[Predictive value of sentinel lymph node biopsy in prognosis of acral melanoma]

Objective: To explore the application of sentinel lymph node biopsy (SLNB) and its prognostic value in the treatment of acral melanoma. Methods: We retrospective analyzed 118 patients who underwent sentinel lymph node biopsy from Mar 2012 to Jun 2019 with effective follow-up data available in our institute. We ruled out palpable regional lymph node metastasis with preoperative imaging of MRI and ultrasonography, used the (99)Tc(m)-Dextran (Dx) as a tracer, with intraoperative γ-ray probe positioning for SLN capture. Wide resection and reconstruction in primary lesion followed by complete lymph node dissection were underwent SLN positive patients. Cox regression model were used to analyze the prognostic factors. Results: The patients had an average disease history of 53.6 months (2-360 months), the primary lesion located at hands and feet in 84 cases, while 27 cases were subungual and 7 cases were cutaneous. The mean Breslow depth was 3.6 mm, and 72 cases (61.0%) combined with ulceration. The average number of SLN was 2.8, the SLN positive rate was 24.6% (29/118), and the false-negative rate was 2.5% (3/118). There were 24 cases (20.3%) developed clinically positive metastasis, including 7 cases displayed distant metastasis combined with lymph node metastasis (5.9%), 8 cases with clinically positive lymph node metastasis alone (6.8%), and 9 cases with distant metastasis (7.6%). There were 33 patients in stage Ⅰ, 56 patients in stage Ⅱ and 29 patients in stage Ⅲ, with a 5-years overall survival rate of 69.5%. The Breslow depth is an independent risk factor of SLN positive. While Breslow depth, SLN status, SLN positive number and clinically detectable metastasis are independent prognostic factors of the overall survival (P<0.05). Conclusions: Patients without clinically positive regional lymph node metastasis under imaging and physical examinations, SLNB can provide accurate pathologic staging and play an accurate prediction role in the prognostic evaluation. SLNB should be carried out routinely in clinical practice.

Enhanced high temperature ferromagnetism in Bi1-xRxFeO3(R= Dy, Y) compounds

In this work we report experimental evidence for the weak high-temperature ferromagnetism in Bi1-xRxFeO3(R= Dy, Y) compounds by systematic characterizations, excluding the possible side-effects from other iron-based impurities. Remarkable saturated magnetic moment was observed in the Y-substituted samples, Bi1-xYxFeO3, which is larger than the moment obtained in Bi1-xDyxFeO3, the Dy-substituted samples with antiferromagnetic background. The physical origin of the weak ferromagnetic transition is discussed and serious lattice distortions have been identified based on the x-ray diffraction and Raman scattering data, although the rhombohedral structure symmetry remains unchanged upon the substitutions. It is believed that the structural distortion suppressed cycloid spin structure is the main factor for the enhanced magnetization in Bi1-xRxFeO3compounds. Additionally, the Dy3+-Fe3+antiferromagnetic coupling, which strengthens the antiferromagnetic interaction in Bi1-xDyxFeO3compounds, acts as the driving force for the magnetic discrepancy between Bi1-xYxFeO3and Bi1-xDyxFeO3samples.

[Mutation analysis and prenatal diagnosis of MYO7A gene in a case of Usher syndrome type 1]

