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1.
Eur J Pharmacol ; 953: 175784, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37179042

RESUMO

Alzheimer's disease (AD), as an advanced neurodegenerative disease, is characterized by the everlasting impairment of memory, which is determined by hyperphosphorylation of intracellular Tau protein and accumulation of beta-amyloid (Aß) in the extracellular space. Minocycline is an antioxidant with neuroprotective effects that can freely cross the blood-brain barrier (BBB). This study investigated the effect of minocycline on the changes in learning and memory functions, activities of blood serum antioxidant enzymes, neuronal loss, and the number of Aß plaques after AD induced by Aß in male rats. Healthy adult male Wistar rats (200-220g) were divided randomly into 11 groups (n = 10). The rats received minocycline (50 and 100 mg/kg/day; per os (P.O.)) before, after, and before/after AD induction for 30 days. At the end of the treatment course, behavioral performance was measured by standardized behavioral paradigms. Subsequently, brain samples and blood serum were collected for histological and biochemical analysis. The results indicated that Aß injection impaired learning and memory performances in the Morris water maze test, reduced exploratory/locomotor activities in the open field test, and enhanced anxiety-like behavior in the elevated plus maze. The behavioral deficits were accompanied by hippocampal oxidative stress (decreased glutathione (GSH) peroxidase enzyme activity and increased malondialdehyde (MDA) levels in the brain (hippocampus) tissue), increased number of Aß plaques, and neuronal loss in the hippocampus evidenced by Thioflavin S and H&E staining, respectively. Minocycline improved anxiety-like behavior, recovered Aß-induced learning and memory deficits, increased GSH and decreased MDA levels, and prevented neuronal loss and the accumulation of Aß plaques. Our results demonstrated that minocycline has neuroprotective effects and can reduce memory dysfunction, which are due to its antioxidant and anti-apoptotic effects.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Fármacos Neuroprotetores , Ratos , Masculino , Animais , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Minociclina/farmacologia , Minociclina/uso terapêutico , Ratos Wistar , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Antioxidantes/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Fármacos Neuroprotetores/metabolismo , Doenças Neurodegenerativas/metabolismo , Modelos Animais de Doenças , Aprendizagem em Labirinto , Hipocampo , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/metabolismo
2.
J Assist Reprod Genet ; 40(2): 343-359, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36593322

RESUMO

PURPOSE: We hypothesized that immature oocytes are associated with impaired energy production in surrounding granulosa cells (GCs) in polycystic ovary syndrome (PCOS). Thus, this study investigated mitochondrial function, determined expression of glycolytic regulatory enzymes, and measured ATP levels in GCs of PCOS patients. METHODS: GCs were isolated from forty-five PCOS patients and 45 control women. Intracellular concentration of reactive oxygen species (ROS), mitochondrial membrane potential (Δψm), the rate of glycolysis, total antioxidant capacity (TAC), activities of catalase (CAT) and superoxide dismutase (SOD), and ATP level were measured in GCs. The gene expression and protein levels of glycolytic enzymes (hexokinase, muscular phosphofructokinase, platelet derived phosphofructokinase, and muscular pyruvate kinase) were determined. Association of GC energy level with oocyte maturation was further validated by measuring glycolysis rate and ATP level in GCs isolated from mature and immature follicles from new set of fifteen PCOS patients and 15 controls. RESULTS: PCOS patients showed higher ROS level, decreased TAC, reduced CAT and SOD activities, and lower Δψm together with reduced expression of key glycolytic enzymes. ATP concentration and biochemical pregnancy were lower in PCOS compared with control group. ATP levels were found to be significantly correlated with ROS and Δψm (r = - 0.624 and r = 0.487, respectively). GCs isolated from immature follicles had significantly lower ATP levels and rate of glycolysis compared with the GCs separated from mature follicles in both PCOS patients and control. CONCLUSION: Declined energy due to the mitochondrial dysfunction and restrained glycolysis in GCs is associated with the immature oocytes and lower biochemical pregnancy in PCOS.


