Octadecylamine-Grafted Graphene Oxide Helps the Dispersion of Carbon Nanotubes in Ethylene Vinyl Acetate

In this paper, the dispersion of carbon nanotube (CNT) in ethylene vinyl acetate (EVA) is demonstrated to be significantly improved by the addition of octadecylamine (ODA)-grafted graphene oxide (GO) (GO–ODA). Compared to the CNT/EVA composite, the resultant GO–ODA/CNT/EVA (G–CNT/EVA) composite shows simultaneous increases in tensile strength, Young’s modulus and elongation at break. Notably, the elongation at break of the G–CNT/EVA composite still maintains a relatively high value of 1268% at 2.0 wt % CNT content, which is more than 1.6 times higher than that of CNT/EVA composite (783%). This should be attributed to the homogeneous dispersion of CNT as well as the strong interfacial interaction between CNT and EVA originating from the solubilization effect of GO–ODA. Additionally, the G–CNT/EVA composites exhibit superior electrical conductivity at low CNT contents but inferior value at high CNT contents, compared to that for the CNT/EVA composite, which depends on the balance of CNT dispersion and the preservation of insulating GO–ODA. Our strategy provides a new pathway to prepare high performance polymer composites with well-dispersed CNT.

Improvement in orthopedic outcome score and reduction in IL-1β, CXCL13, and TNF-α in synovial fluid of osteoarthritis patients following arthroscopic knee surgery

Knee osteoarthritis (KOA) is a common degenerative joint disease and immune system dysregulation has been implicated in its pathogenesis. The effect of arthroscopic knee surgery, an important method for KOA diagnosis and treatment, on the expression of immune regulators remains poorly understood. We aimed to investigate the clinical efficacy of such surgery and its impact on IL-1β, CXCL13, and TNF-α expression in the knee joint synovial fluid of osteoarthritis patients. Fifty-seven patients having undergone arthroscopic knee surgery in our hospital were included. Visual analog scale (VAS) and Lysholm scores were recorded before surgery, and knee joint synovial fluid was collected during the procedure. According to Outerbridge cartilage damage score (grade 0, 1, 2, 3, or 4), patients were divided into five groups. In addition, VAS and Lysholm scores were recorded and knee joint synovial fluid was collected after a six-month follow-up period. Expression of IL-1β, CXCL13, and TNF-α in synovial fluid samples was then measured. In each group, levels of these molecules and VAS and Lysholm scores were significantly lower after surgery (P < 0.05). IL-1β, CXCL13, and TNF-α levels were significantly elevated in patients with higher cartilage damage scores compared to those with lower scores. Arthroscopic knee surgery can reduce IL-1β, CXCL13, and TNF-α levels in the knee joint synovial fluid of osteoarthritis patients. Moreover, reduced presence of these molecules correlates with clinical improvement of this condition. Therefore, reduction in IL-1β, CXCL13, and TNF-α expression might be used as a factor for long-term osteoarthritis prognosis.

Interfacial Shish-Kebabs Lengthened by Coupling Effect of In Situ Flexible Nanofibrils and Intense Shear Flow: Achieving Hierarchy To Conquer the Conflicts between Strength and Toughness of Polylactide

The challenge of hitherto elaborating a feasible pathway to overcome the conflicts between strength and toughness of polylactide (PLA) still remains among academia and industry. In the current work, a unique hierarchal structure of flexible poly(butylene adipate-co-terephthalate) (PBAT) in situ nanofibrils integrating with abundant PLA shish-kebabs as a strong building block was disclosed and expresses its capability to conquer this dilemma. Substantially simultaneous enhancement on tensile strength, impact strength, and elongation at break could be achieved up to 91.2 MPa, 14.9 KJ/m², and 15.7%, respectively, compared with pure PLA (61.5 MPa, 4.3 KJ/m², and 6.2%). Through investigating the phase (and crystalline) morphology and molecular chain behavior in the PLA/PBAT system, the formation mechanism of this structure facilitated by a coupling effect of PBAT flexible phase and shear flow was definitely elucidated. The dispersed phase of PBAT would be more inclined to existing as a fibrillar form within the PLA matrix benefiting from low interfacial tension. Interestingly, this phase morphology with large specific surface area changes the crystallization behavior of PLA significantly, once introducing an intense shear flow (∼10³ s^-1), in situ shear-formed nanofibrils of PBAT would show strong coupling effect with shear flow on PLA crystallization: they can not only induce abundant shish-kebabs of PLA at its interfaces, which possesses lengthened shish and more densely arranged kebabs, but also further retard the relaxation of PLA chains through hysteretic relaxation of its PBAT phase, which can effectively prevent the collapse of established shish. Of immense significance is this particular hierarchical-architecture composed by flexible nanofibers (PBAT) and rigid shish-kebabs (PLA), which provides significant guidance for the simultaneous reinforcement and toughness of polymer materials.

Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk

Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders’ spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the “rigid−soft” system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight.

[Analysis of clinical and pathological characteristics of high- risk HPV-negative carcinoma of the uterine cervix]

Objective: To study the clinical and pathological characteristics of HPV-negative cervical cancer patients. Methods: Retrospective analysis of 785 cervical cancer patients in Guangdong Women and Children Hospital from Jan. 2005 to Oct. 2015. By detecting high- risk HPV infection by flow-through hybridization genechip technique. Results: (1)Among 785 cases of cervical cancer, 71 cases were negative for HPV infection tested by genechip technique, accounting for 9.0%(71/785), and the relative light units/cut off(RLU/CO)ratios of these 71 cases were less than 1 by hybird capture Ⅱ(HC-Ⅱ)methods. The results showed that the positive coincident rate of genechip technique detecting result with HC-Ⅱ method was 100.0%(71/71).(2)There was no difference between 43(60.6%)cases from 41-55 years old of 71 cases of HPV-negative patients and 392(54.9%)cases from 41- 55 years old of 714 cases of HPV infection patients(χ²=15.63, P=0.571). Among 71 cases of HPV-negative patients, 32 cases of patients with doing TCT, 6(18.8%)cases for normal, 10(31.2%)cases for atypical squamous cells of undetermined significance(ASCUS), 3(9.4%)cases for atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion(ASC-H), 3(9.4%)cases for low-grade squamous intraepithelial lesions(LSIL), 8(25.0%)cases for hight-grade squamous intraepithelial lesions(HSIL), 2(6.2%)cases for squamous cell carcinoma(SCC). And there were 391 cases of patients with doing thin-prep cytologic test(TCT)of 714 HPV infection patients, 60(15.3%)cases for normal, 61(15.6%)cases for ASCUS, 28(7.2%)cases for ASC-H, 29(7.4%)cases for LSIL, 164(41.9%)cases for HSIL, 49(12.5%)cases for SCC. There was no difference of TCT between HPV infection and HPV-negative patients(P>0.05). Among 70 cases from 71 patients with negative for HPV infection, there were 8(11.4%)cases in stage Ⅰ a, 26(37.1%)cases in stage Ⅰ b1, 12(17.1%)cases in stage Ⅰb2, 11(15.7%)cases in stage Ⅱa, 10(14.3%)cases in stage Ⅱb, 3(4.3%)cases in stage Ⅲ-Ⅳ. There were 118(16.6%)cases in stage Ⅰa, 261(36.8%)cases in stage Ⅰb1, 72(10.1%)cases in stage Ⅰb2, 152(21.4%)cases in stage Ⅱa, 87(12.3%)cases in stage Ⅱb, 20(2.8%)cases in stage Ⅲ-Ⅳ in 710 cases of HPV infection patients, in which there were no difference of clinical stage between HPV infection and HPV-negative patients(P>0.05). Among 69 cases from 71 patients HPV-negative infection, there were 51(73.9%)cases for squamous carcinoma, 13(18.8%)cases for adenocarcinoma, 5(7.2%)cases for adenosquamous carcinoma; and 593(87.2%)cases for squamous carcinoma, 38(5.6%)cases for adenocarcinoma, 39(5.7%)cases for adenosquamous carcinoma, 10(1.5%)case for others were in 680 patients of HPV infection, in which there was significant difference of adenocarcinoma between HPV infection and HPV-negative patients(χ²=11.96, P=0.001). Conclusions: Flow-through hybridization genechip technique is the method of high sensitivity to detect high-risk type HPV, as like HC-Ⅱ method. HPV-negative of cervical cancer occurs mainly in 41- 55 years old. Adenocarcinoma incidence is significantly higher in HPV-negative cases than those patients with infection of HPV positive.

[Treatment of advanced Siewert type Ⅱ esophagogastric junction adenocarcinoma by thoracoabdominal radical gastrectomy and D2 lymphadenectomy]

OBJECTIVE

To investigate the advantages of thoracoabdominal radical gastrectomy for advanced Siewert type Ⅱ adenocarcinoma of the esophagogastric junction.