Objective: To analyze the clinical characteristics and identify the causative gene of a case with congenital deafness. Methods: Detailed medical history and clinical examination of a 4-year-old male child with congenital deafness were conducted in the First Affiliated Hospital of Army Military Medical University in June 2016. He was diagnosed with sensorineural deafness. The venous blood of the child and his parents was drawn, and genomic DNA was extracted. Proband's DNA was performed with targeted capture of high-throughput sequencing, then Sanger sequencing was used to verify the suspected mutation and segregation in this pedigree. According to the genetic diagnosis of the proband's deafness, ophthalmic examinations were performed. Genetic prenatal diagnosis was performed when the proband's mother was pregnant again. Results: The patient was detected with p.Trp1466Ter/p.Tyr2042Ter compound heterozygous mutations of MYO7A gene with targeted high-throughput sequencing. The mutation of p.Trp1466Ter was a reported mutation, while p.Tyr2042Ter has not been reported. In addition to congenital deafness, retinitis pigmentosa was also found by ophthalmologic examination, and the patient was clinically diagnosed with Usher syndrome type 1. Amniocentesis and fetal DNA sequencing were performed on the repregnancy fetus of this family at 18 weeks of gestation. The heterozygous mutation of MYO7A gene p.Tyr2042Ter was found, and the other allele was the wild type, indicating that the child will not exhibit clinical manifestations of Usher syndrome type 1. Indeed, the second child passed neonatal hearing screening. Conclusions: The clinical features and genetic variants were delineated in this family with Usher syndrome type 1. The results of the current study have enriched the phenotype and genotype data of the disease and provided a basis for genetic counseling.

Anaerobic digestion of microalgal biomass for bioenergy production, removal of nutrients and microcystin: current status

Using renewable microalgal biomass as active feedstocks for biofuels and bioproducts is explored to substitute petroleum-based fuels and chemicals. In the last few years, the importance of microalgae biomass has been realized as a renewable feedstock due to several positive attributes associated with it. Biorefinery via anaerobic digestion (AD) of microalgal biomass is a promising and sustainable method to produce value-added chemicals, edible products and biofuels. Microalgal biomass pretreatment is a significant process to enhance methane production by AD. Findings on the AD microbial community's variety and organization can give novel in turn on digester steadiness and presentation. This review presents a vital study of the existing facts on the AD microbial community and AD production. Co-digestion of microalgal biomass with different co-substrates was used in AD to enhance biogas production, and the process was economically viable with improved biodegradability. Microcystins, which are produced by toxic cyanobacterial blooms, create a severe hazard to environmental health. Anaerobic biodegradation is an effective method to degrade the microcystins and convert into nontoxic products. However, for the cost-effective conversion of biomass to energy and other beneficial byproducts, additional highly developed research is still required for large-scale AD of microalgal biomass.

Wnt antagonist secreted frizzled-related protein I (sFRP1) may be involved in the osteogenic differentiation of periodontal ligament cells in chronic apical periodontitis

AIM

To explore the mechanism of secreted frizzled-related protein I (sFRP1) involvement in the osteogenic differentiation of human periodontal ligament cells (hPDLCs) under inflammatory conditions.

METHODOLOGY

hPDLCs were cultured in an osteogenic differentiation-inducing medium (odi) and subjected to the stimulation of Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) with or without the inhibition of sFRP1. Quantitative real-time polymerase chain reaction, Western blot and enzyme-linked immunosorbent assay were carried out to evaluate the expression of osteogenic markers as well as the classic Wnt signalling pathway. Periapical periodontitis was induced in Wistar rats to further confirm the effect of sFRP1 inhibitor on bone loss in vivo. After the Shapiro-Wilk normality test, data were analysed by Student's paired t-test or one-way Anova test with a P value less than 0.05 as the level of statistical significance.

RESULTS

Significantly decreased mRNA and protein expression of osteogenic markers were detected in hPDLCs treated with P. gingivalis LPS during osteogenic induction (P < 0.001). Increased expression of sFRP1 was observed (P < 0.01), whilst Wnt/β-catenin signalling pathway was inhibited by the addition of P. gingivalis LPS (P < 0.01). After the addition of the sFRP1 inhibitor, the decrease of osteogenic markers (P < 0.05) and the inhibition of Wnt/β-catenin signalling pathway (P < 0.05) were reversed significantly. The animal experiment further confirmed that the sFRP1 inhibitor significantly reduced bone loss of periapical lesions in vivo (P < 0.0001).

CONCLUSIONS

Wnt antagonist sFRP1 was involved in the osteogenic differentiation of hPDLCs under inflammation. Modulation of the Wnt/β-catenin signalling pathway through the inhibition of sFRP1 may offer a new perspective on the treatment of chronic apical periodontitis.

