In-situ synthesis of Pt nanoparticles/reduced graphene oxide/cellulose nanohybrid for nonenzymatic glucose sensing.

In recent years, nanocellulose-based bioinorganic nanohybrids have been exploited in numerous applications due to their unique nanostructure, excellent catalytic properties, and good biocompatibility. To the best of our knowledge, this is the first report on the simple and effective synthesis of graphene/cellulose (RGO/CNC) matrix-supported platinum nanoparticles (Pt NPs) for nonenzymatic electrochemical glucose sensing. The Pt/RGO/CNC nanohybrid presented a porous network structure, in which Pt NPs, RGO, and CNCs were integrated well. Here, cellulose nanocrystals act as a biocompatible framework for wrapped RGO and monodispersed Pt nanoparticles, effectively preventing the restacking of graphene during reduction. The superior glucose sensing performance of Pt/RGO/CNC modified glass carbon electrode (GCE) was achieved with a linear concentration range from 0.005 to 8.5 mM and a low detection limit of 2.1 µM. Moreover, the Pt/RGO/CNC/GCE showed remarkable sensitivity, selectivity, durability, and reproducibility. The obtained results indicate that the CNCs-based bioinorganic nanohybrids could be a promising electrode material in electrochemical biosensors.

Protein from Hylocereus polyrhizus protects MRC-5 cells against hydrogen peroxide (H2O2)-induced damage.

The cytoprotective and potential molecular mechanisms of Hylocereus polyrhizus protein (RFPP) were investigated on the hydrogen peroxide (H2O2)-triggered damage in normal human embryonic lung (MRC-5) cells. An MTT assay was conducted to assess the MRC-5 cell viability after exposure to H2O2 or RFPP. Cell cycle distribution and apoptosis were explored via flow cytometry. The contents of related proteins were assessed via western blot. MRC-5 cells exhibited markedly decreased cellular viability after treatment with H2O2; however, treatment with RFPP suppressed this decrease. Additionally, RFPP interference dampened H2O2-triggered intracellular apoptosis levels and increased H2O2-triggered intracellular S phase. In these processes, the contents of phosphorylated (p)-AKT along with p-mTOR proteins were downregulated in 120 µM H2O2-treated cells compared with vehicle-treated cells. Nevertheless, in MRC-5 cells inoculated with RFPP, the levels expression of these proteins were reversed. To conclude, RFPP protected MRC-5 cells from H2O2-triggered damage via activation of the PI3K/AKT/mTOR cascade.

Application of Fullerenes as Photosensitizers for Antimicrobial Photodynamic Inactivation: A Review.

Antimicrobial photodynamic inactivation (aPDI) is a newly emerged treatment approach that can effectively address the issue of multidrug resistance resulting from the overuse of antibiotics. Fullerenes can be used as promising photosensitizers (PSs) for aPDI due to the advantages of high triplet state yields, good photostability, wide antibacterial spectrum, and permissibility of versatile functionalization. This review introduces the photodynamic activities of fullerenes and the up-to-date understanding of the antibacterial mechanisms of fullerene-based aPDI. The most recent works on the functionalization of fullerenes and the application of fullerene derivatives as PSs for aPDI are also summarized. Finally, certain remaining challenges are emphasized to provide guidance on future research directions for achieving clinical application of fullerene-based aPDI.

A randomized study on the effect of sequential acupoint stimulation on pulmonary function of patients with spontaneous pneumothorax during VATS perioperative period.

This study aims to explore the effect of sequential acupoint stimulation on the postoperative pulmonary function of patients with spontaneous pneumothorax who underwent video-assisted thoracoscopic surgery (VATS).Using a random number table, the patients were randomly divided into 2 groups: routine nursing group and sequential acupoint stimulation group. Patients in the routine nursing group received standard nursing care of thoracic surgery, while patients in the acupoint group received sequential acupoint stimulation on Shenshu (BL23), Gaohuang (BL43), Feishu (BL13), and Tiantu (CV22). Then, the maximal ventilatory volume (MVV), oxygen saturation (SpO2), postoperative drainage volume, postoperative drainage time, postoperative hospitalization days, and procalcitonin (PCT) were observed on the first, third, fifth and 30th day after VATS operation.On the fifth day after spontaneous pneumothorax was treated with VATS, MVV, and SpO2 of the sequential acupoint stimulation group were significantly higher than those of the routine nursing group (P < .05). On both the third day and fifth day after VATS, PCT of the sequential acupoint stimulation group was significantly lower than that of the routine nursing group (P < .01). Furthermore, the difference in postoperative drainage volume between the 2 groups was not statistically significant (P > .05), while chest tube drainage time (P < .01) and postoperative hospitalization days (P < .05) of the sequential acupoint stimulation group were significantly lower than those of the routine nursing group.In spontaneous pneumothorax patients who underwent VATS, sequential acupoint stimulation nursing was significantly more effective than routine postoperative nursing in promoting postoperative recovery of lung function, alleviating inflammatory response and shortening hospitalization days.