Assuntos
Síndrome do Ovário Policístico , Gravidez , Humanos , Feminino , Síndrome do Ovário Policístico/genética , Síndrome do Ovário Policístico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Células da Granulosa/metabolismo , Antioxidantes/metabolismo , Fosfofrutoquinases/genética , Fosfofrutoquinases/metabolismo , Trifosfato de Adenosina/metabolismo
3.
J Reprod Infertil ; 23(3): 148-159, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36415496

RESUMO

Background: Granulosa cells (GCs) play key roles in oocyte maturation by providing required estradiol (E2). Since the presence of immature oocytes has been reported in cases with polycystic ovary syndrome (PCOS), in this study, the levels of mitochondrial membrane transporter proteins involved in E2 synthesis were determined. E2 concentration and parameters of oxidative status were also measured in follicular fluids of PCOS women. Methods: Forty-three women with PCOS and 43 healthy women who were candidates for IVF procedure due to their husbands' infertility were enrolled in this case-control study. The gene expression and protein levels of mitochondrial translocator protein (TSPO) and voltage-dependent anion channel 1 (VDAC1) were determined in GCs using RT-qPCR and immunocytochemistry assay, respectively. E2 level was measured with electrochemiluminescence, whereas total cholesterol, total antioxidant capacity (TAC), total oxidant status (TOS), and malondialdehyde (MDA) were determined using colorimetric methods in follicular fluids. Data were analyzed using unpaired t-test or Mann-Whitney U test, and Spearman's correlation coefficient. Results: VDAC1 and TSPO were significantly lower in mRNA (p<0.05) and protein levels (p<0.001) of PCOS patients. PCOS patients had lower cholesterol, estradiol, and TAC levels, and higher TOS and MDA contents. E2 level had direct correlation with VDAC1, TSPO, and TAC while it was negatively correlated with TOS, oxidative stress index (OSI), and MDA (p<0.001). Higher E2 levels were associated with higher numbers of high-quality oocytes and conceived embryos (p<0.001). Conclusion: Decreased E2 levels and increased oxidative stress in the follicular fluid may be the cause of immature oocytes in PCOS cases.

4.
J Chem Neuroanat ; 125: 102158, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36084891

RESUMO

OBJECTIVES: Minocycline hydrochloride is a semi-synthetic, second-generation tetracycline with neuroprotective, neurorestorative, anti-amyloidogenic, anti-inflammatory, antioxidant, and anti-apoptotic properties. The present study was designed to investigate the potential protective effects of minocycline against beta-amyloid (Aß)-induced Alzheimer's disease (AD), recognition memory decline, and the possible involved anti-apoptotic mechanisms. METHODS: The rats were treated with minocycline (50 and 100 mg/kg/day; P.O.) after AD induction for 30 days. Behavioral functions were assessed by employing standard behavioral tests, including novel object recognition (NOR) and passive avoidance learning (PAL) tasks. Then, total antioxidant capacity (TAC) and total oxidant status (TOS) were measured in blood serum using ELISA kits. Apoptosis and the number of Aß plaques were examined by the TUNEL and Congo red staining, respectively. RESULTS: Treatment of Aß rats with minocycline improved memory deficit in the PAL task and a decline in recognition memory in the NOR test. Minocycline at 50 and 100 mg/kg significantly reduced the TOS levels and increased the TAC levels (P < 0.0001). Also, minocycline at 50 and 100 mg/kg reduced the apoptotic index in the hippocampus of Aß rats. After Congo red staining, the minocycline group showed improved cell morphology and markedly fewer Aß plaques. CONCLUSIONS: Minocycline reduced memory and learning deficit in behavioral experiments after Aß injection, which may be due to its anti-inflammatory and anti-apoptotic effects.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Ratos , Animais , Masculino , Peptídeos beta-Amiloides/metabolismo , Minociclina/farmacologia , Minociclina/uso terapêutico , Antioxidantes/farmacologia , Vermelho Congo/farmacologia , Hipocampo/metabolismo , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/tratamento farmacológico , Placa Amiloide , Aprendizagem da Esquiva , Anti-Inflamatórios/farmacologia , Modelos Animais de Doenças , Fragmentos de Peptídeos/farmacologia
5.
Int J Biol Macromol ; 217: 824-841, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-35905760

