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Filaments driven by bound motor proteins and chains of self-propelled colloidal particles are a typical example of active polymers (APs). Due to deformability, APs exhibit very rich dynamic behaviors and collective assembling structures. Here, we are concerned with a basic question: how APs behave near a single obstacle? We find that, in the presence of a big single obstacle, the assembly of APs becomes a two-state system, i.e. APs either gather nearly completely together into a giant jammed aggregate (GJA) on the surface of the obstacle or distribute freely in space. No partial aggregation is observed. Such a complete aggregation/collection is unexpected since it happens on a smooth convex surface instead of, e.g., a concave wedge. We find that the formation of a GJA experiences a process of nucleation and the curves of the transition between the GJA and the non-aggregate state form hysteresis-like loops. Statistical analysis of massive data on the growing time, chirality and angular velocity of both the GJAs and the corresponding nuclei shows the strong random nature of the phenomenon. Our results provide new insights into the behavior of APs in contact with porous media and also a reference for the design and application of polymeric active materials.
Assuntos
PolímerosRESUMO
OBJECTIVE: To study the risk factors for elevated serum total bile acid (TBA) in preterm infants. METHODS: A retrospective analysis was performed for the clinical data of 216 preterm infants who were admitted to the neonatal intensive care unit. According to the presence or absence of elevated TBA (TBA >24.8 µmol/L), the preterm infants were divided into elevated TBA group with 53 infants and non-elevated TBA group with 163 infants. A univariate analysis and an unconditional multivariate logistic regression analysis were used to investigate the risk factors for elevated TBA. RESULTS: The univariate analysis showed that there were significant differences between the elevated TBA group and the non-elevated TBA group in gestational age at birth, birth weight, proportion of small-for-gestational-age infants, proportion of infants undergoing ventilator-assisted ventilation, fasting time, parenteral nutrition time, and incidence of neonatal respiratory failure and sepsis (P<0.05). The unconditional multivariate logistic regression analysis showed that low birth weight (OR=3.84, 95%CI: 1.53-9.64) and neonatal sepsis (OR=2.56, 95%CI: 1.01-6.47) were independent risk factors for elevated TBA in preterm infants. CONCLUSIONS: Low birth weight and neonatal sepsis may lead to elevated TBA in preterm infants.
Assuntos
Ácidos e Sais Biliares/sangue , Recém-Nascido Prematuro/sangue , Feminino , Humanos , Recém-Nascido de Baixo Peso/sangue , Recém-Nascido , Modelos Logísticos , Masculino , Estudos Retrospectivos , Fatores de Risco , Sepse/sangueRESUMO
Objective: To compare the incidences of Y chromosome microdeletion between patients with azoospermia or severe oligozoospermia with varicocele( VC) and those without VC and investigate the etiopathogenisis of their infertility. Methods: We included 137 VC patients in group A(70 with azoospermia as group A1 and 67 with severe oligozoospermia as group A2),135 non-VC patients in group B(69 with azoospermia as group B1 and 66 with severe oligozoospermia as group B2),and 30 normal fertile men as controls in group C. We detected Y chromosome microdeletion in different groups using multiplex PCR. Results: Y chromosome microdeletion was detected in 23(16. 8%) of the patients in group A, another 23(17. 0%) in group B,and 0 in group C. The rates of Y chromosome microdeletion were 22. 9% in group A1,10. 4% in group A2,20. 3% in group B1,and 13. 6% in group B2,and the microdeletion rate in the patients with severe oligozoospermia( groups A1 and B1) was 23. 3%(31 /133). No statistically significant difference was found between groups A and B( P > 0. 05). Conclusion: There are no significant differences in the rate of Y chromosome microdeletion between varicocele and non-varicocele patients with azoospermia or severe oligozoospermia, and Y chromosome microdeletion is one of the causes of azoospermia and severe oligozoospermia with varicocele.
