Mechanically robust bamboo node and its hierarchically fibrous structural design.

Although short bamboo nodes function in mechanical support and fluid exchange for bamboo survival, their structures are not fully understood compared to unidirectional fibrous internodes. Here, we identify the spatial heterostructure of the bamboo node via multiscale imaging strategies and investigate its mechanical properties by multimodal mechanical tests. We find three kinds of hierarchical fiber reinforcement schemes that originate from the bamboo node, including spatially tightened interlocking, triaxial interconnected scaffolding and isotropic intertwining. These reinforcement schemes, built on porous vascular bundles, microfibers and more-refined twist-aligned nanofibers, govern the structural stability of the bamboo via hierarchical toughening. In addition, the spatial liquid transport associated with these multiscale fibers within the bamboo node is experimentally verified, which gives perceptible evidence for life-indispensable multidirectional fluid exchange. The functional integration of mechanical reinforcement and liquid transport reflects the fact that the bamboo node has opted for elaborate structural optimization rather than ingredient richness. This study will advance our understanding of biological materials and provide insight into the design of fiber-reinforced structures and biomass utilization.

Bioinspired Impact-Resistant and Self-Monitoring Nanofibrous Composites.

Lightweight and impact-resistant materials with self-monitoring capability are highly desired for protective applications, but are challenging to be artificially fabricated. Herein, a scalable-manufactured aramid nanofiber (ANF)-based composite combining these key properties is presented. Inspired by the strengthening and toughening mechanisms relying on recoverable interfaces commonly existing in biological composites, mechanically weak but dense hydrogen bonds are introduced into the ANF interfaces to achieve simultaneously enhanced tensile strength (300 MPa), toughness (55 MJ m-3 ), and impact resistance of the nanofibrous composite. The achieved mechanical property combination displays attractive advantages compared with that of most of previously reported nanocomposites. Additionally, the nanofibrous composite is designed with a capability for real-time self-monitoring of its structural safety during both quasi-static tensile and dynamic impact processes, based on the strain/damage-induced resistance variations of a conductive nanowire network inside it. These comprehensive properties enable the present nanofibrous composite with promising potential for protective applications.

Large-Scale Production of Rectorite Nanosheets and Their Co-Assembly with Aramid Nanofibers for High-Performance Electrical Insulating Nanopapers.

Compared with raw rectorite microplatelets (RMs), rectorite nanosheets (RNs) have considerably greater application prospects in the preparation of advanced composite materials because of their larger aspect ratio, higher surface reactivity, and intrinsically superior mechanical and physical properties. However, the difficulty in the efficient preparation of RNs significantly limits their large-scale applications. Here, a scalable poly(vinylpyrrolidone)-assisted stirring approach is developed to prepare ultrathin RNs from the abundant natural RMs. A higher production rate (≈0.675 g h-1 ) is achieved compared with that of most other nanosheets. Additionally, instead of using conventional time- and energy-consuming high-speed centrifugation, an efficient poly(dienedimethylammonium chloride)-assisted sedimentation strategy is proposed here to rapidly separate the exfoliated RNs from the RN dispersion. Then, the RNs are co-assembled with aramid nanofibers (ANFs) into large-scale nacre-mimetic ANF-RN nanopapers with considerably enhanced mechanical, electrical insulating, and high-temperature-resistant properties compared with pure ANF nanopapers and ANF-RM micropapers. Moreover, these properties are superior to those of previously reported ANF-based nanopapers and commercial insulating micropapers.

Double-Layer Nacre-Inspired Polyimide-Mica Nanocomposite Films with Excellent Mechanical Stability for LEO Environmental Conditions.

Owing to their outstanding comprehensive performance, polyimide (PI) composite films are widely used on the external surfaces of spacecraft to protect them from the adverse conditions of low Earth orbit (LEO). However, current PI composite films have inadequate mechanical properties and atomic oxygen (AO) resistance. Herein, this work fabricates a new PI-based nanocomposite film with greatly enhanced mechanical properties and AO resistance by integrating mica nanosheets with PI into a unique double-layer nacre-inspired structure with a much higher density of mica nanosheets in the top layer. In addition, the unique microstructure and the intrinsic properties of mica also impart the nanocomposite film with favorable ultraviolet and high-temperature resistance. The comprehensive performance of this material is superior to those of pure PI, single-layer PI-mica, and previously reported PI-based composite films. Thus, the double-layer nanocomposite film displays great potential as an aerospace material for use in LEO.

