismo
4.
Nanoscale ; 15(12): 5579-5597, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36883434

RESUMO

With the rapid growth of 5G communication technology, it is imperative to produce electromagnetic interference (EMI) shielding materials to combat the growing electromagnetic radiation pollution. For new shielding applications, EMI shielding materials with high flexibility, light weight and good mechanical strength are in high demand. Due to their light weight, high flexibility, excellent EMI shielding performance, high mechanical properties, and multifunctionality, Ti3C2Tx MXene nanocomposite films have shown absolute benefits in EMI shielding in recent years. Consequently, numerous lightweight and flexible high-performance Ti3C2Tx MXene nanocomposite films have been generated quickly. In this article, we discuss not only the present state of EMI shielding material research, but also the synthesis and electromagnetic properties of Ti3C2Tx MXene. In addition, the loss mechanism of EMI shielding is described, with an emphasis on the analysis and summary of the research progress of diverse layer structured Ti3C2Tx MXene nanocomposite films for EMI shielding. Finally, the current issues of design and fabrication for Ti3C2Tx MXene nanocomposite films that need to be addressed are proposed, as well as the future research direction for Ti3C2Tx MXene nanocomposite films.

5.
ACS Omega ; 6(50): 35039-35049, 2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-34963985

RESUMO

The hydrogel prepared by graft copolymerization of starch (ST) and acrylamide (AM) is a commonly used absorbent material; however, due to their irregular network structure and a limited number of hydrophilic groups, starch-based hydrogels have poor water absorption and water retention. To overcome this, here, we provide a new preparation method for starch-based hydrogels. Using cerium ammonium nitrate (CAN) as an initiator, the starch-acrylamide-cellulose (CMC)/poly(ethylene glycol) (S-A-M/PEG) superabsorbent hydrogel was prepared by graft copolymerization. The starch-acrylamide-cellulose/poly(ethylene glycol) hydrogel network is constructed through the synergistic effect of hydrogen bonds and chemical bonds. The experimental results showed that the starch-acrylamide-cellulose/poly(ethylene glycol) superabsorbent hydrogel has a complete network structure that does not easily collapse due to its superior mechanical properties. The water swelling rate reached 80.24 times, and it reached 50.61% water retention after 16 days. This hydrogel has excellent water-absorbing and water-retaining properties, biocompatibility, and degradability, making it useful for further studies in medical, agricultural, and other fields.

6.
BMC Womens Health ; 21(1): 240, 2021 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-34116668

RESUMO

BACKGROUND: This study aimed to explore the molecular mechanisms of tibolone treatment in postmenopausal women. METHODS: The gene set enrichment profile, GSE12446, which includes 9 human endometrial samples from postmenopausal women treated with tibolone (tibolone group) and 9 control samples (control group), was downloaded from GEO database for analysis. Differentially expressed genes (DEGs) in tibolone vs. control groups were identified and then used for function and pathway enrichment analysis. Protein-protein interaction (PPI) network and module analyses were also performed. Finally, drug-target interaction was predicted for genes in modules, and then were validated in Pubmed. RESULTS: A total of 238 up-regulated DEGs and 72 down-regulated DEGs were identified. These DEGs were mainly enriched in various biological processed and pathways, such as cilium movement (e.g., CCDC114 and DNAI2), calcium ion homeostasis, regulation of hormone levels and complement/coagulation cascades. PPI network contained 368 interactions and 166 genes, of which IGF1, DNALI1, CCDC114, TOP2A, DNAH5 and DNAI2 were the hue genes. A total of 96 drug-gene interactions were obtained, including 94 drugs and eight genes. TOP2A and HTR2B were found to be targets of 28 drugs and 38 drugs, respectively. Among the 94 obtained drugs, only 12 drugs were reported in studies, of which 7 drugs (e.g., epirubicin) were found to target TOP2A. CONCLUSIONS: CCDC114 and DNAI2 might play important roles in tibolone-treated postmenopausal women via cilium movement function. TOP2A might be a crucial target of tibolone in endometrium of postmenopausal women.