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Azoospermia/genética , Infertilidade Masculina/genética , Oligospermia/genética , Transtornos do Cromossomo Sexual no Desenvolvimento Sexual/genética , Varicocele/complicações , Estudos de Casos e Controles , Deleção Cromossômica , Cromossomos Humanos Y/genética , Humanos , Incidência , Masculino , Aberrações dos Cromossomos SexuaisRESUMO
BACKGROUND: Soft pancreas is widely recognized as an important risk factor for the development of postoperative pancreatic fistula (POPF). Although fatty pancreas (FP) has not been formally defined as a cause of pancreatic fistula, existing research has shown that it can increase the incidence of POPF by increasing pancreatic tenderness; therefore, it may be a potential risk factor. This study aimed to discern whether FP was associated with POPF. METHOD: Two reviewers independently performed literature searches from five electronic databases. According to the established inclusion criteria, we extracted necessary data from the studies that met the criteria for further analysis. We pooled the odds ratios (ORs) from individual studies using a random-effects model to investigate the associations between POPF and the prognosis of FP. RESULT: A total of 11 studies involving 2484 individuals were included. The pooled prevalence of POPF was 18% (95% CI: 12-24%). Body mass index (BMI) was associated with a significantly increased risk of POPF (OR=3.55; 95% CI: 1.83, 6.86; P=0.0002; I²=0). FP was obviously associated with the occurrence of POPF (OR=3.75; 95% CI: 1.64, 8.58; P=0.002; I²=78). CONCLUSION: FP is closely associated with the development of POPF, and the early identification of these high-risk patients can help to reduce the incidence of POPF. SYSTEMATIC REVIEW REGISTRATION: The Registration URL link is (https://www.crd.york.ac.uk/PROSPERO/). The ID is "CRD42021265141".
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PURPOSE: Alzheimer's disease is the most common neurodegenerative disease, characterized by accumulation of amyloid ß peptides. MicroRNAs have been identified as significant regulators and therapeutic targets of Alzheimer's disease. However, the roles of miR-16-5p and miR-19b-3p and their mechanisms in Alzheimer's disease progression remain largely unknown. MATERIALS AND METHODS: Amyloid ß-treated SH-SY5Y cells were used to study Alzheimer's disease progression in vitro. Transfection was conducted into SH-SY5Y cells using Lipofectamine 2000. The expression levels of miR-16-5p, miR-19b-3p and beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) were measured by quantitative real-time PCR or western blot, respectively. Cell viability and apoptosis were detected in amyloid ß-treated SH-SY5Y cells by MTT or flow cytometry, respectively. The interaction between BACE1 and miR-16-5p or miR-19b-3p was explored by luciferase reporter and RNA immunoprecipitation analyses. RESULTS: The expression levels of miR-16-5p and miR-19b-3p were reduced but BACE1 protein expression was enhanced in SH-SY5Y cells after treatment of amyloid ß. Overexpression of miR-16-5p or miR-19b-3p attenuated amyloid ß-induced viability inhibition and apoptosis promotion in SH-SY5Y cells, while their knockdown exacerbated amyloid ß-induced injury. BACE1 was confirmed as a target of miR-16-5p and miR-19b-3p and its overexpression aggravated amyloid ß-induced loss of viability and production of apoptosis, while its depletion caused an opposite effect. Moreover, upregulation of BACE1 alleviated the regulatory effects of miR-16-5p and miR-19b-3p on amyloid ß-induced injury. CONCLUSION: MiR-16-5p and miR-19b-3p relieved amyloid ß-induced injury by targeting BACE1 in SH-SY5Y cells, indicating miR-16-5p and miR-19b-3p as protective agents for treatment of Alzheimer's disease.
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Doença de Alzheimer , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/toxicidade , Ácido Aspártico Endopeptidases/metabolismo , MicroRNAs/metabolismo , Neurônios/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Linhagem Celular Tumoral , Regulação da Expressão Gênica/fisiologia , Humanos , Neurônios/patologiaRESUMO
Objective. Hypertension is one of the most common cardiovascular disorders with high mortality. Here we explored the antihypertension effects of Huanglian Jiedu Decoction (HJD) on thoracic aorta gene expression in spontaneous hypertensive rats. Methods. A rat model of spontaneous hypertension was used. The gene change profile of thoracic aorta after JHD treatment was assessed by GeneChip(GC) analysis using the Agilent Whole Rat Genome Oligo Microarray. Results. Hypertension induced 441 genes upregulated and 417 genes downregulated compared with the normal control group. Treatment of HJD resulted in 76 genes downregulated and 20 genes upregulated. GC data analysis showed that the majority of change genes were involved in immune system process, developmental process, and cell death. Conclusion. Hypertension altered expression of many genes that regulate various biological functions. HJD significantly reduced hypertension and altered the gene expression profiles of SHR rats. These changing genes were involved in many cellular functions such as regulating smooth muscle contraction, Ca(2+) homeostasis, and NO pathway. This study provides the potential novel insights into hypertension and antihypertension effects of HJD.