[Effect of oral administration of branched-chain amino acids supplementation on the mortality of patients with hepatocellular carcinoma: a meta-analysis]

Objective: To investigate the effect of oral administration of branched-chain amino acids (BCAA) supplementation on the mortality of patients with hepatocellular carcinoma (HCC) after treatment. Methods: Computer searching of PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang, and Chinese Biomedical Literature Database was conducted to search for clinical controlled trials and randomized controlled trials (RCTs) on the effect of oral administration of BCAA on the mortality of patients with HCC. The retrieval time limit was from the time of the establishment of each database to December 30, 2019. Two researchers independently screened the literature and extracted the data. Another researcher assessed the risk of bias in the included studies and then used RevMan 5.3 software for meta-analysis. Results: A total of 14 studies were included with 1 179 patients. The overall results showed that oral administration of BCAA had no significant effect on the mortality of HCC patients at 1 year after treatment (RR=0.85, 95%CI:0.68-1.06, P=0.16), while the mortalities of patients at 3 years (RR=0.73, 95%CI: 0.61-0.88, P=0.000 7) and 5 years (RR=0.57, 95%CI:0.34-0.96, P=0.03) after treatment were significantly lower than those of the control group. The subgroup analysis showed that for radiofrequency ablation (RFA) patients, there was no significant difference in 1-year mortality between the BCAA group and the control group (RR=0.96, 95%CI:0.14-6.5, P=0.97), while 3-year mortality was significantly reduced (RR=0.59, 95%CI:0.43-0.81, P=0.001); for hepatectomy patients, there was no significant differences in 1 -and 3-year mortality between the two groups (RR=0.90, 95%CI:0.44-1.88, P=0.79; RR=0.97, 95%CI:0.71-1.33, P=0.85, respectively). In addition, as for albumin levels, BCAA supplementation significantly increased albumin levels without considering the treatment of HCC (SD=0.45, 95%CI: 0.29-0.90; P=0.000 1), but had no significant effect on hepatectomy patients (SD=0, 95%CI: -0.41-0.41, P=0.99). Conclusion: BCAA supplementation might improve liver reserve function and long-term prognosis of HCC patients, which was related to the surgical method. Supplementing BCAA reduced the long-term mortality of RFA patients, but had no significant effect on hepatectomy patients.

Influence of microcapsule parameters and initiator concentration on the self-healing capacity of resin-based dental composites

OBJECTIVE

Fracture is one of the main causes for failure of resin-based composite restorations. To overcome this drawback, self-healing resin-based composites have been designed by incorporation of microcapsules. However, the relationship between their self-healing capacity and microcapsule and resin parameters is still poorly understood. Therefore, the objective of this study was to systematically investigate the effect of initiator concentration (in the resin) and microcapsule size and concentration on the self-healing performance of commercially available flowable resin-based composites.

METHODS

Poly(urea-formaldehyde) (PUF) microcapsules containing acrylic healing liquid were synthesized in small (33±8μm), medium (68±21μm) and large sizes (198±43μm) and characterized. Subsequently, these microcapsules were incorporated into a conventional flowable resin-based composite (Majesty Flow ES2, Kuraray) at different contents (5-15wt%) and benzoyl peroxide (BPO) initiator concentrations (0.5-2.0wt%). Fracture toughness (K_IC) of test specimens was tested using a single edge V-notched beam method. Immediately after complete fracture (K_IC-initial), the two fractured parts were held together for 72h to allow for healing. Subsequently, fracture toughness of the healed resin-based composites (K_IC-healed) was tested as well.

RESULTS

The fracture toughness of healed dental composites significantly increased with increasing microcapsule size and concentration (2wt% BPO, p<0.05). The highest self-healing efficiencies (up to 76%) were obtained with microcapsules sized 198±43 um.

SIGNIFICANCE

commercially available resin-based composites can be rendered self-healing most efficiently by incorporation of large microcapsules (198±43μm). However, long-term tests on fatigue and wear behavior are needed to confirm the clinical efficacy.

