Ferrocene-functionalized polydopamine film timely mediates M1-to-M2 macrophage polarization through adaptive wettability.

Dynamical control of macrophage polarization from M1 (pro-inflammatory) to M2 (anti-inflammatory) at implant surfaces is essential for balancing innate immunity and tissue repair. In this aspect, the design of orthopedic implant that can response to inflammation microenvironment with transformation in surface properties has shown promising in timely driving M1-to-M2 macrophage transition. Considering excessive reactive oxygen species (ROS) contribute to macrophage M1 polarization and progression of inflammation, in this study, ferrocene modified polydopamine (PDA-Fc) films were deposited on plasma sprayed Ti coatings to endow the implants with ROS-responsive and -scavenging abilities. Plasma sprayed Ti (PST) coating and PDA modified PST coating (PST/PDA) served as control. The presence of PDA endowed PST/PDA and PST/PDA-Fc with free-radical scavenging abilities. Moreover, PST/PDA-Fc showed adaptive wettability as evidenced by increased hydrophilicity under H2O2 treatment. With respect to PST/PDA, PST/PDA-Fc exerted greater effects on inducing lipopolysaccharides-induced M1 macrophages to adopt M2-type macrophage phenotype, characterized by higher percentage of CD206-positive cells, increased cell elongation rate and higher expression level of anti-inflammatory cytokine arginase type 1. The results obtained in our study may provide a prospective approach for manipulating an appropriate immune response at implant surfaces.

Serum triglyceride glucose index is a valuable predictor for visceral obesity in patients with type 2 diabetes: a cross-sectional study.

BACKGROUND: Since the triglyceride glucose (TyG) index can reflect insulin resistance, it has been proven to be an efficient predictor of glycolipid-metabolism-related diseases. Therefore, this study aimed to investigate the predictive value of the TyG index for visceral obesity (VO) and body fat distribution in patients with type 2 diabetes mellitus (T2DM). METHODS: Abdominal adipose tissue characteristics in patients with T2DM, including visceral adipose area (VAA), subcutaneous adipose area (SAA), VAA-to-SAA ratio (VSR), visceral adipose density (VAD), and subcutaneous adipose density (SAD), were obtained through analyses of computed tomography images at the lumbar 2/3 level. VO was diagnosed according to the VAA (> 142 cm2 for males and > 115 cm2 for females). Logistic regression was performed to identify independent factors of VO, and receiver operating characteristic (ROC) curves were used to compare the diagnostic performance according to the area under the ROC curve (AUC). RESULTS: A total of 976 patients were included in this study. VO patients showed significantly higher TyG values than non-VO patients in males (9.74 vs. 8.88) and females (9.59 vs. 9.01). The TyG index showed significant positive correlations with VAA, SAA, and VSR and negative correlations with VAD and SAD. The TyG index was an independent factor for VO in both males (odds ratio [OR] = 2.997) and females (OR = 2.233). The TyG index ranked second to body mass index (BMI) for predicting VO in male (AUC = 0.770) and female patients (AUC = 0.720). Patients with higher BMI and TyG index values showed a significantly higher risk of VO than the other patients. TyG-BMI, the combination index of TyG and BMI, showed significantly higher predictive power than BMI for VO in male patients (AUC = 0.879 and 0.835, respectively) but showed no significance when compared with BMI in female patients (AUC = 0.865 and 0.835, respectively). CONCLUSIONS: . TyG is a comprehensive indicator of adipose volume, density, and distribution in patients with T2DM and is a valuable predictor for VO in combination with anthropometric indices, such as BMI.

Association Between the Growth Hormone/Insulin-Like Growth Factor-1 Axis and Muscle Density in Children and Adolescents of Short Stature.