RESUMO

Since autologous stem cell transplantation is prone to cancer recurrence, in vitro sperm production is regarded a safer approach to fertility preservation. In this study, the spermatogenesis process on testicular tissue extracellular matrix (T-ECM)-derived printing structure was evaluated. Ram testicular tissue was decellularized using a hypertonic solution containing triton and the extracted ECM was used as a bio-ink to print an artificial testis. Following cell adhesion and viability examination, pre-meiotic and post-meiotic cells in the study groups (as testicular suspension and co-culture with Sertoli cells) were confirmed by real-time PCR, flow-cytometry and immunocytochemistry methods. Morphology of differentiated cells was evaluated using transmission electron microscopy (TEM), toluidine blue, Giemsa, and hematoxylin and eosin (H&E) staining. The functionality of Leydig and Sertoli cells was determined by their ability for hormone secretion. The decellularization of testicular tissue fragments was successful and had efficiently removed the cellular debris and preserved the ECM compounds. High cell viability, colonization, and increased expression of pre-meiotic markers in cultured testicular cells on T-ECM-enriched scaffolds confirmed their proliferation. Furthermore, the inoculation of neonatal mouse testicular cells onto T-ECM-enriched scaffolds resulted in the generation of sperm. Morphology evaluation showed that the structure of these cells was quite similar to mature sperm with a specialized tail structure. The hormonal analysis also confirmed production and secretion of testosterone and inhibin B by Leydig and Sertoli cells. T-ECM printed artificial testis is a future milestone that promises for enhancing germ cell maintenance and differentiation, toxicology studies, and fertility restoration to pave the way for new human infertility treatments in the future.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Testículo , Animais , Matriz Extracelular , Humanos , Recém-Nascido , Masculino , Camundongos , Impressão Tridimensional , Sêmen , Espermatogênese , Espermatogônias/metabolismo , Espermatozoides , Testículo/metabolismo , Transplante Autólogo
6.
Int J Reprod Biomed ; 20(4): 299-306, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35822186

RESUMO

Background: Methylenetetrahydrofolate reductase enzyme (MTHFR) plays a key role in regulating folate balance, converting homocysteine to methionine, and producing s-adenosylmethionine (SAM) that plays a role in the methylation process. Objective: This study aimed to determine MTHFR activity and SAM level in men with normozoospermia and oligozoospermia. Materials and Methods: 30 oligozoospermic and 30 normozoospermic men as controls were enrolled in this case-control study. Semen analysis was conducted according to the world health organization criteria. All semen samples were collected after 3-5 days of sexual abstinence. The sperms were evaluated by sperm test video software. All subjects SAM level was measured by enzyme-linked immunosorbent assay kit, and MTHFR were measured manually. Results: 2 groups had a significant difference in sperm morphology (p = 0.02), concentration (p = 0.02) and motility (p = 0.03). The MTHFR activity in normozoospermic and oligozoospermic groups had significantly differences (p = 0.01). The level of SAM in the semen of oligozoospermic men was statistically lower than normozoospermic men (p = 0.03). Also, there was a positive association between MTHFR enzyme activity and SAM level in the normozoospermia group (p = 0.02, ß = 0.67) and oligozoospermia group (p = 0.03, ß = 0.54). Conclusion: MTHFR activity and SAM concentration were statistically lower in oligozoospermia men. It seems they can affect sperm concentration, morphology, and motility.

7.
Andrologia ; 54(1): e14258, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34609765

RESUMO

Low motility is one of the causes of male infertility. In this study, the effects of progesterone solid lipid nanoparticles (SLNs) on sperm capacitation, acrosome reaction, oxidative stress and expression of SPACA1 and MAPK way genes were investigated. Progesterone SLNs were synthesized using the solvent emulsification evaporation method. Twenty asthenozoospermia samples were selected, and sperm and acrosome membrane integrity, acrosome reaction, sperm motility, viability, total antioxidant capacity (TAC), total oxidative status tests and PKA, PTK, P38MAPK and SPACA1 gene expressions were assessed. The synthesized nanoparticles were prepared with the size (187.6 nm), PDI (0.184), EE (85.82%), LP (3.43%) and ZP (-23.5mV). Progesterone SLNs increased sperm and acrosome membrane integrity and TAC (p < .05). Also, the expression of P38MAPK, PKA, PTK, and SPACA1 genes in this group showed a significant increase (p < .001). Progesterone SLNs increased acrosome reaction, sperm capacitation and TAC. Also, it increased the expression of PTK PKA, SPACA1 and P38MAPK genes.