[Active screening of intestinal carbapenem-resistant Enterobacteriaceae in high-risk patients admitted to the hematology wards and its effect evaluation]

Objective: To evaluate the effect of intestinal carbapenem-resistant Enterobacteriaceae (CRE) active screening combined with enhanced intervention in the prevention and control of nosocomial infection in patients admitted to the hematological ward. Methods: Patients who were admitted to the Department of Hematology in a tertiary-care general hospital from March 1, 2017 to December 31, 2019 and underwent chemotherapy or immunosuppressive therapy comprised the intervention group. They were screened for intestinal CRE at least thrice. From December 1, 2016 to February 28, 2017, patients who underwent chemotherapy or immunosuppressive therapy without active intestinal CRE screening in the Department of Hematology formed the control group. Both the patient groups were monitored for CRE infection in real time. The χ(2) test was used to compare the changes in the CRE infection rate and mortality in high-risk patients before and after the active screening. Results: During the intervention period, the CRE colonization rate of patients was 16.46% (66/401) ; in terms of disease distribution, the colonization rate of acute leukemia was the highest 23.03% (26/113) . Of the 66 colonized patients, 27 (40.9%) patients were identified as positive for CRE at the first screening, 15 (22.7%) were identified at the time of the second screening, and the remaining 24 (36.4%) were identified at the third or subsequent screening; Carbapenem-resistant Klebsiella pneumoniae (CRPK) strains were dominant among the pathogens, accounting for 54.55% (36/66) . During the active screening period, the CRE infection rate (2.49%) and mortality rate (50.00%) of high-risk patients were significantly lower than those of the controls (11.30% and 69.23%, respectively) . The pathogens of 10 CRE infection patients during the intervention period were exactly the same as the previous active screening pathogens, and the coincidence rate was 100%. Conclusion: The CRE colonization rate was the highest in patients with acute leukemia who were admitted in the hematology wards. CRPK is the main pathogen of CRE colonization, infection, and death. Increasing the frequency of screening can significantly raise the positive rate of screening, Active screening can effectively reduce the incidence and subsequent mortality of CRE in high-risk patients admitted in the hematological wards. High coincidence rate between CRE screening positive pathogens and subsequent CRE infection pathogens. Intestinal CRE screening can serve as an indicator of CRE bloodstream infection in patients with hematological diseases as well as provide information for antibiotics therapy.

Large Isospin Asymmetry in ^{22}Si/^{22}O Mirror Gamow-Teller Transitions Reveals the Halo Structure of ^{22}Al

β-delayed one-proton emissions of ^{22}Si, the lightest nucleus with an isospin projection T_{z}=-3, are studied with a silicon array surrounded by high-purity germanium detectors. Properties of β-decay branches and the reduced transition probabilities for the transitions to the low-lying states of ^{22}Al are determined. Compared to the mirror β decay of ^{22}O, the largest value of mirror asymmetry in low-lying states by far, with δ=209(96), is found in the transition to the first 1^{+} excited state. Shell-model calculation with isospin-nonconserving forces, including the T=1, J=2, 3 interaction related to the s_{1/2} orbit that introduces explicitly the isospin-symmetry breaking force and describes the loosely bound nature of the wave functions of the s_{1/2} orbit, can reproduce the observed data well and consistently explain the observation that a large δ value occurs for the first but not for the second 1^{+} excited state of ^{22}Al. Our results, while supporting the proton-halo structure in ^{22}Al, might provide another means to identify halo nuclei.

Thrombocytopenia as a preoperative risk assessment tool in patients with type B aortic dissection after thoracic endovascular aortic repair

Background

Postoperative thrombocytopenia has been reported to be correlated with adverse events, but the prognostic value of baseline thrombocytopenia is unclear. This study was undertaken to evaluate the relationship between preoperative thrombocytopenia and adverse outcomes in patients with type B aortic dissection who underwent thoracic endovascular aortic repair (TEVAR).