Objective: To evaluate the association between the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis and muscle density in children and adolescents of short stature. Methods: Participants were children and adolescents of short stature hospitalized in the Affiliated Hospital of Jining Medical University between January 2020 and June 2021. All participants had CT scan images available. We performed an analysis of the images to calculate the muscle density or skeletal muscle attenuation (SMA), skeletal muscle index (SMI), and fat mass index (FMI). Bioelectrical impedance analysis (BIA) was used to ensure that chest CT is a credible way of evaluating body composition. Results: A total of 297 subjects were included with the mean age of 10.00 ± 3.42 years, mean height standard deviation score (SDS) of -2.51 ± 0.53, and mean IGF-1 SDS of -0.60 ± 1.07. The areas of muscle and fat tissues at the fourth thoracic vertebra level in the CT images showed strong correlation with the total weights of the participants (R2  = 0.884 and 0.897, respectively). The peak of GH was negatively associated with FMI (r = - 0.323, P <.01) and IGF-1 SDS was positively associated with SMI (r = 0.303, P <.01). Both the peak GH and IGF-1 SDS were positively associated with SMA (r = 0.244, P <.01 and r = 0.165, P <.05, respectively). Multiple stepwise linear regression analysis demonstrated that the GH peak was the predictor of FMI (ß = - 0.210, P < .01), the IGF-1 SDS was the predictor of SMI (ß = 0.224, P < .01), and both the peak GH and IGF-1 SDS were predictors of SMA (ß = 0.180, P < .01 and ß = 0.222, P < .01). Conclusions: A chest CT scan is a credible method of evaluating body composition in children and adolescents of short stature. In these patients, peak GH and IGF-1 SDS are independent predictors of muscle density and the GF/IGF-1 axis may regulate body composition through complex mechanisms.

The effects of glucagon-like peptide-1 receptor agonists on adipose tissues in patients with type 2 diabetes: A meta-analysis of randomised controlled trials.

AIMS: Glucagon­like peptide 1 receptor agonist (GLP-1RA) treatment can improve adipose distribution. We performed this meta-analysis to investigate whether GLP-1RAs preferentially reduce visceral adipose tissue (VAT) over subcutaneous adipose tissue (SAT) in patients with type 2 diabetes. MATERIALS AND METHODS: We searched MEDLINE and the Cochrane Library for randomised controlled trials explicitly reporting changes in VAT and SAT. A random-effects model was performed to estimate the weighted mean difference (MD) for VAT and SAT. Heterogeneity among the studies was assessed using I2 statistics, and publication bias was assessed using Egger's tests. Meta-regression was performed to identify the correlation between changes in adipose tissues and changes in body weight and glycated haemoglobin level. RESULTS: Ten trials with 924 patients were enrolled in the meta-analysis. GLP-1RA treatment led to similar absolute area (cm2) reductions in VAT (MD -21.13 cm2, 95% CI [-29.82, -12.44]) and SAT (MD -22.89 cm2, 95% CI [-29.83, -15.95]). No significant publication bias was detected, and this result was stable in the sensitivity and subgroup analyses. Moreover, GLP-1RA treatment resulted in a greater reduction in VAT and SAT in the subgroup with a greater reduction in body weight. The absolute area reduction in VAT was significantly correlated with the reduction in body weight (r = 6.324, p = 0.035). CONCLUSIONS: GLP-1RA treatment leads to significant and similar absolute reductions in VAT and SAT, and the reduction in adipose tissues may be correlated with the reduction in body weight.

Highly Thermal Conductive Graphite Films Derived from the Graphitization of Chemically Imidized Polyimide Films.

With the large-scale application and high-speed operation of electronic equipment, the thermal diffusion problem presents an increasing requirement for effective heat dissipation materials. Herein, high thermal conductive graphite films were fabricated via the graphitization of polyimide (PI) films with different amounts of chemical catalytic reagent. The results showed that chemically imidized PI (CIPI) films exhibit a higher tensile strength, thermal stability, and imidization degree than that of purely thermally imidized PI (TIPI) films. The graphite films derived from CIPI films present a more complete crystal orientation and ordered arrangement. With only 0.72% chemical catalytic reagent, the graphitized CIPI film achieved a high thermal conductivity of 1767 W·m-1·K-1, which is much higher than that of graphited TIPI film (1331 W·m-1·K-1), with an increase of 32.8%. The high thermal conductivity is attributed to the large in-plane crystallite size and high crystal integrity. It is believed that the chemical imidization method prioritizes the preparation of high-quality PI films and helps graphite films achieve an excellent performance.