Assuntos
Astenozoospermia , Nanopartículas , Acrossomo , Reação Acrossômica , Astenozoospermia/tratamento farmacológico , Astenozoospermia/genética , Humanos , Lipossomos , Masculino , Progesterona/farmacologia , Capacitação Espermática , Motilidade dos Espermatozoides , Espermatozoides
8.
Int J Biochem Cell Biol ; 141: 106089, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34601090

RESUMO

Alzheimer's disease (AD) is one of the common neurodegenerative diseases characterized by memory impairment. The protective effects of stem cell-based therapy have been reported in AD. In this study, it was assumed that Chitosan-coated Selenium nanoparticles (ChSeNPs) increase the efficiency of stem cells in the attenuation of neurotoxicity in the rat AD model. The AD model was induced using Streptozotocin (STZ) and treated by the adipose-derived mesenchymal stem cells (AMSCs) and SeNPs/ChSeNPs (0.4 mg/kg). Passive avoidance learning and recognition memory were assessed using shuttle box and novel object recognition tasks. The amyloid-beta deposition, the injected cells' homing and survival, antioxidant capacity, and BDNF concentration were evaluated using the histological, biochemical, and ELISA methods. The results showed that the combined administration of ChSeNPs and AMSCs is more effective in increasing the step-through latency and discrimination index than administering SeNPs and stem cells. Combined therapy caused a significant increase in antioxidant capacity that ChSeNPs was more effective than SeNPs, while AMSCs beside SeNPs had a greater effect on BDNF levels compared to conventional treatment of nanoparticles or AMSCs alone. Ultimately, the homing and survival of the transplanted AMSCs were greater in the group that received both stem cells and ChSeNPs. Taken together, it seems that the administration of ChSeNPs enhances the efficiency of transplanted stem cells in decreasing the neurotoxicity induced by STZ through an increase in the antioxidant capacity.


Assuntos
Selênio , Estreptozocina , Animais , Masculino , Nanopartículas , Neuroproteção , Ratos , Células-Tronco
9.
Int J Reprod Biomed ; 19(7): 589-598, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34458667

RESUMO

BACKGROUND: Cerium dioxide nanoparticles (CNPs) due to the antidiabetic and antioxidant activities are proposed for the treatment of oxidative stress-associated diseases. OBJECTIVE: To examine the impact of CNPs on hyperglycemia-induced apoptosis and oxidative stress in the testis of diabetic rats. MATERIALS AND METHODS: Twenty-four male rats were divided into four groups (n = 6/each) as diabetic rats, CNPs group, diabetic + CNPs rats, and controls. The control group was fed only mouse food and water. Rats became diabetic through receiving streptozotocin (STZ) 60 mg/kg. CNPs were given to the rats at a dose of 30 mg/kg daily for 2 wk. Malondialdehyde and total thiol group (TTG) levels were measured using spectrofluorometer. Expression of b-cell lymphoma protein 2-associated X protein (BAX) and b-cell lymphoma protein 2 (Bcl-2) were investigated using quantitative real-time polymerase chain reaction. Western blot analysis was used to examine caspase 3 protein levels. RESULTS: The content of malondialdehyde significantly increased in the STZ-diabetic rats, while TTG levels demonstrated a remarkable decrease. Caspase-3, BAX, and BAX/Bcl-2 mRNA ratio raised significantly in the STZ-diabetic rats. On the other hand, Bcl-2 mRNA levels reduced in the testis of diabetic rats (p = 0.006). Intervention with CNPs caused a substantial increase in the TTG levels, while the malondialdehyde contents, caspase-3, BAX levels, as well as BAX/Bcl-2 mRNA ratio were considerably decreased following CNPs treatment. Administration of CNPs increased mRNA levels of Bcl-2 (p < 0.0001). CONCLUSION: CNPs treatment attenuates testicular apoptosis and oxidative stress induced by diabetes. This nanoparticle might be suggested for the treatment of diabetes-associated reproductive disorders.