Nacreous aramid-mica bulk materials with excellent mechanical properties and environmental stability.

Low density, high strength and toughness, together with good environmental stability are always desirable but hardly to achieve simultaneously for man-made structural materials. Replicating the design motifs of natural nacre clearly provides one promising route to obtain such kind of materials, but fundamental challenges remain. Herein, by choosing aramid nanofibers and mica microplatelets as building blocks, we produce a nacreous aramid-mica bulk material with a favorable combination of low density (∼1.7 g cm-3), high strength (∼387 MPa) and toughness (∼14.3 MPa m1/2), and impressive mechanical stability in some harsh environments, including acid/alkali solutions, strong ultraviolet radiation, boiling water, and liquid nitrogen, standing out from previously reported biomimetic bulk composites. Moreover, the obtained material outperforms other bulk nacre-mimetics and most engineering structural materials in terms of its specific strength (227 MPa/[Mg m-3]) and specific toughness (8.4 MPa m1/2/[Mg m-3]), making it a new promising engineering structural material for different technical fields.

Luteolin Protects Pheochromocytoma (PC-12) Cells against Aß 25-35-Induced Cell Apoptosis through the ER/ERK/MAPK Signalling Pathway.

The regulatory effect of luteolin on the progression of Alzheimer's disease (AD) remains unclear from the perspective of apoptosis. The present study aimed to investigate the protective effects of luteolin against Aß 25-35-induced cell apoptosis in pheochromocytoma (PC-12) cells. Aß 25-35 was used to induce an in vitro model of AD. Estradiol was used as a positive control. The PC-12 cells were incubated with luteolin alone or in combination with fulvestrant or U0126. The results showed that luteolin treatment significantly prevents Aß 25-35-induced decrease in cell viability and inhibits Aß 25-35-induced cell apoptosis. After the addition of fulvestrant and U0126, the apoptosis rate of PC-12 cells increased significantly. In addition, luteolin treatment significantly upregulated the expression of Bcl-2 and downregulated the expression of Bax and caspase-3, whereas fulvestrant and U0126 partially reversed the effects of luteolin. Moreover, luteolin treatment upregulated the expression of ERß and p-ERK1/2, whereas fulvestrant blocked the expression of p-ERK1/2. The study showed that luteolin could activate the ER/ERK/MAPK signalling pathway to protect PC-12 cells against Aß 25-35-induced cell apoptosis via selectively acting on ERß. Thus, luteolin may be considered as a potential novel therapeutic strategy for AD.

Transforming ground mica into high-performance biomimetic polymeric mica film.

Biomimetic assembly of high-quality nanosheets into nacre-like structures can produce macroscopic films with favorable mechanical and optical performances due to the intrinsic properties and high level of ordering of the nanoscale building blocks. Natural ground mica is abundant and exhibits great application potential. However, large size and low aspect ratio greatly limit its biomimetic assembly. Moreover, exfoliation of ground mica into high-quality nanosheets remains a significant challenge. Here, we report that large-scale exfoliation of ground mica into mono- or few-layered mica nanosheets with a production rate of ~1.0 g h-1 can be successfully achieved. The mica nanosheets are then assembled into strong biomimetic polymeric mica film that inherits the high electric insulation, excellent visible transmittance, and unique ultraviolet-shielding properties of natural mica. Its overall performance is superior to that of natural sheet mica and other biomimetic films, making the polymeric mica film a suitable substrate for flexible and transparent devices.

Nacre-mimic Reinforced Ag@reduced Graphene Oxide-Sodium Alginate Composite Film for Wound Healing.