Cellulose nanocrystal driven microphase separated nanocomposites: Enhanced mechanical performance and nanostructured morphology.

The interest in the modification of cellulose nanocrystals (CNCs) lies in the potential to homogenously disperse CNCs in hydrophobic polymer matrices and to promote interfacial adhesion. In this work, poly(methyl methacrylate) (PMMA) and poly(butyl acrylate) (PBA) were grafted onto CNCs, thereby imparting their hydrophobic traits. The successful grafting modification led to the increased thermal stability of modified CNCs (MCNCs), and the hydrophobic surface modification was integrated with crystalline structure and morphology of CNCs. The nanocomposites with 7 wt% MCNCs/PBA-co-PMMA had an increase in Young's modulus of >25-fold and in tensile strength at about 3 times compared to these of neat PBA-co-PMMA copolymer. In addition, a micro-phase separated morphology (PBA soft domains, and PMMA and CNC hard domains) of MCNCs/PBA-co-PMMA nanocomposites was observed. The large increase in the storage moduli (glass transition temperatures) and organized morphology of MCNCs/PBA-co-PMMA nanocomposites also elucidated the relationship between mechanical properties and micro-phase separated morphology. Therefore, the MCNCs are effective reinforcing agents for the PBA-co-PMMA thermoplastic elastomers, opening up opportunities for their wide-spread applications in polymer composites.

Influence of Cellulose Nanoparticles on Rheological Behavior of Oil Well Cement-Water Slurries.

Performance of hardened oil well cement (OWC) is largely determined by the rheological properties of the cement slurries. This work was carried out to investigate the effect of water- to-cement ratio (WCR) and cellulose nanoparticles (CNPs), including cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), on rheology performance of OWC-based slurries using a Couette rotational viscometer coupled with rheological models. The yield stress and viscosity of neat OWC slurries had a decreasing trend with the increase of WCRs. The suspension became increased unstable with the increase of WCRs. The properties of CNPs, including rheological behaviors, surface properties and morphology, determine the rheological performance of CNP-OWC slurries. In comparison with CNC-OWC slurries, the gel strength, yield stress and viscosity of CNF-OWC slurries were higher as CNFs were more likely to form an entangled network. The gel strength, yield stress and viscosity of CNP-OWC slurries increased with reduced CNF size through regrinding and the proportion of CNFs in the mixture of CNFs and CNCs, respectively.

MiR-770 inhibits tumorigenesis and EMT by targeting JMJD6 and regulating WNT/ß-catenin pathway in non-small cell lung cancer.

AIMS: MicroRNAs (miRNAs) plays important role in development and disease, especially in cancer including non-small cell lung cancer (NSCLC). However, the role of miR-770 in NSCLC remains unclear. In this study, we aimed to study the function and mechanism of miR-770 in tumorigenesis of NSCLC. MAIN METHODS: RT-qPCR was used to measure the expression levels of miR-770 in NSCLC tissues and cells. MTT assay, colony formation assay, flow cytometric analysis and transwell migration and invasion assays were performed to investigate the role of miR-770 in NSCLC cells. Bioinformatics and luciferase reporter analyses were used to demonstrate that whether the Jumonji domain-containing 6 (JMJD6) as a direct target of miR-770. The function of JMJD6 in NSCLC was also investigated. Finally, in vivo animal experiment was used to study whether miR-770 was capable of inhibiting tumor growth by inhibiting JMJD6. KEY FINDINGS: We first showed that miR-770 was downregulated in NSCLC tissues and cell lines, and the low expression of miR-770 was correlated with poor patient survival in NSCLC patients. miR-770 acted on a tumor suppressor by binding to the 3'UTR of JMJD6 and downregulated its expression in NSCLC cells. This study also demonstrated that JMJD6 played as an oncogene in NSCLC cells. miR-770 overexpression was capable of inhibiting NSCLC tumor growth by inhibiting JMJD6 and its downstream WNT/ß-catenin pathway both in vitro and in vivo. SIGNIFICANCE: The present study indicated that miR-770 functioned as a tumor suppressor and it might be a potential biomarker and therapeutic target in NSCLC.