Methods

A total of 825 patients with acute and sub-acute type B aortic dissection undergoing were TEVAR at a multidisciplinary aortic center were enrolled between January 2010 and December 2017. Patients were stratified on the basis of presence (n=149) or absence (n=676) of thrombocytopenia (platelet count, &lt;150x109/L), according to preprocedural platelet counts. The primary outcome of interest was in-hospital mortality. Secondary outcomes of interest was long-term death.

Results

In the enrolled cohort, thrombocytopenia occurred in 149 (18.1%) patients. Patients with thrombocytopenia were older, were more commonly acute stage of TBAD, higher D-dimer level and had higher rates of abdominal vessel involvement and pericardial effusion. During the hospitalization period, 26 patients (3.2%) died, which was significantly higher in the thrombocytopenic group (8.1% versus 2.1%; P=0.001) Multivariate analyses revealed that thrombocytopenia was independently associated with in-hospital mortality (Table). During long-term follow-up (median duration 44.2 months), A total of 62 deaths were reported after discharge, including 40 (64.5%) aortic-related and unknown deaths, of which 12 and 50 patients for thrombocytopenia and non-thrombocytopenia group, respectively. Kaplan-Meier estimated rates of long-term all-cause mortality were higher for thrombocytopenia (log-rank test, P=0.014). Similar results were observed in a subset of aortic-related death (P=0.004) as well as aortic-related and unknown death (P=0.006), not non-aortic related death (P=0.878) (Figure 1).

Conclusion

Platelet counts, as simple and inexpensive indexes, were reliable to be used as a preoperative risk assessment tool for patients with type B aortic dissection undergoing thoracic endovascular aortic repair.

Figure 1. Long-term Mortality

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): This research was supported by grant DFJH201807 from High-level Hospital Construction Project of Guangdong Provincial People's Hospital.

Anal dysplasia as an incidental finding: the importance of specimen evaluation

AIM

The incidence of anal squamous cell carcinoma (SCC) has increased dramatically in the USA. The squamous intraepithelial lesion has been identified as a precursor lesion to SCC, stratifying the abnormality into low grade or high grade. There have been studies on the prevalence of incidentally found SCC in haemorrhoidectomy specimens, but there are no studies to date on the incidence of dysplasia. The purpose of this study was to establish a baseline incidence of dysplasia that provides helpful information for future epidemiological studies.

METHODS

This is a retrospective review of patients who underwent haemorrhoidectomy from 2005 to 2019. Pathology regarding the type of dysplasia, medications, and diagnoses that may predispose to immunosuppression were collected.

RESULTS

In all, 810 patients with a mean age of 51.7 (range 20-91) years underwent haemorrhoidectomy. Eighteen (2.2%) of the patients had abnormal pathology (low-grade squamous intraepithelial lesion, 3; high-grade squamous intraepithelial lesion, 12; SCC, 2; adenocarcinoma, 1). Thirty-seven (4.5%) of the entire cohort had some risk factors for immunosuppression: chronic steroid use (nine), human immunodeficiency virus (HIV) (13), biologic medications (six), transplant recipients (two) and immunocompromising diseases (four). Only 4/18 patients had an immunosuppression risk in that all four of these patients were HIV-positive. Surveillance following excision was undertaken for an average of 6 (range 1-12) months, during which time four patients underwent a repeat biopsy.

DISCUSSION

Anal dysplasia found in an otherwise asymptomatic population has a prevalence of 2.2%. This finding supports the routine examination of benign anorectal specimens undergoing microscopic examination. Interestingly, the majority of the patients identified had no immunosuppressant risk factors.

Risk stratification of ulcer-like projections in patients with acute type B aortic intramural hematoma

Background

Acute type B aortic intramural hematoma (IMH) with ulcer-like projections (ULP) is associated with various adverse aortic-related events (AAE) and recommended for preventive endovascular repair as alternative. However, we have no therapeutic criterion on which to decide preventive treatment.

Objectives

The purpose of this study was to determine the prognostic value and risk stratification of ULP in patients with acute type B IMH for proper treatment.