With the emerging of drug-resistant bacterial and fungal pathogens, there raise the interest of utilizing versatile antimicrobial biomaterials to treat the acute wound. Herein, we report the spraying mediated assembly of a bio-inspired Ag@reduced graphene-sodium alginate (AGSA) composite film for effective wound healing. The obtained film displayed lamellar microstructures similar to the typical "brick-and-mortar" structure in nacre. In this nacre-mimic structure, there are abundant interfacial interactions between nanosheets and polymeric matrix, leading to remarkable reinforcement. As a result, the tensile strength, toughness and Young's modulus have been improved 2.8, 2.3 and 2.7 times compared with pure sodium alginate film, respectively. In the wound healing study, the AGSA film showed effective antimicrobial activities towards Pseudomonas aeruginosa, Escherichia coli and Candida albicans, demonstrating the ability of protecting wound from pathogenic microbial infections. Furthermore, in vivo experiments on rats suggested the effect of AGSA film in promoting the recovery of wound sites. According to MTT assays, heamolysis evaluation and in vivo toxicity assessment, the composite film could be applied as a bio-compatible material in vitro and in vivo. Results from this work indicated such AGSA film has promising performance for wound healing and suggested great potential for nacre-mimic biomaterials in tissue engineering applications.

Lanthanide co-doped paramagnetic spindle-like mesocrystals for imaging and autophagy induction.

We synthesized two novel lanthanide doped spindle-like mesocrystals, YF3:Ce,Eu,Gd and YF3:Ce,Tb,Gd (abbreviated as YEG and YTG mesospindles, respectively). Both of them possess paramagnetic and fluorescent properties, and their excellent cyto-compatibility and low haemolysis are further confirmed. Therefore, they could act as dual mode contrast agents for magnetic resonance imaging (MRI) and fluorescence imaging. Furthermore, YEG and YTG mesospindles induce dose and time dependent autophagy by activating the PI3K signaling pathway. The autophagy induced by YEG and YTG mesocrystals is confirmed by enhanced autophagosome formation, normal cargo degradation, and no disruption of lysosomal function. This work is important to illustrate how rare-earth mesocrystals affect the autophagic pathway, indicating the potential of the YEG and YTG mesospindles in diagnosis and therapy.

[Effects of Acupuncture on Neurofunction and Neuropsychological Factors of Chronic Alcoholic Peripheral Neuropathy Patients].

OBJECTIVE: To observe the effects of acupuncture on neurofunction and neuropsychological factors of chronic alcoholic peripheral neuropathy (CAPN) patients. METHODS: Totally 120 CAPN patients were assigned to the common treatment group, acupuncture group A, and acupuncture group B according to random digit table, 40 in each group. All patients recieved conventional drug therapy. Besides, patients in the acupuncture group A were additionally needled at Pishu (BL20), Weishu (BL21), Xuehai (SP10), Yinlingquan (SP9), Zusanli (ST36), Yanglingquan (GB34), Jiexi (ST41), Xuanzhong (GB39), Xiangu (ST43),Taixi (KI3), Quchi (LI11), Waiguan (SJ5), Hegu (LI4), and so on. On these bases patients in the acupuncture group B were needled at Sishencong (EX-HN1), Yintang (EX-HN3), Neiguan (PC6), Taichong (LR3), Sanyinjiao (SP6), and Taiyang (EX-HN5). Acupuncture was performed once a day, 14 times as a course; and then once on every other day, 14 times in total for 4 weeks. All treatment lasted for 8 successive weeks. Neuropathy Impairment Score in the Lower Limbs (NIS-LL), Neurological Severity Score (NSS), Hamilton Depression Scale (HAMD), and Hamilton Anxiety Scale (HAMA) were assessed, motor nerve conduction velocity (MCV) and sensory nerve conduction velocity (SCV) were detected before and after treatment. RESULTS: After 8 weeks of treatment the scores of NIS-LL and NSS significantly decreased in the 3 groups, with statistical difference as compared with before treatment (P < 0.05). Scores of NIS-LL and NSS decreased more in acupuncture groups A and B than in the common treatment group (P < 0.05), and more obvious in acupuncture group B (P < 0.05). Compared with the same group before treatment, MCV and SCV of median nerve, ulnar nerve, common peroneal nerve and tibial nerve increased in acupuncture treatment group A and B after 8-week treatment (P < 0.05). MCV of median nerve, MCV and SCV of common peroneal nerve and tibial nerve significantly increased in the common treatment group (P < 0.05). Compared with the common treatment group, SCV of median nerve, MCV and SCV of ulnar nerve, common peroneal nerve and tibial nerve obviously increased in acupuncture treatment groups A and B after treatment (P < 0.05). MCV of ulnar nerve, MCV and SCV of common peroneal nerve and tibial nerve obviously increased more in acupuncture treatment group A than in acupuncture treatment group B (P < 0.05). At week 8 after treatment scores of HAMD and HAMA were obviously lowered in acupuncture groups A and B, with statistical difference as compared with before treatment (P < 0.05). The scores of HAMD were also decreased in the common treatment group, as compared with before treatment (P < 0.05). At week 8 after treatment scores of HAMD and HAMA were obviously lowered more in acupuncture treatment group B than in acupuncture treatment group A (P < 0.05). CONCLUSION: Acupuncture therapy could effectively improve the neurofunction of CAPN patients, and improve complicated anxiety and depression by additionally needling at Sishencong (EX-HN1), Yintang (EX-HN3), Taichong (LR3), Sanyinjiao (SP6), and Taiyang (EX-HN5).