Electrospun Nanofibers Made of Silver Nanoparticles, Cellulose Nanocrystals, and Polyacrylonitrile as Substrates for Surface-Enhanced Raman Scattering.

Nanofibers with excellent activities in surface-enhanced Raman scattering (SERS) were developed through electrospinning precursor suspensions consisting of polyacrylonitrile (PAN), silver nanoparticles (AgNPs), silicon nanoparticles (SiNPs), and cellulose nanocrystals (CNCs). Rheology of the precursor suspensions, and morphology, thermal properties, chemical structures, and SERS sensitivity of the nanofibers were investigated. The electrospun nanofibers showed uniform diameters with a smooth surface. Hydrofluoric (HF) acid treatment of the PAN/CNC/Ag composite nanofibers (defined as p-PAN/CNC/Ag) led to rougher fiber surfaces with certain pores and increased mean fiber diameters. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results confirmed the existence of AgNPs that were formed during heat and HF acid treatment processes. In addition, thermal stability of the electrospun nanofibers increased due to the incorporation of CNCs and AgNPs. The p-PAN/CNC/Ag nanofibers were used as a SERS substrate to detect p-aminothiophenol (p-ATP) probe molecule. The results show that this substrate exhibited high sensitivity for the p-ATP probe detection.

Thermoresponsive dendronized polyprolines via the "grafting to" route.

The first and second generations of dendronized polyprolines P3G1, P3G2, and P4G1 are prepared via the "grafting to" route, and their thermoresponsive properties and helical conformations investigated. High molar masses of polyproline main chains carrying azido groups are achieved first by polycondensation of peptide precursors through activated ester strategy. Oligoethylene glycol dendrons cored with alkyne are then attached onto the main chains through click reaction. These polymers are found to be thermoresponsive. Circular dichroism spectroscopy investigation indicates, in contrast to P3G2 and P4G1 which adopt the expected PPII conformation in aqueous conditions, P3G1 prefers to adopt PPI helical conformation, and this conformation is stable within the measured time period and temperature range.

Remarkable structure effects on chiroptical properties of polyisocyanides carrying proline pendants.

Chiral polymers with simple chemical structures and high helical conformation stabilities are important for their applications as chiral supports and asymmetrical catalysts. We report herein the synthesis of a series of aliphatic polyisocyanides carrying proline pendants of different chiralities, and an investigation of the effects of the chemical structures of these pendants on the chiroptical properties of the polymers. The configuration of the chiral center at the 4-position of the proline pendants was changed from S to R to check its effect on the handedness of the helical conformation. To examine the effects of steric hindrance on the stabilities of the helical conformation for these aliphatic representatives, proline pendants with various substituents at both the carboxyl and amine terminals were designed. To further examine the steric effects of the proline pendants, aromatic counterparts were also prepared. In the latter case, the effects of hydrogen bonds between pendant units on the enhancement and stabilities of the helical conformation were investigated by switching from the ester to an amide linkage. The Cotton effects and signal intensities of both aliphatic and aromatic polyisocyanides from circular dichroism spectroscopy were compared based on the bulkiness of the pendant groups, solvent polarities, and solution temperatures. It was found that highly stable helical conformations of polyisocyanides could be imposed by small bulky monoproline pendants.

Load-collapse-release cascades of amphiphilic guest molecules in charged dendronized polymers through spatial separation of noncovalent forces.

The ability to pack guest molecules into charged dendronized polymers (denpols) and the possibility to release these guest molecules from subsequently densely aggregated denpols in a load-collapse-release cascade is described. Charged denpols, which constitute molecular objects with a persistent, well-defined envelope and interior, are capable of incorporating large amounts of amphiphilic guest molecules. Simultaneously, multivalent ions can coordinate to the surfaces of charged denpols, leading to counterion-induced aggregation of the already guest-loaded host structures. Thus, although the local guest concentration in denpol-based molecular transport might already be initially high due to the dense guest packing inside the dendritic denpol scaffolding, the "local" guest concentration can nonetheless be further increased by packing (through aggregation) of the host-guest complexes themselves. Subsequent release of guest compounds from densely aggregated dendronized polymers is then possible (e.g., through increasing the solution concentration of imidazolium-based ions). Augmented with this release possibility, the concept of twofold packing of guests, firstly through hosting itself and secondly through aggregation of the hosts, gives rise to a load-collapse-release cascade that strikingly displays the high potential of dendronized macromolecules for future molecular transport applications.

Liquid crystalline period variations in self-assembled block copolypeptides-surfactant ionic complexes.