Assuntos
Perfilação da Expressão Gênica , Pós-Menopausa , Biologia Computacional , Endométrio , Feminino , Redes Reguladoras de Genes , Humanos , Proteínas Associadas aos Microtúbulos , Norpregnenos
7.
Int J Clin Exp Med ; 8(1): 1066-72, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25785094

RESUMO

OBJECTIVE: Secondary cytoreductive surgery (SCS) is reported to be beneficial for patients with recurrent epithelial ovarian carcinoma (EOC). The current study is to evaluate risk factors that would affect the surgical optimal resection rate and prognosis of recurrent EOC after SCS in Chinese patients. METHODS: In our study, 44 patients with recurrent EOC treated with SCS at Shandong Cancer Hospital were retrospectively reviewed. Patient characteristics were collected and multivariate logistic regression was used to analyze factors that affect the optimal surgical resection rate. The overall survival rate was calculated by the Kaplan-Meier method. Cox proportional-hazards regression was used to analyze risk factors that affect the overall survival of these patients. RESULTS: 90.9% (40/44) patients achieved optimal cytoreductive surgery. Logistic regression did not find any factor that affects the optimal surgical resection rate. Among 24 cases that received chemotherapy before SCS, 18 cases achieved good response and thus had a better survival rate after SCS. Multivariate Cox proportional hazard regression analysis indicated that differentiation, the extent of surgical resection during the initial surgery, and course and efficacy of chemotherapy prior to SCS, and efficacy of chemotherapy after the first recurrence significantly correlated with survival of patients with recurrent cancer (P < 0.05; OR < 1). CONCLUSION: Selection of patients that are suitable to perform SCS will enhance the optimal surgical resection rate. The prognosis of Chinese patients with recurrent EOC after SCS is affected by histologic grade, the extent of residual disease and the effect of chemotherapy after first relapse.

8.
Acta Otolaryngol ; 128(10): 1077-84, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18607891

RESUMO

CONCLUSIONS: The expression of toll-like receptor (TLR) 4 and associated downstream events, such as the activation of signal pathway proteins and inflammatory cytokine production, were down-regulated in the granulation tissues of postoperative mastoid cavity with otorrhea, possibly leading to endotoxin tolerance. OBJECTIVE: The postoperative mastoid cavity is exposed to a high density and diversity of bacteria, but very little is known about how the immune environment is maintained in these regions with otorrhea. In this study, we investigated the changes in the TLR2 and TLR4 signaling pathways and inflammatory cytokine production in the granulation tissues of mastoid cavities with otorrhea and in normal auditory canal skin. MATERIALS AND METHODS: We investigated the expression of TLR2 and TLR4, as well as downstream signal pathway proteins, nuclear factor-kappaB (NF-kappaB) DNA binding, and secretion of tumor necrosis factor-alpha (TNF-alpha) in 28 samples of granulation tissue obtained from the postoperative mastoid cavity with otorrhea and 10 normal external auditory canal skin samples. RESULTS: We found that the frequency of TLR2- and TLR4-positive cells was not increased in granulation tissues relative to normal skin, but the TLR4 mRNA and protein were down-regulated. In this pathophysiological process, there was also a lack of downstream signal pathway protein activation and secretion of TNF-alpha.


Assuntos
Otorreia de Líquido Cefalorraquidiano/cirurgia , Regulação para Baixo , Processo Mastoide/patologia , Receptor 4 Toll-Like/metabolismo , Actinas/metabolismo , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Proteínas I-kappa B/metabolismo , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Masculino , Processo Mastoide/cirurgia , Pessoa de Meia-Idade , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Receptor 2 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Biochem J ; 381(Pt 3): 701-7, 2004 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15104536

