A novel Al matrix composite reinforced by nano-AlNp network

In pursuit of lightweighting of automobiles and low emission of transportation, the efforts to develop high-strength, heat-resistant and fatigue-resistant Al alloys and/or composites have been ongoing. Here we report a novel Al matrix composite with ultrahigh strength reinforced by a three dimensional network of nano-AlN particles for the first time. The in-situ synthesized AlN particles are connected by twinning bonding chains and built up a three dimensional network strengthening Al matrix enormously like the skeleton to human body. The composite containing 16.4wt.% AlN particles shows excellent properties: the ultimate tensile strengths can be up to 518MPa at room temperature and 190MPa at 350 °C. This peculiar performance results from the novel spatial distribution of nano-scale AlN particles. Our findings in this work would help to develop a potential candidate for high-performance heat resistance light-metal based materials.

Clinical efficacy of modified partial pars plana vitrectomy combined with phacoemulsification for malignant glaucoma

ObjectiveThe objective of this study was to evaluate the clinical effects of modified partial pars plana vitrectomy together with phacoemulsification, intraocular lens (IOL) implantation, posterior capsulectomy, and zonulohyaloidectomy for patients with malignant glaucoma after trabeculectomy or cataract surgery.DesignRetrospective, cohort study.ParticipantsThirty consecutive patients (30 eyes) with malignant glaucoma after trabeculectomy surgery or ultrasonic phacoemulsification of cataract between January 2008 and September 2014 were enrolled.MethodsA retrospective analysis of 30 eyes with malignant glaucoma after trabeculectomy surgery for angle-closure glaucoma or ultrasonic phacoemulsification of cataract was performed. All patients underwent modified partial pars plana vitrectomy with zonulohyaloidectomy. Phacoemulsification and IOL implantation was performed in 25 patients with no previous cataract surgery. Pre-operative and post-operative ocular parameters were recorded in detail.Main outcome measuresClinical features, anterior chamber depth, best-corrected visual acuity, and intraocular pressure (IOP).ResultsIn these 30 patients, 25 had undergone trabeculectomy surgery and 5 had undergone cataract surgery. The mean axial length was 21.3±0.8 mm. After surgery, mean IOP decreased from 34±8.3 mm Hg to 10.5±4.1 mm Hg (P<0.001), and mean anterior chamber depth increased from 0.8±0.4 mm to 2.7±0.3 mm (P<0.001). No severe complications occurred.ConclusionsModified partial pars plana vitrectomy combined with phacoemulsification, IOL implantation, posterior capsulectomy, and zonulohyaloidectomy not only simplifies the process of traditional vitrectomy, but effectively resolves the ciliary block and corrects the misdirection of aqueous humor in malignant glaucoma.

Breastfeeding modifies the effects of environment tobacco smoke exposure on respiratory diseases and symptoms in Chinese children: the Seven Northeast Cities Study

To evaluate the potential effect of interaction between breastfeeding and environmental tobacco smoke (ETS) exposure on respiratory health, we studied 31 049 children (aged 2-14 years) from 25 districts of seven cities in northeast China. Parents of the children completed standardized questionnaires that characterized the children's histories of respiratory symptoms and illness, feeding methods, ETS exposure, and other associated risk factors. Breastfeeding was defined as having been mainly breastfed for 3 months or more. The results showed that the association of ETS exposure with childhood respiratory conditions/diseases was modified by breastfeeding, and the association for nonbreastfed children was stronger than that for breastfed children. In particular, for nonbreastfed children, the odds ratios (ORs) for the effect of current ETS exposure asthma was 1.71 (95% CI: 1.43-2.05); however, the OR for breastfed children was 1.33 (95% CI: 1.20-1.48), indicating that the interactions between breastfeeding and current ETS exposure on asthma were statistically significant (P = 0.019). When stratified by school (kindergarten vs. elementary school), breastfeeding was more protective for asthma-related symptoms among children from kindergarten. In conclusion, this study shows that breastfeeding is associated with smaller associations between ETS exposure and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of ETS.