METHODS

Clinical data of 86 patients with Siewert type Ⅱ adennocarcinoma of the esophagogastric junction who received surgical treatment at the Henan Provincial Tumor Hospital from January 2015 to January 2016 were retrospectively analyzed. Among them, 44 patients underwent abdominal operation (abdominal group), and 42 patients underwent thoracoabdominal radical gastrectomy (thoraco-abdominal group). The operation time, lymph node number, distance between the tumor and cutting edge, amount of intraoperational blood loss, postoperative pulmonary complications, and postoperative hospital stay in the two groups were compared.

RESULTS

Comparing the thoracoabdominal group with the abdominal group, the number of removed lymph nodes was 41.57±9.22 vs. 35.09±10.61 (P<0.01), the number of removed mediastinal lymph nodes was 6.38±1.50 vs. 3.52±1.42 (P<0.01), the distance between the tumor and cut edge was (5.62±0.73) cm vs. (3.30±0.85) cm (P<0.01), whereas the operation time, intraoperative blood loss, postoperative pulmonary complications, occurrence of anastomotic leakage and hospital stay were statistically not significantly different (P>0.05 for all).

CONCLUSIONS

For patients with advanced Siewert type Ⅱ adenocarcinoma of the esophagogastric junction, radical gastrectomy through thoracoabdominal approach can resect a longer segment of the esophagus, dissect more mediastinal lymph nodes, and does not increase post-operative complications and extend hospital stay, thus, exhibits obvious advantages in the surgical treatment of Siewert Ⅱ adenocarcinoma of the esophagogastric junction.

[Application of benchmark dose on renal injury in people chronically exposed to lead]

Objective: To screen sensitive indicators of renal injury in lead workers using benchmark dose method. Methods: Of the 486 subjects,116 did not occupationally contact to lead as a control. The blood lead was considered as exposure biomarker, while Uβ₂-MG and UNAG as effect biomarkers for renal injury. The BMD and BMDL of blood lead were estimated at the 10% benchmark response using BMDS Version 2.6. Results: There was statistical rise in blood lead between the lead group and control group (P<0.05) ; and the blood lead level was divided into four groups by quarterback spacing method, among which UNAG was statistically different (P<0.05) . There was an increased prevalence of abnormal rates of Uβ₂-MG and UNAG with increasing blood lead concentration (P<0.05) , after trend chi-square test. BMD and BMDL of UNAG and Uβ₂-MG were 602.784/431.838 μg/L and 130.398/100.981 μg/L caculated by Log-Probit model, respectively. Conclusions: Occupational lead exposure may cause kidney damage, and UNAG could be as a more sensitive marker for monitoring early renal injury than Uβ₂-MG.

Engineering Porous Poly(lactic acid) Scaffolds with High Mechanical Performance via a Solid State Extrusion/Porogen Leaching Approach

A knotty issue concerning the poor mechanical properties exists in the porogen leaching approach to porous scaffolds, despite its advantage in tuning pore structure. To address this hurdle, solid state extrusion (SSE) combined with porogen leaching was utilized to engineer porous scaffolds of poly(lactic acid) (PLA). Advances introduced by poly(ethylene glycol) (PEG) caused the PLA ductile to be processed and, on the other hand, enabled the formation of interconnected pores. Thus, a well-interconnected porous architecture with high connectivity exceeding 97% and elevated porosity over 60% was obtained in the as-prepared PLA scaffolds with the composition of NaCl higher than 75.00 wt % and PEG beyond 1.25 wt %. More strikingly, the pore walls of macropores encompassed countless micropores and rough surface topography, in favor of transporting nutrients and metabolites as well as cell attachment. The prominent compressive modulus of the PLA scaffolds was in the range of 85.7⁻207.4 MPa, matching the normal modulus of human trabecular bone (50⁻250 MPa). By means of alkaline modification to improve hydrophilicity, biocompatible porous PLA scaffolds exhibited good cell attachment. These results suggest that the SSE/porogen leaching approach provides an eligible clue for fabricating porous scaffolds with high mechanical performance for use as artificial extracellular matrices.