10.
Biomater Sci ; 9(9): 3465-3484, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33949391

RESUMO

Testicular scaffolds may be an option for fertility preservation. The aim was to develop various procedures for the decellularization of testicular tissue and to design a bio-ink to construct a bioartificial testis. Ram testicular tissue fragments were decellularized using NaCl buffer, NaCl buffer-Triton, SDS and SDS-Triton. The removal of the cells from the tissues was confirmed by DAPI and H & E staining, as well as the evaluation of the DNA content. Alcian blue, Orcein and Masson's trichrome staining methods were also used to confirm that T-ECM was preserved intact. Then, the optimal decellularization protocol was selected to determine the parameters of the bio-ink and printing of the scaffold. The extracted T-ECM was used to print the hydrogel scaffold in combination with alginate-gelatin. The printability, morphological, mechanical and biological properties of the printed hydrogels were characterized. Decellularization of testicular tissue fragments using the NaCl buffer-Triton protocol was significantly more efficient than other decellularization methods in removing the cellular debris and preserving the T-ECM compounds. The 3D printed scaffold with 5% T-ECM showed a uniform surface morphology with high cell attachment and cyto-biocompatibility properties for spermatogonia stem cells in vitro and in vivo compared to other groups. It is concluded that T-ECM can be used as a biomimetic material to make an artificial testis with possible in vitro sperm production.


Assuntos
Testículo , Tecidos Suporte , Matriz Extracelular , Tinta , Masculino , Impressão Tridimensional , Engenharia Tecidual
11.
Metab Brain Dis ; 36(6): 1259-1266, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33826055

RESUMO

Alzheimer's disease is the most common neurodegenerative disease associated with deposition of amyloid-beta and the increased oxidative stress. High free radical scavenging ability of selenium nanoparticles (SeNPs) has been acknowledged, so in the present study, the effects of treatment with SeNPs on Streptozotocin (STZ)-induced neurotoxicity were evaluated in the male rats. Learning and memory impairment was induced by intraventricular injection of STZ. Following induction of memory impairment, the rats received 0.4 mg/kg of SeNPs daily for one month. Memory function, antioxidant capacity, and deposition of Amyloid ß (Aß) were assessed using the shuttle box task, biochemical methods, and Congo red staining. Injection of STZ caused memory impairment, a decrease in the level of total thiol group (TTG), and an increase in the malondialdehyde (MDA) content and deposition of Aß. Administration of SeNPs reversed the neurotoxicity induced by STZ. It seems that SeNPs likely had neuroprotective effects on the animal model of Alzheimer's disease through increasing antioxidants҆ capacity.


Assuntos
Antibacterianos/toxicidade , Antioxidantes/uso terapêutico , Nanopartículas/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Síndromes Neurotóxicas/tratamento farmacológico , Selênio/uso terapêutico , Estreptozocina/toxicidade , Peptídeos beta-Amiloides/metabolismo , Animais , Antibacterianos/administração & dosagem , Antioxidantes/administração & dosagem , Aprendizagem da Esquiva/efeitos dos fármacos , Injeções Intraventriculares , Deficiências da Aprendizagem/induzido quimicamente , Deficiências da Aprendizagem/psicologia , Masculino , Transtornos da Memória/induzido quimicamente , Transtornos da Memória/psicologia , Fármacos Neuroprotetores/administração & dosagem , Síndromes Neurotóxicas/psicologia , Ratos , Ratos Wistar , Selênio/administração & dosagem , Estreptozocina/administração & dosagem
12.
Arch. endocrinol. metab. (Online) ; 65(1): 60-66, Jan.-Feb. 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1152880

RESUMO

ABSTRACT Objective: A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) and ADAMTS-5 normal expression levels are essential for ovulation and subsequent fertilization. The objective of the present study was to assess expression pattern of these genes in cumulus cells (CCs) taken from patients with polycystic ovary syndrome (PCOS) and to investigate any possible relationship with the oocyte quality. Subjects and methods: ADAMTS-4 and -5 expression levels within CCs containing oocytes at the metaphase II (MII) and germinal vesicle (GV) stages, taken from 35 patients with PCOS and 35 women with normal ovarian function, were investigated using RT-qPCR. Moreover, possible correlations between ADAMTS-4, ADAMTS-5, and progesterone receptors (PRs) expression as well as oocyte quality were evaluated. Results: ADAMTS-4 and -5 expression levels were dramatically diminished in the CCs of the PCOS patients when compared to the controls. ADAMTS-4 and -5 expression levels were correlated with each other and with the oocyte quality. Furthermore, lower expression levels of ADAMTS-4 and -5 in the PCOS patients were strongly correlated with the diminished PRs expression levels. Conclusions: Downregulation of ADAMTS-4 and -5 in the human CCs of the PCOS patients correlated with the decline in the PRs expression, and impaired oocyte quality may cause lower oocyte recovery, maturation, and fertilization rate.