Methods

A retrospective study was conducted on 61 consecutive patients with acute type B IMH and with present of ULP from January 2015 to December 2018 in our center. All patients were treated medically initially and CT scans were performed on admission and during follow-up period.

Results

During a median follow-up of 4.5 months (range, 0.3 to 49.8 months) from onset, 36 patients (59.0%) had composites of adverse aortic events, including 1 patient died for aortic rupture, 6 patients converted to endovascular repair, 6 progressed into aortic dissection, and 28 developed to aortic enlargement. A cutoff value to estimate risk is 6.0 mm for maximal ULP width (72.2% sensitivity and 84.0% specificity) and 4.0 mm for maximal ULP depth (94.4% sensitivity and 52.0% specificity). Patients with widest (P=0.005) or deepest ULP (P=0.019) in aortic arch and proximal descending thoracic aorta had significant poorer aorta-related event-free survival rates. On multivariate analysis, maximal ULP width ≥6.0 mm [hazard ratio (HR) = 2.569, 95% confidence interval (CI):1.157 to 5.705, P=0.020], maximal ULP depth ≥4.0 mm (HR=5.198, 95% CI: 1.154 to 23.420, P=0.032) and widest ULP in aortic arch and proximal descending thoracic aorta (HR=2.363, 95% CI: 1.012 to 5.517, P=0.047) were independently associated with AAE. ULP with both risk location (widest ULP in aortic arch and proximal descending thoracic aorta) and size (maximal ULP width ≥6.0 mm) were significantly associated with a poorer aortic-related event-free survival rate than others (both P&lt;0.001).

Conclusions

Maximal ULP width ≥6.0 mm, maximal ULP depth ≥4.0 mm and widest ULP in aortic arch and proximal descending thoracic aorta are predictive for progression of acute type B aortic intramural hematoma. For patients with ULP in both risk location and size, preventive endovascular treatment should be considered.

Figure 1

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): This research was supported by grant DFJH201807 from High-level Hospital Construction Project of Guangdong Provincial People's Hospital.

Impact of timing on major complications after thoracic endovascular aortic repair for uncomplicated type B aortic dissection

Background

This study aimed to analyze the impact of the timing of intervention from presentation of symptoms to TEVAR and its relation to major complications for uncomplicated TBAD.

Methods

We retrospectively analyzed the data of 390 patients who underwent TEVAR for acute, subacute and chronic uncomplicated type B aortic dissection from January, 2010 to December 2017. Standard univariate and survival methods were used. The primary outcome of interest was in-hospital mortality. The Secondary outcomes of interest was long-term death and in-hospital adverse events, including postoperative coma, postoperative endoleak, postoperative stroke, postoperative spinal cord ischemia, postoperative limb ischemia, postoperative mesenteric ischemia/infraction.

Results

Of the 390 TEVARs for uncomplicated TBAD, 145 were performed within 14 days of presentation of symptoms (acute), 172 between 14 hours and 90 days (sub-acute), and 73 were beyond 90 days (chronic). Demographic characteristics were similar among groups (Table 1). A slight increase of in-hospital death, post-operative endoleak and limb ischemia, were observed in the acute intervention group compared with the sub-acute group (4.8% vs 2.3%, 11.7% vs 9.3%, 2.8% vs 2.3%, respectively). The chronic group patients had a highest rates of post-operative endoleak. However, there are no significantly differences between the three groups (Table 2). During long-term follow-up (median duration 36.9 months, interquartile range, 22.5–67.7 months), overall survival was similar among groups (log-rank test, P=0.280) (Figure).

Conclusion

TEVER performed for uncomplicated TBAD within 14 days to the presentation of symptoms, as compared with TEVAR between 14 hours and 90 days or beyond 90 days, neither appear to increase the risk of in-hospital complications nor long-term mortality.

Long-term All-cause Mortality

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): This research was supported by grant DFJH201807 from High-level Hospital Construction Project of Guangdong Provincial People's Hospital.