Potential risk factors for the development of seroma following mastectomy with axillary dissection.

Seroma is a common complication following breast cancer surgery and the controllable predictive factors remain unknown. Patients who underwent mastectomy with axillary dissection between 2008 and 2011 in our hospital were retrospectively investigated. The demographics, clinical characteristics and therapeutic factors of each patient were recorded. The association of seroma incidence with each variable was evaluated by univariate logistic regression analysis. All the variables were considered independent predictors of seroma incidence. The probability of developing seroma following surgery was evaluated by multivariate logistic regression analysis. A total of 102 patients, with a mean age of 54.86±13.02 years (range, 30-89 years), were included in this study and the incidence of seroma was found to be 22.55%. The operative time (P=0.0066, coefficient = 0.0261, OR=1.03) and the use of patient-controlled intravenous analgesia (PCA) (P=0.0002, coefficient = -1.8089, OR=0.03, ref = no) was significantly associated with the incidence of seroma postoperatively. In conclusion, the prediction of the development of seroma following mastectomy with axillary dissection is challenging. However, a longer operative time and the non-use of PCA may represent potential risk factors for this complication.

Effects of repeated allopurinol administration on rat cytochrome P450 activity.

Allopurinol is a popular and widely-prescribed anti-hyperuricemic agent that has been implicated in drug interactions with substrates of several cytochrome P450 (CYP) enzymes. The effect of repeated allopurinol administration (20 mg/kg, once daily for 14 days) on metabolic activity of CYP was assessed in rats. This was a randomized, double-blind, two-way crossover study with a 4-week washout period between phases. The substrates used in this study were phenacetin (CYP1A2), tolbutamide (CYP2C9), omeprazole (CYP2C19) and dextromethorphan (CYP2D6). Validated HPLC-MS/MS was used to quantify all compounds. Our study showed that allopurinol administration inhibited CYP1A2 activity, causing a significant increase in AUC (0-infinity) (P < 0.01) and t1/2 (P < 0.05) of phenacetin, and a distinct decline in CL (P < 0.01). However, there were no significant differences of another three probe drugs in plasma concentrations and the corresponding pharmacokinetic parameters between the allopurinol-treated and normal saline-treated rats. The findings in this study suggested that allopurinol could inhibit CYP1A2 but did not influence CYP2C9, CYP2C19 and CYP2D6 enzymes.

Expression and clinical significance of osteopontin in calcified breast tissue.