HSP90 gene expression induced by aspirin is associated with damage remission in a chicken myocardial cell culture exposed to heat stress

To understand the potential protection of heat shock protein 90 (HSP90) induced by aspirin against heat stress damage in chicken myocardial cells, enzyme activities related to stress damage, cytopathological changes, the expression and distribution of HSP90, and HSP90 mRNA levels in the myocardial cells exposed to heat stress (42°C) for different durations with or without aspirin administration (1 mg/ml, 2 h prior) in vitro were investigated. Significant increase of enzyme levels in the supernatant of heat-stressed myocardial cells and cellular lesions characterised by acute degeneration, karyopyknosis and karyorrhexis were observed, compared to non-treated cells. However, the lesions of cells treated with aspirin were milder, characterised by earlier recovery of enzyme levels to the control levels and no obvious heat stress-related cellular necrosis. Stronger positive signals in the cytoplasm and longer retention of HSP90 signal in nuclei were observed in aspirin-treated myocardial cells than those of only heat-stressed cells. HSP90 level in the aspirin-treated myocardial cells was 11.1-fold higher than that in non-treated cells, and remained at a high level at the early stage of heat stress, whereas it was just 4.1-fold higher in only heat-stressed cells and returned rapidly to a low level. Overexpression of HSP90 mRNA in aspirin-treated cells was observed throughout the experiment, whereas HSP90 mRNA decreased significantly only in heat-stressed cells. The early higher HSP90 expression induced by aspirin during heat stress was accompanied by decreased heat stress damage, suggesting that aspirin might play an important role in preventing myocardial cells from heat stress damage in vitro.

Mutations of glucocerebrosidase gene and susceptibility to Parkinson's disease: An updated meta-analysis in a European population

This meta-analysis aims to investigate the association between mutations of glucocerebrosidase (GBA) gene and susceptibility to Parkinson's disease (PD) in a European population. Several electronic databases were extensively searched. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association. In total, fourteen published papers screening L444P, N370S and other GBA variants were identified. The GBA mutations were significantly associated with PD in the European population. Subgroup analysis stratified by the age of onset (AAO) revealed that the association between GBA mutations and PD existed in the patients with age at onset ⩽50 years but did not exist in the patients with age at onset >50 years. Furthermore, the associations between N370S, and L444P with PD were also analyzed to explore the roles of the two most frequent GBA mutations in the development of PD. The results showed that significant associations between N370S, and L444P with PD were observed, respectively. Overall, the study supported that GBA mutations were a risk factor for PD in the European population. Patients with early-onset were more likely to carry GBA mutations than those with late-onset. Moreover, both L444P and N370S were associated with increased PD risk.

Expression of macrophage migration-inhibitory factor in duodenal ulcer and its relation to Helicobacter pylori infection

The aim of this study was to examine the expression of macrophage migration-inhibitory factor (MIF) in duodenal ulcer epithelial cells and its relation to Helicobacter pylori (Hp) infection, and to discuss the pathogenic roles of MIF expression and Hp infection in duodenal ulcer. MIF protein and mRNA expression was examined in samples from patients with duodenal ulcer with and without Hp infection (N = 40 each, experimental group), and in normal duodenal bulb mucosal tissue (N = 40, control group) using immunohistochemistry and in situ hybridization. Patients without Hp infection received routine treatment, and treatment was provided to the patients positive for Hp to eradicate Hp infection. Hp and MIF expression levels before treatment and after the ulcer had been cured were compared. The positive rates of MIF protein and mRNA in patients with Hp infection before treatment were 67.5 and 65%, respectively, and were 18.9 and 21.6% in the 37 patients from whom Hp was eliminated. These were statistically different both before and after treatment compared with controls (P < 0.05). In the patients without Hp infection, the positive rates of MIF protein and mRNA expression before (45 and 47.5%, respectively) and after (32.5 and 30%) treatment were not significantly different (P > 0.05). The results of this study suggested that MIF is related to the development of duodenal ulcer, and that the presence of Hp is closely related with the expression of MIF in the duodenal mucosa and the development of duodenal ulcer.

Effect of hemodynamics on the recurrence of posterior communicating artery aneurysm: a computational fluid dynamics simulation study

AIM

To compare the hemodynamic characteristics of posterior communicating artery aneurysm before and after embolization and investigate its relationship with aneurysm recurrence using a computational fluid dynamics simulation study.

METHODS

Thirteen patients undergone embolization of posterior communicating artery aneurysm between January 2008 and February 2010 were enrolled and divided into recurrent and recovered group according to their follow-up angiographic data. Aneurysm models were established using three-dimensional cerebral angiography data collected before and after embolization. Preoperative and postoperative hemodynamic modalities at aneurysm neck region were analyzed with computational fluid dynamics software using the finite element algorithm. In this study, computational models were set according to transcranial Doppler pulsatile flow, and the part of aneurysm occluded by spring coil is completely independent of the blood flow.