DGCR5 suppresses the EMT of pediatric primary glioblastoma multiforme cell and serves as a prognostic biomarker

OBJECTIVE

Pediatric primary glioblastoma multiforme (GBM) is a common brain tumor among childhood. Nevertheless, the underlying mechanism of glioblastoma progresses remains to be illuminated. The current study explores the potential functions of long noncoding RNA (lncRNA) DGCR5 in the aggressiveness of GBM.

PATIENTS AND METHODS

The expression of DGCR5 was evaluated by quantitative real-time PCR (qRT-PCR). Immunoblotting was carried out to assess the protein expressions of N-cadherin and E-cadherin. Cell Counting Kit-8 (CCK-8), wound healing, transwell assay, and flow cytometry were applied to explore the roles of DGCR5 in glioblastoma cell malignant biological behaviors.

RESULTS

LncRNA DGCR5 was down expressed in glioblastoma. Transfection of DGCR5 markedly repressed cell viability and colony formation ability of U87 and U251 cells. Additional, DGCR5 overexpression caused cell cycle arrest and increased cell apoptosis. Moreover, upregulation of DGCR5 suppressed the growth and promoted cell apoptosis of U87 cell in vivo. Finally, overexpression of DGCR5 impaired the migration, invasiveness, and reversed epithelial-to-mesenchymal transition (EMT) process of glioblastoma cell.

CONCLUSIONS

LncRNA DGCR5 inhibited the proliferation, aggressiveness phenotypes, and EMT of glioblastoma cell.

Structure of a two-dimensional superparamagnetic system in a quadratic trap

Ground-state structures of a two-dimensional (2D) system composed of superparamagnetic charged particles are investigated by means of molecular dynamics simulation. The charged particles trapped in a quadratic potential interact with each other via the repulsive, attractive, and magnetic dipole-dipole forces. Simulations are performed within two regimes: a one-component system and a two-component system where the charged particles have the identical charge-to-mass ratio. The effects of magnetic dipole-dipole interaction, mixing ratio of the two species and confinement frequency on the ground-state structures are discussed. It is found that as the strength of the magnetic dipole increases, the charged particles tend to self-organize into chainlike structures. The two species particles exhibit different structural features, depending on the competition of electrostatic repulsive interaction, magnetic dipole-dipole interaction and confinement force. The potential lanes are observed through analyzing the global potential of the magnetic particles, which guide the unmagnetic particles aligning themselves in the direction of the potential lanes.

Non-ohmic conduction in sodium bismuth titanate: the influence of oxide-ion conduction

A nominal Bi-excess starting composition of sodium bismuth titanate, Na0.5Bi0.51TiO3.015 (NB0.51T) produces dielectric ceramics that exhibit mixed n-type and oxide-ion conductivity with an ionic transport number of ∼0.1 at ≥600 °C. The bulk electrical conductivity, σb, of NB0.51T ceramics under a dc bias field of ≤100 V cm-1 has been investigated by impedance spectroscopy. Over the temperature range ∼550 to 750 °C, σb increases by up to one order of magnitude under the dc bias and returns to its initial value on removal of the bias. The enhancement of conductivity is dependent on temperature, atmosphere, dc bias field and the electrode materials. A maximum conductivity enhancement of >2000% is achieved at 600 °C in nitrogen using Pt electrodes. This is in contrast to that observed for other n-type perovskite titanates and oxygen-deficient rutile where σb is suppressed under a dc bias. This 'unusual' non-ohmic behaviour is attributed mainly to the influence of highly mobile oxygen vacancies in NB0.51T. The field-enhanced σb is best described to be a consequence of increased pumping of oxygen from the cathode to the anode, in which the electrode reactions play an important role. In addition, dissociation of defect clusters may also contribute to the enhanced σb under a dc bias. The high, fast and reversible response to the dc bias voltage may expand the potential application of NBT-based materials to memory devices.