Assuntos
Feminino , Humanos , Oócitos , Síndrome do Ovário Policístico , Síndrome do Ovário Policístico/genética , Proteína ADAMTS4/genética , Proteína ADAMTS5/genética , Regulação para Baixo
13.
Arch Endocrinol Metab ; 65(1): 60-66, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33444494

RESUMO

OBJECTIVE: A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) and ADAMTS-5 normal expression levels are essential for ovulation and subsequent fertilization. The objective of the present study was to assess expression pattern of these genes in cumulus cells (CCs) taken from patients with polycystic ovary syndrome (PCOS) and to investigate any possible relationship with the oocyte quality. METHODS: ADAMTS-4 and -5 expression levels within CCs containing oocytes at the metaphase II (MII) and germinal vesicle (GV) stages, taken from 35 patients with PCOS and 35 women with normal ovarian function, were investigated using RT-qPCR. Moreover, possible correlations between ADAMTS-4, ADAMTS-5, and progesterone receptors (PRs) expression as well as oocyte quality were evaluated. RESULTS: ADAMTS-4 and -5 expression levels were dramatically diminished in the CCs of the PCOS patients when compared to the controls. ADAMTS-4 and -5 expression levels were correlated with each other and with the oocyte quality. Furthermore, lower expression levels of ADAMTS-4 and -5 in the PCOS patients were strongly correlated with the diminished PRs expression levels. CONCLUSION: Downregulation of ADAMTS-4 and -5 in the human CCs of the PCOS patients correlated with the decline in the PRs expression, and impaired oocyte quality may cause lower oocyte recovery, maturation, and fertilization rate.


Assuntos
Proteína ADAMTS4/genética , Proteína ADAMTS5/genética , Oócitos , Síndrome do Ovário Policístico , Regulação para Baixo , Feminino , Humanos , Síndrome do Ovário Policístico/genética
14.
Microsc Res Tech ; 84(3): 563-570, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33026138

RESUMO

A silicon microring circuit embedded gold film with unique characteristics is proposed for Hall effect, current, and temperature sensing applications. The microring circuit is operated by the input polarized laser sources, in which the space-time distortion control can be employed. A gold film is embedded at the microring center. The whispering gallery mode (WGM) is generated and applied for plasmonic waves, from which the trapped electron cloud oscillation is formed. Through the input port, the input polarized light of 1.55 µm wavelength fed into the space-time control circuit. Spin-up |↑〉(|0〉) and spin-down |↓〉(|1〉) of polarized electrons result when the gold film is illuminated by the WGM. The electric current passing through the gold film generates a magnetic field (B), which is orthogonal to the electric field. Hall voltage is obtained at the output of the circuit, from which the microring space-time circuit can operate for Hall's effect, current, and temperature sensing device. The simulation results obtained have shown that when the input power of 100-500 mW is applied, the optimum Hall effect, current, and temperature sensitivities are 0.12 µVT-1 , 0.9 µVA-1 , and 6.0 × 10-2 µVK-1 , respectively. The Hall effects, current, and temperature sensors have an optimum response time of 1.9 fs.

15.
Chemosphere ; 268: 129348, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33360001

RESUMO

A novel adsorbent was developed based on nitrile functionalized calix [4]arene grafted onto magnetic graphene oxide (N-Calix-MGO) for remediation of arsenic (III) ions from aqueous media. The nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The effective parameters on adsorption efficiency such as pH, adsorbent dosage, contact time, initial concentration, and temperature were studied. The adsorption process was provided with a high removal efficiency up to (90%) at pH 6 which followed by IUPAC Type II pattern. The mathematical models of kinetics and isotherm validated the experimental process. The adsorption kinetic is followed pseudo-first-order model with R2 > 0.9. The adsorption equilibrium was well fitted on the Freundlich model (R2 ∼ 0.96) as compared Langmuir model (R2 ∼ 0.75). Hence, the Freundlich model suggested a multilayer sorption pattern with a physisorption mechanism for arsenic (III) uptake ono developed nanocomposite with a sorption capacity of 67 mg/g for arsenic. The Gibbs free energy (ΔG° < -20 kJ/mol) showed As(III) uptake ono N-Calix-MGO nanocomposite was the physical adsorption mechanism.