Aqueous Organic Zinc-Ion Hybrid Supercapacitors Prepared by 3D Vertically Aligned Graphene-Polydopamine Composite Electrode.

A three-dimensional vertical-aligned graphene-polydopamine electrode (PDA@3DVAG) composite with vertical channels and conductive network is prepared by a method of unidirectional freezing and subsequent self-polymerization. When the prepared PDA@3DVAG is constructed as the positive electrode of zinc-ion hybrid supercapacitors (ZHSCs), excellent electrochemical performances are obtained. Compared with the conventional electrolyte, PDA@3DVAG composite electrode in highly concentrated salt electrolyte exhibits better multiplicity performance (48.92% at a current density of 3 A g-1), wider voltage window (-0.8~0.8 V), better cycle performance with specific capacitance from 96.7 to 59.8 F g-1, and higher energy density (46.14 Wh kg-1).

Preparation and Electrochemical Performance of Three-Dimensional Vertically Aligned Graphene by Unidirectional Freezing Method.

Three-dimensional vertically aligned graphene (3DVAG) was prepared by a unidirectional freezing method, and its electrochemical performances were evaluated as electrode materials for zinc-ion hybrid supercapacitors (ZHSCs). The prepared 3DVAG has a vertically ordered channel structure with a diameter of about 20-30 µm and a length stretching about hundreds of microns. Compared with the random structure of reduced graphene oxide (3DrGO), the vertical structure of 3DVAG in a three-electrode system showed higher specific capacitance, faster ion diffusion, and better rate performance. The specific capacitance of 3DVAG reached 66.6 F·g-1 and the rate performance reached 92.2%. The constructed 3DVAG zinc-ion hybrid supercapacitor also showed excellent electrochemical performance. It showed good capacitance retention up to 94.6% after 3000 cycles at the current density of 2 A·g-1.

Preparation of Nitrogen-Doped Cellulose-Based Porous Carbon and Its Carbon Dioxide Adsorption Properties.

Nitrogen-doped cellulose-based porous carbon materials were obtained by hydrothermal method and KOH chemical activation together with melamine as a nitrogen-doping precursor. The effects of hydrothermal temperature on the microstructure and surface morphology of the products were mainly studied. Also, the carbon dioxide adsorption capacity of the prepared porous carbon was investigated. It was found that when the hydrothermal carbonization temperature was 270 °C and the mass ratio of cellulose and melamine was 1:1, the largest micropore specific surface area of 1703 m2·g-1 and micropore volume of 0.65 cm3·g-1 were obtained, with a nitrogen-doping composition of 1.68 atom %. At the temperature of 25 °C and under the pressure of 0.1, 0.2, 0.3, and 0.4 MPa, the adsorption amount of CO2 was 1.56, 3.79, 5.42, and 7.34 mmol·g-1, respectively. Also, the adsorption process of CO2 was in good accordance with the Freundlich isotherm model.

A Simple Method of Evaluating the Thermal Properties of Metallurgical Cokes under High Temperature.

The reactivity index of weight loss (RI) and tumbling strength after the reaction (I10600) of manufacturing coke were first tested at a temperature series of 1100, 1200, and 1300 °C under CO2 atmosphere with different compositions and duration times to study the effects of temperature, time, and gas composition on coke hot strength. Then the RI/I10600, carbon structure, and optical texture of the cokes prepared from different single coals were mainly studied after a solution reaction with CO2 under a high temperature of 1300 °C and a standard temperature of 1100 °C. It was found that temperature greatly affects the RI/I10600 of coke, especially at high temperatures up to 1300 °C. Compared with standard tests under 1100 °C, the changes of RI/I10600 for different cokes are very different at 1300 °C, and the changes are greatly related to coke optical texture. Under a high temperature in the testing method, the tumbling strength of cokes with more isotropy increased, whereas it decreased for those with less isotropy. This simple method of using high temperature could yield the same results when compared with complicated simulated blast furnace conditions.