3-n-butylphthalide inhibits the apoptosis of nerve cells in rats with cerebral small vessel disease via the PI3K/Akt pathway

OBJECTIVE

The aim of this study was to investigate the effect of 3-n-butylphthalide (NBP) on the apoptosis of nerve cells in vascular dementia (VaD) model rats caused by cerebral small vessel disease (CSVD), and to explore its regulatory mechanism.

MATERIALS AND METHODS

The model of VaD was successfully established in rats by carotid artery ligation. All rats were randomly divided into three groups, including the sham operation group, model group and NBP group. The neurobehavioral score was used to verify whether the model was successfully established. The changes in learning and memory abilities of rats were detected via water maze experiment. The levels of Bcl-2-associated X protein (Bax) and cysteinyl aspartate specific proteinase-3 (Caspase-3) in the serum of rats was detected by enzyme-linked immunosorbent assay (ELISA). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay was adopted to detect the apoptosis of nerve cells in brain tissues of rats. Moreover, the protein levels of phosphorylated phosphatidylinositol-3-kinase (PI3K) and phosphorylated protein kinase B (Akt) in brain tissues of rats were measured using Western blotting.

RESULTS

Compared with the sham operation group, the neurobehavioral score of rats increased significantly, whereas learning and memory abilities decreased markedly in the model group. The levels of Bax and Caspase-3 in rat serum were remarkably up-regulated, and the apoptosis rate of nerve cells in brain tissues of rats increased significantly in the model group as well. Meanwhile, the levels of phosphorylated PI3K and phosphorylated Akt were notably declined. Compared with the model group, the neurobehavioral score decreased markedly, while learning and memory abilities were remarkably improved in the NBP group. The levels of Bax and Caspase-3 in rat serum were significantly down-regulated, and the apoptosis rate of nerve cells in brain tissues of rats were reduced in the NBP group. Furthermore, the protein levels of phosphorylated PI3K and phosphorylated Akt were remarkably elevated in the NBP group.

CONCLUSIONS

NBP can improve the morphology of brain tissue cells and the learning and memory abilities, and inhibit the apoptosis of nerve cells in VaD model rats with CSVD. The possible underlying mechanism may be related to the activation of the PI3K/Akt signaling pathway.

The efficacy of simendan in the treatment of acute heart failure and its impact on NT-proBNP

OBJECTIVE

Simendan is a calcium sensitizer that enhances myocardial contractility but does not affect ventricular diastole. Simendan also has a vasodilatation effect, which causes coronary artery resistance and venous volume blood vessel relax, thereby improving coronary blood supply. This study adopted simendan on the basis of conventional anti-heart failure treatment to explore a new approach for the treatment of heart failure.

PATIENTS AND METHODS

Eighty patients with heart failure were randomly and equally divided into an observation group and control group according to the digital table method. The control group was given a conventional anti-heart failure treatment. The observation group was treated with simendan on the basis of the control group. The left ventricular ejection fraction (LEVF), stroke volume (SV), NT-proBNP, K+, and Ca2+ were measured before and after the treatment. The clinical efficacy and adverse reactions after treatment were compared. The 6-minute walking distance (6MWT) was recorded on the 60th day after treatment.

RESULTS

There were no significant differences in LVEF and SV between the two groups before the treatment. They were significantly increased after treatment and were significantly higher in the observation group than that in the control group (p < 0.05). The total effective rate in the observation group (92.50%) was significantly higher than that in the control group (67.50%). There was no statistical difference in the occurrence of adverse reactions between the two groups (p > 0.05). The 6MWT in the observation group was 452.63±86.51 meters, which was significantly higher than that in the control group (366.85±70.46 meters) (p < 0.05). There was no significant difference in plasma NT-proBNP levels between the two groups (p > 0.05). The plasma NT-proBNP level was significantly lower in the observation group than that in the control group after treatment (p < 0.05). Serum K+ and Ca2+ were not significantly changed after treatment in the control group (p > 0.05). Serum K+, but not Ca2+, was significantly elevated in the observation group.

CONCLUSIONS

Simendan can significantly reduce plasma NT-proBNP level; thus, it is relatively safe and effective for the treatment of acute heart failure (AHF).