Assuntos
Arsênio , Calixarenos , Poluentes Químicos da Água , Adsorção , Grafite , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Nitrilas , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
16.
Reprod Sci ; 28(7): 1788-1811, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33140326

RESUMO

Few studies have been conducted on the paternal effects on embryogenesis as compared with studies on maternal effects. The fertility potential of sperm decreases with genomic material abnormalities. Damaged DNA of sperm has been correlated with poor fertilization, reduced implantation and pregnancy rates, and increased production of aneuploid embryos. Evidence suggests that the role of sperm in embryogenesis goes beyond genomic material transfer, and centrosomes, sperm-derived cytoplasmic factors, paternal mRNA, and small RNAs are essential for early embryonic development. Epigenetic factors like histone modification and DNA methylation participate in the regulation of gene expression in sperm. The etiology of sperm chromatin abnormalities is important in male fertility and may affect reproductive outcomes. Success in implantation depends on the quality of the fertilized sperm and oocyte as well as the type of assisted reproductive techniques. Therefore, male factors affecting development of embryo can play a role in the failure of assisted reproductive techniques. Further studies are needed to evaluate clinical aspects and the risks of transmitting genetic or epigenetic disorders to provide safe therapies for infertility.


Assuntos
Blastocisto/fisiologia , Desenvolvimento Embrionário/fisiologia , Fertilização In Vitro/métodos , Espermatozoides/metabolismo , Metilação de DNA , Feminino , Humanos , Masculino
17.
Mater Sci Eng C Mater Biol Appl ; 117: 111293, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32919654

RESUMO

A Double-Gate Armchair-Graphene Nanoribbon FET is proposed to realize a high-sensitive and small-size biosensor in order to detect DNA without high-cost and time-consuming labeling process. Two nanogap cavities open inside the top and bottom gate oxides by the method of sacrificed layer etching. When the DNA biomolecule is introduced to the nanogap cavity, the hybridization event which is actually the formation of a double-strand of DNA will occur thus electrically modulating the GNR channel leading to a change in the drain current. The important report of this research is about attained high sensitivity of the proposed biosensor for a vast spectrum of the DNA biological samples. It is worth noting that a DNA sequence by 23 nucleotides extracted from Neisseria gonorrhoeae can be detected as a special case. An extensive numerical approach has been applied in order to characterize the proposed biosensor. The suggested biosensor has been evaluated by solving Schrödinger equation )SE( with Non-Equilibrium Green Function (NEGF) method in the mode-space coupled into Poisson solver in a self-consistent manner assuming ballistic limit. Two different expressions of sensitivity in terms of the threshold voltage and current have been defined giving a good metric for the sensitivity analysis. The results revealed a relative sensitivity of 1 mV/nm2 by a filled area by the DNA about 120 nm2 showing the excellent superiority for the proposed biosensor as compared to other counterparts. The effective area of the proposed biosensor obtains 240 nm2 which is very small in comparison with other reports highlighting high capability of the biosensor in the detection. It has been shown that the proposed biosensor can be implemented in ultra-scaling domain resulting in considerable increase in the sensitivity promising a potent and reliable candidate for high-sensitive and small-size biosensors. Also, the technical issues on designing the suggested biosensor have been investigated to achieve a useful guideline in detection and identification of the target DNAs.