A missense variant rs2585405 in clock gene PER1 is associated with the increased risk of noise-induced hearing loss in a Chinese occupational population.

OBJECTIVE: To investigate the potential association of cochlear clock genes (CRY1, CRY2, PER1, and PER2), the DNF gene (brain-derived neurotrophic factor), and the NTF3 gene (neurotrophin3) with susceptivity to noise-induced hearing loss (NIHL) among Chinese noise-exposed workers. METHODS: A nested case-control study was performed with 2056 noise-exposed workers from a chemical fiber factory and an energy company who underwent occupational health examinations in 2019 as study subjects. Propensity score matching was conducted to screen cases and controls by matching sex, age, and the consumption of tobacco and alcohol. A total of 1269 participants were enrolled. Then, general information and noise exposure of the study subjects were obtained through a questionnaire survey and on-site noise detection. According to the results of audiological evaluations, the participants were divided into the case group (n = 432, high-frequency threshold shift > 25 dB) and the matched control group (n = 837, high-frequency threshold shift ≤ 25 dB) by propensity score matching. Genotyping for PER1 rs2253820 and rs2585405; PER2 rs56386336 and rs934945; CRY1 rs1056560 and rs3809236; CRY2 rs2292910 and rs6798; BDNF rs11030099, rs7124442 and rs6265; and NTF3 rs1805149 was conducted using the TaqMan-PCR technique. RESULTS: In the dominant model and the co-dominant model, the distribution of PER1 rs2585405 genotypes between the case group and the control group was significantly different (P = 0.03, P = 0.01). The NIHL risk of the subjects with the GC genotype was 1.41 times the risk of those carrying the GG genotype (95% confidence interval (CI) of odds ratio (OR): 1.01-1.96), and the NIHL risk of the subjects with the CC genotype was 0.93 times the risk of those carrying the GG genotype (95%CI of OR: 0.71-1.21). After the noise exposure period and noise exposure intensities were stratified, in the co-dominant model, the adjusted OR values for noise intensities of ≤ 85 was 1.23 (95%CI: 0.99-1.53). In the dominant model, the adjusted OR values for noise exposure periods of ≤ 16 years and noise intensities of ≤ 85 were 1.88 (95%CI: 1.03-3.42) and 1.64 (95%CI: 1.12-2.38), respectively. CONCLUSION: The CC/CG genotype of rs2585405 in the PER1 gene was identified as a potential risk factor for NIHL in Chinese noise-exposed workers, and interaction between rs2585405 and high temperature was found to be associated with NIHL risk.

Preparation and Electrical Properties of Polyacrylonitrile Based Porous Carbon by Different Activation Methods.

Polyacrylonitrile (PAN)-based porous carbon was prepared by different methods of activation with PAN polymer microsphere as precursor. The morphology, structure and electrical properties for supercapacitor of the porous carbon were investigated. It was found that the morphology of PAN nanospheres tended to be destroyed in the process of one-step activation (activation and carbonization were carried out simultaneously, and could only be retained when the amount of activating agent KOH was small). While the spherical morphology could be well reserved during the two-step activation method (carbonization and activation sequentially). The specific surface area and pore volume increased first and then decreased, with the increase in activation holding time for both one-step and two-step activation methods. The specific surface area reached the maximum value with 2430 m2 g-1 for the one-step activation method and 2830 m2 g-1 for the two-step activation method. Additionally, their mass-specific capacitances were 178.8 F g-1 and 160.2 F g-1, respectively, under the current density of 1 A g-1. After 2000 cycles, the specific capacitance retentions were 92.9% and 91.3%.

Genetic association study between TAB2 polymorphisms and noise-induced-hearing-loss in a Han Chinese population.

Noise-induced-hearing-loss(NIHL) is a common occupational disease caused by various environmental and biological factors. To investigate the association between TAB2 and the susceptibility of NIHL of people exposed to occupational environments, a genetic association study was performed on selected companies with 588 cases and 537 healthy control subjects. Five selected single nucleotide polymorphisms (SNPs) in TAB2,incoluding rs2744434, rs521845, rs652921, rs7896, rs9485372, were genotyped after a collection of DNA samples. Evident differences in participants between the case group and the control group reveals the result that people with the TAB2 has a high probability of getting NIHL. The results show that rs521845 is deeply associated with the risk of NIHL and is available for the diagnosis in the future.