RESUMO

A widespread increase in SpmS (spermine synthase) activity has been produced in transgenic mice using a construct in which the human SpmS cDNA was placed under the control of a composite CMV-IE (cytomegalovirus immediate early gene) enhancer-chicken beta-actin promoter. Four separate founder CAG/SpmS mice were studied. Transgenic expression of SpmS was found in all of the tissues examined, but the relative SpmS activities varied widely according to the founder animal and the tissue studied. Very large increases in SpmS activity were seen in many tissues. SpdS (spermidine synthase) activity was not affected. Although there was a statistically significant decline in spermidine content and increase in spermine, the alterations were small compared with the increase in SpmS activity. These results provide strong support for the concept that the levels of the higher polyamines spermidine and spermine are not determined only by the relative activities of the two aminopropyltransferases. Other factors such as availability of the aminopropyl donor substrate decarboxylated S-adenosylmethionine and possibly degradation or excretion must also influence the spermidine/spermine ratio. No deleterious effects of SpmS overexpression were seen. The mice had normal growth, fertility and behaviour up to the age of 12 months. However, breeding the CAG/SpmS mice with MHC (alpha-myosin heavy chain)/AdoMetDC (S-adenosylmethionine decarboxylase) mice, which have a large increase in S-adenosylmethionine decarboxylase expression in heart, was lethal. In contrast, breeding the CAG/SpmS mice with MHC/ODC (L-ornithine decarboxylase) mice, which have a large increase in cardiac ornithine decarboxylase expression, had a protective effect in preventing the small decrease in viability of the MHC/ODC mice.


Assuntos
Regulação Enzimológica da Expressão Gênica/genética , Espermina Sintase/genética , Animais , Encéfalo/enzimologia , Química Encefálica , Cruzamentos Genéticos , Citomegalovirus/genética , Feminino , Vetores Genéticos/genética , Rim/química , Rim/enzimologia , Fígado/química , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Transgênicos , Miocárdio/química , Miocárdio/enzimologia , Especificidade de Órgãos , Ovário/química , Ovário/enzimologia , Filogenia , Poliaminas/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espermina Sintase/metabolismo , Testículo/química , Testículo/enzimologia
10.
Biochem J ; 379(Pt 3): 849-55, 2004 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-14763899

RESUMO

L-ornithine decarboxylase provides de novo putrescine biosynthesis in mammals. Alternative pathways to generate putrescine that involve ADC (L-arginine decarboxylase) occur in non-mammalian organisms. It has been suggested that an ADC-mediated pathway may generate putrescine via agmatine in mammalian tissues. Published evidence for a mammalian ADC is based on (i) assays using mitochondrial extracts showing production of 14CO2 from [1-14C]arginine and (ii) cloned cDNA sequences that have been claimed to represent ADC. We have reinvestigated this evidence and were unable to find any evidence supporting a mammalian ADC. Mitochondrial extracts prepared from freshly isolated rodent liver and kidney using a metrizamide/Percoll density gradient were assayed for ADC activity using L-[U-14C]-arginine in the presence or absence of arginine metabolic pathway inhibitors. Although 14CO2 was produced in substantial amounts, no labelled agmatine or putrescine was detected. [14C]Agmatine added to liver extracts was not degraded significantly indicating that any agmatine derived from a putative ADC activity was not lost due to further metabolism. Extensive searches of current genome databases using non-mammalian ADC sequences did not identify a viable candidate ADC gene. One of the putative mammalian ADC sequences appears to be derived from bacteria and the other lacks several residues that are essential for decarboxylase activity. These results indicate that 14CO2 release from [1-14C]arginine is not adequate evidence for a mammalian ADC. Although agmatine is a known constituent of mammalian cells, it can be transported from the diet. Therefore L-ornithine decarboxylase remains the only established route for de novo putrescine biosynthesis in mammals.


Assuntos
Mamíferos/metabolismo , Putrescina/biossíntese , Agmatina/análise , Agmatina/metabolismo , Animais , Arginina/metabolismo , Dióxido de Carbono/metabolismo , Carboxiliases/análise , Carboxiliases/metabolismo , Extratos Celulares , Clonagem Molecular , Bases de Dados Genéticas , Escherichia coli/enzimologia , Humanos , Rim/enzimologia , Fígado/enzimologia , Camundongos , Mitocôndrias/enzimologia , Ornitina Descarboxilase/genética , Ornitina Descarboxilase/metabolismo , Filogenia , Putrescina/metabolismo , Ratos
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