Assuntos
Técnicas Biossensoriais , Grafite , Nanotubos de Carbono , DNA , Hibridização de Ácido Nucleico
18.
Microsc Res Tech ; 83(10): 1217-1224, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32473066

RESUMO

A 3D (three-dimensional) quantum interferometer consisting of a silicon microring circuit proposed. The interferometer based on the electron spin cloud projections generated by microring-embedded gold grating. The electron cloud oscillations result from the excitation of the gold grating at the center of the silicon microring by the dark soliton pulse of 1.50 µm center wavelength. The electron cloud spin-down, spin-up automatically formed in the two axes (x, y, respectively) and propagated along the z-axis. In this proposal, the sensing mechanism of the circuit is manipulated by varying the reflector gold lengths of the sensing arm. The electron cloud spin coupled and changed by changing the gold lengths. The sensitivity measurement of the 3D quantum interferometer for three gold layer lengths of 100 nm, 500 nm, and 1,000 nm is (47.62 nm fs-1 , ±0.4762 fs-1 , ±0.01 nm-1 ), (238.10 nm fs-1 , ±0.4762 fs-1 , ±0.002 nm-1 ), (476.20 nm fs-1 , ±0.4762 fs-1 , ±0.001 nm-1 ), respectively. The used circuit parameters are the real ones that can be fabricated by the currently available technology. Moreover, the silicon micro ring circuit acts as a plasmonic antenna, which can apply for wireless quantum communication. The electron cloud spin projection space-time control can apply for quantum cellular automata.

19.
Micromachines (Basel) ; 11(1)2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32284498

RESUMO

A single-mode optical fiber sensor uses surface plasmon resonance (SPR) with a bimetallic silver-copper (Ag-Cu) coating compared to a single layer of Ag and Cu itself. Bimetallic Ag-Cu sensors are constructed by simple fabrication on a side-polished optical fiber, followed by an electron beam evaporation of Ag and Cu films. For this investigation, the thickness of the single Ag layer was set to 30 nm and the single Cu layer was set to 30 nm; whereas for the bimetallic combined Ag-Cu layer the thickness of Ag was 7 nm and Cu 23 nm. The sensor performance was analyzed and compared experimentally and numerically using the COMSOL Multiphysics. A white light source was used with a broad optical bandwidth to provide a range of wavelengths to the optical fiber. The characteristics of the thin layers of Ag, Cu, and Ag-Cu as alcohol sensors were evaluated. We found that Cu was the most sensitive metallic layer compared to the Ag and the bimetallic Ag-Cu layers. For a 100% alcohol concentration, Cu showed a sensitivity of 425 nm/RIU followed by the bimetallic Ag-Cu layer with 108.33 nm/RIU, whereas the Ag layer was not detected. Interestingly, sensitivity reached saturation beyond the 20 nm thick layer of Ag. This shows that the Cu and the bimetallic Ag-Cu layers are suitable for an alcohol-based optical sensor.

20.
Life Sci ; 249: 117482, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32135186

RESUMO

AIMS: Improving the environment of the injured area and the preconditioning of mesenchymal stem cells (MSCs) are promising approaches to optimize the therapeutic properties of transplanted MSCs. Herein we investigated the synergistic effects of treadmill exercise and dimethyloxalylglycine (DMOG)-preconditioned stem cells in an Alzheimer's disease (AD) animal model. MATERIALS AND METHODS: The MSCs were treated with DMOG for 24 h and transplanted in the AD model intravenously. In addition to cell transplantation, the rats went on treadmill exercise for one month. Memory function, BDNF expression, neurogenesis, apoptosis, and antioxidant capacity were assessed using shuttle box and Morris water maze tasks, ELISA, immunohistochemistry, western blot, and biochemical methods. KEY FINDINGS: Transplantation of DMOG-treated cells caused a memory improvement compared to the AD group via an increase in neurogenesis and expression of nestin, Sox-2, and NeuroD. Moreover, the injection of preconditioned cells was more effective in increasing the total antioxidant capacity and the BDNF level and decreasing the MDA and caspase-3 than the non-treated cells. Treadmill exercise improved spatial memory and learning through an increase in BDNF and neurogenesis. Finally, treadmill exercise and transplantation of the treated cells together had the most neuroprotective effects. SIGNIFICANCE: It seems that the transplantation of DMOG-treated cells besides exercise may have protective effects in the AD model via an increase in BDNF, antioxidants, and neurogenesis and a decrease in apoptosis.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Memória , Neurogênese , Condicionamento Físico Animal , Células-Tronco/citologia , Animais , Masculino , Ratos , Ratos Wistar
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