RESULTS

In recurrent group, peak systolic wall shear stress and blood flow velocity at the aneurysm neck region were significant increased after the embolization. On the contrary, in recovered group peak systolic wall shear stress and blood flow velocity were significantly reduced after the embolization. The recurrent group also had higher post-embolization peak systolic wall shear stress and blood flow velocity than the recovered group.

CONCLUSION

High wall shear stress and blood flow velocity after embolization at the neck region of posterior communicating artery aneurysm may promote early aneurysm recurrence.

Environmental tobacco smoke exposure, urine CC-16 levels, and asthma outcomes among Chinese children

BACKGROUND

Previous studies have shown the relationship between club cell secretory protein (Clara) (CC-16) and respiratory diseases. However, few studies have explored the associations between urine CC-16 levels and environmental tobacco smoke (ETS) exposure in children. The objective of this study was to evaluate whether ETS exposure is associated with CC-16 when stratified by asthma status.

METHODS

In our study, CC-16 was measured on 537 children aged 9-15 from northeast China in 2011-2012 using the Human Clara Cell Protein ELISA kits. Doctor-diagnosed asthma was defined as having ever been diagnosed with asthma by a physician. The relationship between ETS exposure and urine CC-16 level was assessed using linear regression.

RESULTS

When stratified by asthma status, a negative association between ETS exposure and urine CC-16 was observed after adjusting for the effects of the related covariates, with an adjusted β coefficient [P value] = -0.31 [0.006] in the first 2 years of life and with an adjusted β coefficient [P value] = -0.68 [0.004] in the first 2 years of life and current.

CONCLUSIONS

Our study shows long-term exposure to ETS was associated with urinary CC-16 among children without asthma.

Energy-partition diagnostic for measuring time-resolved scattering and absorption in burst-mode laser ablation

We describe an energy-partition diagnostic based on integrating sphere principle for measuring absorption and scattering in plasma-mediated ablation by a high repetition-rate (133 MHz), pulsetrain-burst ultrafast-pulse laser. The system time-resolves the partition of elastically scattered laser light into specular reflection, diffuse reflection, and transmission, giving access to per-pulse absorption dynamics. Physical events such as optical breakdown and incubation effects in glass and aluminum are illustrated.

HER2, MET and FGFR2 oncogenic driver alterations define distinct molecular segments for targeted therapies in gastric carcinoma

Background:

Gastric cancer (GC) is a leading cause of cancer deaths worldwide. Since the approval of trastuzumab, targeted therapies are emerging as promising treatment options for the disease. This study aimed to explore the molecular segmentation of several known therapeutics targets, human epidermal growth factor receptor 2 (HER2), MET and fibroblast growth factor receptor 2 (FGFR2), within GC using clinically approved or investigational kits and scoring criteria. Knowledge of how these markers are segmented in the same cohort of GC patients could improve future clinical trial designs.

Methods:

Using immunohistochemistry (IHC) and FISH methods, overexpression and amplification of HER2, FGFR2 and MET were profiled in a cohort of Chinese GC samples. The correlations between anti-tumour sensitivity and the molecular segments of HER2, MET and FGFR2 alterations were further tested in a panel of GC cell lines and the patient-derived GC xenograft (PDGCX) model using the targeted inhibitors.

Results:

Of 172 GC patients, positivity for HER2, MET and FGFR2 alternations was found in 23 (13.4%), 21 (12.2%) and 9 (5.2%) patients, respectively. Positivity for MET was found in 3 of 23 HER2-positive GC patients. Co-positivity for FGFR2 and MET was found in 1 GC patient, and amplification of the two genes was found in different tumour cells. Our study in a panel of GC cell lines showed that in most cell lines, amplification or high expression of a particular molecular marker was mutually exclusive and in vitro sensitivity to the targeted agents lapatinib, PD173074 and crizotinib was only observed in cell lines with the corresponding high expression of the drugs' target protein. SGC031, an MET-positive PDGCX mouse model, responded to crizotinib but not to lapatinib or PD173074.

Conclusions:

Human epidermal growth factor receptor 2, MET and FGFR2 oncogenic driver alterations (gene amplification and overexpression) occur in three largely distinct molecular segments in GC. A significant proportion of HER2-negative patients may potentially benefit from MET- or FGFR2-targeted therapies.