We investigate the complexation of ampholytic poly(N-isopropylacylamide)-block-poly- (L-glutamic acid)-block-poly(L-lysine) (PNiPAM-b-PLG-b-PLLys) triblock copolymers and PNiPAM-block-(PLG-co-PLLys) diblock copolymers with counter charged anionic and cationic surfactants. Both triblock and diblock copolymers are able to selectively form complexes through either L-glutamic acid-cationic surfactant or L-lysine-anionic surfactant ionic pairs, depending on the protonated or deprotonated states of the ampholytic peptide units. The complexes show ordering at multiple length scales: i) the block copolymer length scale (10(1) nm), ii) the liquid crystalline length scale (10(0) nm), and, iii) the peptidic secondary structures length scale (10(0) nm). We show that the liquid crystalline period can be tuned by varying the random/block copolypeptide architectures and the composition of the ampholytic amino acid species.

Stimuli-responsive zwitterionic block copolypeptides: poly(N-isopropylacrylamide)-block-poly(lysine-co-glutamic acid).

Synthesis of novel zwitterionic block copolypeptides, poly(N-isopropylacrylamide)-block-poly(L-glutamic acid-co-L-lysine) [PNiPAM(n)(PLG(x)-co-PLLys(y))m , where n is the number-average degree of polymerization (DP(n)) of PNiPAM block, x and y are the mole fraction of glutamic acid and lysine residues, respectively, and m is the total DP(n) of the peptide block], and their stimuli-responsiveness to temperature and pH variation in aqueous solutions are described. Initiated with the amino-terminated poly(N-isopropylacrylamide) (PNiPAM(n)-NH2), ring-opening polymerization (ROP) of a mixture of gamma-benzyl-L-glutamate N-carboxyanhydride (BLG-NCA), and Boc-L-lysine N-carboxyanhydride (BLLys-NCA) afforded the block copolypeptides PNiPAM(n)(PBLG(x)-co-PBLLys(y))m, with a poly(N-isopropylacrylamide) block together with a random copolypeptide block, which was then deprotected with HBr/trifluoroacetic acid into the double hydrophilic block copolypeptides, PNiPAM(n)(PLG(x)-co-PLLys(y))m. Their block ratios and lengths, as well as the amino acid residue ratios in the random copolypeptide block are varied (n = 360, x = 0.4-0.5, y = 0.4-0.6, and m = 220-252). The secondary structures of the copolypeptides in aqueous solution at different pH conditions were examined. Phase transitions in aqueous solutions induced by both pH and temperature variation were investigated by (1)H NMR spectroscopy. The transitions induced by temperature were also explored by turbidity measurements using UV/vis spectroscopy for their lower critical aggregation temperature (LCAT) determination. Furthermore, these aggregation processes were followed by dynamic light scattering measurements.

Synthesis and characterization of thermo- and pH-responsive double-hydrophilic diblock copolypeptides.

Synthesis of novel double-hydrophilic diblock copolypeptides (BCPs), poly(l-glutamic acid)-block-poly(N-isopropylacrylamide) (PLGnPNm), and their thermoresponsive properties in aqueous solutions at different pH values are described. The diblock copolypeptides were synthesized by a combination of ring-opening polymerization (ROP) of gamma-benzyl-l-glutamate N-carboxyanhydrides (BLG-NCA) and reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NiPAM). A new class of RAFT agents (CTA-2 and CTA-3) with amino-functional groups was designed for this purpose. Two different strategies, i.e., macrochain transfer agent (CTA) and macroinitiator routes, were utilized and compared on the control of the chemical structures of the resulting BCPs. Their block ratios and lengths are broadly varied (n = 21-600 and m =180-442). Their thermally switchable aggregation behaviors in aqueous solutions were investigated at the microscopic level by 1H NMR spectroscopy and at the macroscopic level by turbidity measurements using UV/vis spectroscopy. The latter was also utilized for their lower critical aggregation temperature (LCAT) determination. The effects of block lengths and ratios as well as solution pH values on the collapse of NiPAM chain and aggregation process of BCPs were examined. This aggregation process was also followed by dynamic light scattering (DLS) measurements, and the thermally induced aggregate structures were investigated by transmission electron microscopy (TEM).

[Application of SELDI-TOF MS technology analyzing serum protein profiling for distinguishing laryngeal carcinoma from ordinary people].