Osteopontin (OPN) is an integrin-binding protein, believed to be involved in a variety of physiological cellular functions. The physiology of OPN is best documented in the bone where this secreted adhesive glycoprotein appears to be involved in osteoblast differentiation and bone formation. In our study, we used semi-quantitative RT-PCR of osteopontin in calcification tissue of breast to detect breast cancer metastasis. The obtained data indicate that the expression of osteopontin is related to calcification tissue of breast, and possibly with the incidence of breast cancer. The expression strength of OPN by RT-PCR detection was related to the degree of malignancy of breast lesions, suggesting a close relationship between OPN and breast calcification tissue. The results revealed that expression of OPN mRNA is related to calcification of breast cancer tissue and to the development of breast cancer. Determination of OPN mRNA expression can be expected to be a guide to clinical therapy and prediction of the prognosis of breast cancer patients.

[Efficacy observation of combination of Lumbrukinase Capsule and Probucol Tablet in treating cerebral infarction patients' unstable atheromatous plaque of the carotid artery].

OBJECTIVE: To observe the effects of combination of Lumbrukinase Capsule (LC) and Probucol Tablet (PT) in treating cerebral infarction (CI) patients' unstable atheromatous plaque of the carotid artery. METHODS: 150 patients were randomly assigned to the PT group and the LC group, 75 cases in each. Patients in the PT group took 0.5 g PT each time, twice daily. On the basis of PT, patients in the LC group also took 600 thousand U LC, thrice daily. The treatment course was 12 months for all. The serum levels of TC, TG, HDL-C, LDL-C, fibrinogen (FIB), and changes of the carotid atherosclerotic plaque were measured before treatment, 6 and 12 months after treatment. Meanwhile, adverse events were recorded. RESULTS: The serum levels of TC, TG, and LDL-C were all lower 6 months after treatment than before treatment in the two groups, showing statistical significance (P < 0.05). The serum level of HDL-C was higher 6 months after treatment than before treatment in the two groups, showing no statistical significance (P > 0.05). When compared with before treatment in the same group, the serum level of FIB significantly decreased after treatment. Besides, there was statistical difference between the two groups (P < 0.05). There was no statistical difference in the serum levels of blood lipids or FIB between 12-month treatment and 6-month treatment in the same group (P > 0.05). The plaque effective rate in the LC group was superior to that of the PT group, showing statistical significance (P < 0.01). During the treatment period, the occurrence of cerebrovascular event was lower in the LC group than in the PT group (P < 0.05). Partial patients in the two groups had gastric discomfort. CONCLUSIONS: The combination of LC and PT could prevent and treat arteriosclerosis, stabilize the plaque, effectively lower the occurrence of ischemic events. Its clinical application did not increase the risk of hemorrhage. It was safe and effective, worthy of spreading. It was necessary to further observe whether combination of LC and PT could increase side effects of the digestive tract.

[Research on iron in marshy rivers of the Sanjiang Plain].

River waters (including the main river and marshy river) were sampled to study the iron concentration, species and complexed competitive ability in the Sanjiang Plain in order to reveal the influence of wetland reclamation on the iron species and output flux. The cross-flow filtration technique was employed to separate iron species according to size fraction. The result showed that the typical marshy river which is rich in organic matters became an important iron source for atypical marshy river. In the typical marshy river, the concentration of total dissolved and acid-labile iron reached to 1.16 and 0.81 mg x L(-1), respectively. Complexed (accounting 70.9% of total dissolved iron) and ion iron (accounting 9.3% of total dissolved iron) were the primary species in dissolved iron. Therefore, iron transported primarily as low-molecular-weight iron forms in river waters in the Sanjiang Plain. The low-molecular-weight iron accounted for 68.7% and 82.2% of total dissolved iron and low-molecular-weight iron concentrations reached to 0.13 and 0.88 mg x L(-1) in the main and typical marshy river, respectively. The ferric iron concentration in the typical marshy river was 3.1 times higher than that in the atypical marshy river. Little difference of ferrous iron contents between the typical and atypical marshy river was observed. Fe(II) was found in complexed and colloidal iron through ligand competitive experiment. In the typical marshy river, complexed iron had a higher ligand competitive ability, which could form more stable complexed iron. The decline of the stable complexed iron output flux due to reclamation of the Sanjiang wetland would greatly influence the distance of iron transportation, especially iron output to the coastal waters.