Magnetoelastic vibrational biomaterials for real-time monitoring and modulation of the host response

Magnetoelastic (ME) biomaterials are ferromagnetic materials that physically deform when exposed to a magnetic field. This work describes the real-time control and monitoring capabilities of ME biomaterials in wound healing. Studies were conducted to demonstrate the capacity of the materials to monitor changes in protein adsorption and matrix stiffness. In vitro experiments demonstrated that ME biomaterials can monitor cell adhesion and growth in real-time, and a long-term in vivo study demonstrated their ability to monitor the host response (wound healing) to an implant and control local cell density and collagen matrix production at the soft tissue-implant interface. This approach represents a potentially self-aware and post-deployment activated biomaterial coating as a means to monitor an implant surface and provide an adjuvant therapy for implant fibrosis.

Does footprint depth correlate with foot motion and pressure?

Footprints are the most direct source of evidence about locomotor biomechanics in extinct vertebrates. One of the principal suppositions underpinning biomechanical inferences is that footprint geometry correlates with dynamic foot pressure, which, in turn, is linked with overall limb motion of the trackmaker. In this study, we perform the first quantitative test of this long-standing assumption, using topological statistical analysis of plantar pressures and experimental and computer-simulated footprints. In computer-simulated footprints, the relative distribution of depth differed from the distribution of both peak and pressure impulse in all simulations. Analysis of footprint samples with common loading inputs and similar depths reveals that only shallow footprints lack significant topological differences between depth and pressure distributions. Topological comparison of plantar pressures and experimental beach footprints demonstrates that geometry is highly dependent on overall print depth; deeper footprints are characterized by greater relative forefoot, and particularly toe, depth than shallow footprints. The highlighted difference between 'shallow' and 'deep' footprints clearly emphasizes the need to understand variation in foot mechanics across different degrees of substrate compliance. Overall, our results indicate that extreme caution is required when applying the 'depth equals pressure' paradigm to hominin footprints, and by extension, those of other extant and extinct tetrapods.

In vitro chemosensitivity assay of ascites in epithelial ovarian cancer

OBJECTIVE

This study aimed to investigate the predictive value of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for chemosensitivity test in ascites.

MATERIALS AND METHODS

The relationship of the in vitro sensitivity results and the clinicopathological characteristics, objective response rates (ORRs) of chemotherapy, and time to progression (TTP) were retrospectively analyzed in 120 epithelial ovarian cancer (EOC) patients. The clinical response criterion was based on the Response Evaluation Criteria in Solid Tumors (RECIST) standard. The log-rank test and Kaplan-Meier curve were used to estimate TTP.

RESULTS

MTT assays revealed that tumor cells from ascites of primary and type II EOC were more sensitive to paclitaxel (PTX) and carboplatin (CBDCA) than relapse (p = 0.01 and p < 0.01, respectively) and type I (p = 0.03, p = 0.02, respectively) EOC. p53 positive expression and Ki67 high expression were associated with high PTX (p = 0.01 and p < 0.01, respectively) and CBDCA (p = 0.03 and p < 0.01, respectively) sensitivity. Ki67 weak positive immunostaining was associated with topotecan (p < 0.01), gemcitabine (p < 0.01), and doxorubicin (p < 0.01) resistance. Chemosensitivity to CBDCA/PTX was associated with the ORR ofneo-adjuvant (p = 0.03) and adjuvant (p = 0.02) chemotherapy. The MTT assay results of ascites were consistent with the clinical response (p = 0.04) and TTP (p = 0.04) in patients with platinum-resistant relapse EOC tumors.

CONCLUSIONS

Evaluation of the chemosensitivity of ascites in EOC by MTT can aid the establishment of individualized clinical chemotherapeutic plans for platinum-resistant relapse patients.

Thermosensitive polymeric hydrogels as drug delivery systems

Thermosensitive hydrogels are very important biomaterials used in drug delivery systems (DDSs), which gained increasing attention of researchers. Thermosensitive hydrogels have great potential in various applications, such as drug delivery, cell encapsulation, tissue engineering, and etc. Especially, injectable thermosensitive hydrogels with lower sol-gel transition temperature around physiological temperature have been extensively studied. By in vivo injection, the hydrogels formed non-flowing gel at body temperature. Upon incorporation of pharmaceutical agents, the hydrogel systems could act as sustained drug release depot in situ. Injectable thermosensitive hydrogel systems have a number of advantages, including simplicity of drug formulation, protective environment for drugs, prolonged and localized drug delivery, and ease of application. The objective of this review is to summarize fundamentals, applications, and recent advances of injectable thermosensitive hydrogel as DDSs, including chitosan and related derivatives, poly(N-isopropylacrylamide)-based (PNIPAAM) copolymers, poly(ethylene oxide)/poly(propylene oxide) (PEO/PPO) copolymers and its derivatives, and poly(ethylene glycol)/ biodegradable polyester copolymers.