OBJECTIVE: To analyze the spectrometric serum protein profiling of laryngeal carcinoma and healthy controls by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS), to establish serum marker pattern for the diagnosis of laryngeal carcinoma. METHOD: The serum samples of 46 cases of laryngeal carcinoma, 51 cases of healthy controls on WCX2 proteinchip, were collected. the spectrometric protein profiling was defected by SELDI-TOF-MS, the data were analyzed by Biomarker Patterns Software provided by Ciphergen Corp. A primary diagnosis model of laryngeal carcinoma was set up. This model was further evaluated by blind test with other l2 cases patients and 13 cases healthy controls. RESULT: Seventy-six protein peaks were detected at the molecular range of 2000-20000 Da., among which 27 ones were significantly different between laryngeal carcinoma and controls( P < 0.05). A diagnostic pattern consisting of 3 protein peaks was established with of accuracy 88.7% (86/97), sensitivity 87% (40/46), specificity 90.2% (46/51), Blind test generated a sensitivity of 83.3% (10/12)and specificity of 84.6% (11/13) respectively. CONCLUSION: It is successful to develop and evaluate the different spectrometric protein profiling patterns of laryngeal carcinoma and healthy control by SELDI-TOF-MS. This affords possibly a new method to early diagnosis of laryngeal carcinoma.

[The application of multi-slice computed tomograph in diagnosis and operation of hypopharyngeal carcinoma].

OBJECTIVE: To evaluate the clinical application of multi slice CT(MSCT) in hypopharyngeal carcinoma and serve otolaryngologist to institute proper operation. METHOD: Forty-five patients with hypopharyngeal carcinoma scanned by MSCT were studied and confirmed by operation and pathologic examination. The operation material were retrospectively analyzed. All the cases were used for the enhancement scanning, whose scope was from hard palate to cervical segments of esophagus. RESULT: Of 45 cases, 34 cases derived from piriform fossa, 7 cases were from the postcricoid region and 4 cases were in the posterior wall of hypopharynx. The tumor showed isodense or mixed density and slightly enhancement, piriform fossa became narrow or disappeared, retropharyngeal soft tissue thickened, laryngeal cartilage and esophageal ostium were invaded and lymph nodes of neck became metastasis. The tumor pushed the annular and arytenoids cartilage displacement anteriorly; the thyroid arytenoidal gap and cricothyroid joint were widened. The operation plan that was made according as MSCT was almost agreed with actual operation. The consistent rate is 91.1% (41/45). CONCLUSION: MSCT examination can accurately diagnose and exhibit the extension of the tumors and detect metastasis to lymph nodes, and provide reliable basis for surgery therapy.

[Long-term results analysis of mastoidectomy for chronic otitis media].

OBJECTIVE: To study the operative indications of chronic otitis media and their long-term results. METHOD: One hundred and forty-five cases of mastoidectomy were followed for 5 years between 1995-1998. We discussed the results of recurrence and hearing level of radical mastoidectomy, canal wall up mastoidectomy (CWUM) and canal wall down mastoidectomy with mastoid obliteration (CWDM). Advantages and disadvantages were analyzed by the rate of visiting. RESULT: RM is almost invariable in hearing. There is no significant difference between CWDM [improved (10.84+/-4.63) dB HL] and CWUM [improved (10.39+/-3.93) dB HL]. The recurrence rate of RM was 11.63%, CWDM was 12.68%, but the CWUM was 22.58%. Rate of re-visiting of RM is obviously higher that of CWUM and CWDM. CONCLUSION: RM, CWUM and CWDM have all advantages, but the indication must be selected carefully. The effect of CWDM is better than that of RM and CWUM for the long-term results in these cases.

[The role of high-resolution CT in the preoperative assessment of chronic otitis media].

OBJECTIVE: To assess the high-resolution CT scan in depicting the middle ear structures. METHOD: The surgical findings of 51 ears operated on were retrospectively compared with the CT findings. The followings were analysed: diagnostic features of chronic otitis media (COM) on CT status of the middle ear structures (ossicles, facial nerve canal, semicircular canals and tegmen tympani), and anatomical variations. RESULT: The radio-surgical agreement was excellent for the malleus (kappa statistics, k = 0.840) and tegmen (0.788), good for the incus (0.700) and semicircular canals (0.56), but poor for the stapes (0.366) and facial nerve dehiscence (0.310). Potential surgical hazards detected by the scans included: Low lying dura, high jugular bulb, anterior lying sigmoid sinus, facial nerve dehiscence and other situations brought about by the destructive nature of the lesion. CONCLUSION: There is a good radio-surgical correlation in COM for most middle ear structures except for the integrity of the facial canal and stapes. The scan alerts the surgeon the potential surgical dangers and complications of disease. High-resolution CT scan should be a routine examination prior to middle ear and mastoid surgery.