Super-Robust Polylactide Barrier Films by Building Densely Oriented Lamellae Incorporated with Ductile in Situ Nanofibrils of Poly(butylene adipate-co-terephthalate)

Remarkable combination of excellent gas barrier performance, high strength, and toughness was realized in polylactide (PLA) composite films by constructing the supernetworks of oriented and pyknotic crystals with the assistance of ductile in situ nanofibrils of poly(butylene adipate-co-terephthalate) (PBAT). On the basis that the permeation of gas molecules through polymer materials with anisotropic structure would be more frustrated, we believe that oriented crystalline textures cooperating with inerratic amorphism can be favorable for the enhancement of gas barrier property. By taking full advantage of intensively elongational flow field, the dispersed phase of PBAT in situ forms into nanofibrils, and simultaneously sufficient row-nuclei for PLA are induced. After appropriate thermal treatment with the acceleration effect of PBAT on PLA crystallization, oriented lamellae of PLA tend to be more perfect in a preferential direction and constitute into a kind of network interconnecting with each other. At the same time, the molecular chains between lamellae tend to be more extended. This unique structure manifests superior ability in ameliorating the performance of PLA film. The oxygen permeability coefficient can be achieved as low as 2 × 10(-15) cm(3) cm cm(-2) s(-1) Pa(-1), combining with the high strength, modulus, and ductility (104.5 MPa, 3484 MPa, and 110.6%, respectively). The methodology proposed in this work presents an industrially scalable processing method to fabricate super-robust PLA barrier films. It would indeed push the usability of biopolymers forward, and certainly prompt wider application of biodegradable polymers in the fields of environmental protection such as food packaging, medical packaging, and biodegradable mulch.

Colon cancer with unresectable synchronous metastases: the AAAP scoring system for predicting the outcome after primary tumour resection

AIM

The aim of this study was to develop a prognostic scoring system to predict the outcome of patients with unresectable metastatic colon cancer who received primary colon tumour resection.

METHOD

Patients with confirmed metastatic colon cancer treated at the Peking University Cancer Hospital between 2003 and 2012 were reviewed retrospectively. The correlation of clinicopathological factors with overall survival was analysed using the Kaplan-Meier method and the log-rank test. Independent prognostic factors were identified using a Cox proportional hazards regression model and were then combined to form a prognostic scoring system.

RESULTS

A total of 110 eligible patients were included in the study. The median survival time was 10.4 months and the 2-year overall survival (OS) rate was 21.8%. Age over 70 years, an alkaline phosphatase (ALP) level over 160 IU/l, ascites, a platelet/lymphocyte ratio (PLR) above 162 and no postoperative therapy were independently associated with a shorter OS in multivariate analysis. Age, ALP, ascites and PLR were subsequently combined to form the so-called AAAP scoring system. Patients were classified into high, medium and low risk groups according to the score obtained. There were significant differences in OS between each group (P < 0.001).

CONCLUSION

Age, ALP, ascites, PLR and postoperative therapy were independent prognostic factors for survival of patients with metastatic colonic cancer who underwent primary tumour resection. The AAAP scoring system may be a useful tool for surgical decision making.

Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au+Au Collisions at √[sNN]=200 GeV

We present high precision measurements of elliptic flow near midrapidity (|y|<1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy √[sNN]=200  GeV. We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2.

JAK-STAT and G-protein-coupled receptor signaling pathways are frequently altered in epitheliotropic intestinal T-cell lymphoma

Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.

Understanding Nonlinear Dielectric Properties in a Biaxially Oriented Poly(vinylidene fluoride) Film at Both Low and High Electric Fields

Understanding nonlinear dielectric behavior in polar polymers is crucial to their potential application as next generation high energy density and low loss dielectrics. In this work, we studied nonlinear dielectric properties of a biaxially oriented poly(vinylidene fluoride) (BOPVDF) film under both low and high electric fields. For fundamental nonlinear dielectric constants at low fields (<30 MV/m), Novocontrol high-voltage broadband dielectric spectroscopy (HVBDS) was accurate enough to measure up to the third harmonics. It was observed that the low-field dielectric nonlinearity for the BOPVDF disappeared above 10 Hz at room temperature, suggesting that the low-field dielectric nonlinearity originated from ionic migration of impurity ions rather than dipolar relaxation of the amorphous segments. Above the coercive field (EC ≈ 70 MV/m), bipolar electric displacement-electric field (D-E) loop tests were used to extract the nonlinear behavior for pure PVDF crystals, which had a clear origin of ferroelectric switching of polar crystalline dipoles and domains and nonpolar-to-polar (α → δ → β) phase transformations. By using HVBDS, it was observed that the ferroelectric switching of polar crystalline dipoles and domains in BOPVDF above the EC always took place between 20 and 500 Hz regardless of a broad range of temperature from -30 to 100 °C. This behavior was drastically different from that of the amorphous PVDF dipoles, which had a strong dependence on frequency over orders of magnitude.