Highly sensitive determination of cadmium and lead in whole blood by electrothermal vaporization-atmospheric pressure glow discharge atomic emission spectrometry.

In this study, a fast and simple method for highly sensitive detection of Cd and Pb elements based on atmospheric pressure glow discharge atomic emission spectrometry (APGD-AES) coupling with tungsten coil electrothermal vaporization (ETV) was proposed. A small amount of sample (10 µL) was dropped onto the tungsten coil, followed by drying, pyrolysis and vaporization procedures, and then the vaporized analyte was transported to APGD for excitation. The whole procedure took approximately 3 min. Multi-step heating of the ETV unit can separate matrices and solvents from the analyte, providing an advantage in detecting samples with complex matrix. Under the optimal experimental conditions, limits of detection of 0.4 µg L-1 (4 pg) for cadmium and 1.2 µg L-1 (12 pg) for lead were obtained, with relative standard deviations of 20 µg L-1 Cd and 100 µg L-1 Pb both being <5%. The accuracy of the ETV-APGD-AES system was verified by the determination of heavy metals in whole blood standard sample (GBW(E)090,251) and the practicability of the ETV-APGD-AES system were demonstrated by the determination of heavy metals in human whole blood. The results obtained by this instrument agree well with the standard values and those obtained by ICP-MS.

Histone deacetylase 2 polymorphisms associated with noise-induced hearing loss in Chinese workers.

Noise-induced hearing loss (NIHL) is one of these hazards which has been the second most common sensorineural hearing loss. Single-nucleotide polymorphisms (SNPs) mainly refer to the polymorphism of DNA sequence caused by the variation at the genomic nucleotide level. The influence of histone deacetylase 2 (HDAC2) variants on the risk of NIHL has not been studied. This research explored the association between HDAC2 and the development of NIHL. A total of 1146 industrial workers from one textile factory in east China were recruited to perform a case-control study. Basic clinical data such sex, age, smoking, and drinking was obtained by questionnaires; pure-toneaudiometry (PTA) tests were conducted by specialist physicians. Then, we performed genotyping of five selected SNPs (rs10499080, rs2475631, rs2499618, rs6568819, and rs3757016) in the HDAC2 gene in 600 NIHL patients and 546 controls. Finally, the main influences of the SNPs and their interactions with NIHL were assessed. Under the recessive model, there were statistically significant differences in the genotype frequencies of rs10499080 between two groups, and the results showed that individuals with rs10499080 CC+CT had a lower risk of NIHL (OR = 0.597, 95%CI = 0.357-0.998). Meanwhile, the significant difference in the genotype distributions between cases and controls was found in rs10499080 in the group with noise exposure of ≤ 16 years. But the following haplotype analysis showed that no association between all haplotypes in the HDAC2 gene and NIHL was been found. The genetic polymorphisms rs10499080 and rs6568819 within HDAC2 gene have an association with risk of NIHL. Workers exposed to noise with HDAC2 have a lower risk of NIHL.

Bifunctional Fluorinated Separator Enabling Polysulfide Trapping and Li Deposition for Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSBs) are deemed as one of the most promising next generation energy storage system substitutes for conventional lithium ion batteries due to their high energy density, low cost, and environmental friendliness. The practical application of LSBs has long been blocked by the serious lithium polysulfide (LiPS) shuttle effect and notorious Li dendrite growth, inducing fast capacity decay and limited cycling lifespan. Herein, fluorinated carbon prepared via a safe and scalable strategy has rationally been coated on a separator affording bifunctional fluorinated Celgard (F-Celgard) for LSB construction. The F-Celgard shows superior Li+ flux modulation and LiPS trapping capability, which has been verified by the density function theory calculations. The Li symmetric cells demonstrate long and stable Li plating/stripping with much smaller polarization voltage and dendrite-free Li deposition. In addition, LSBs show superior rate performances with higher discharge capacities and long-time stable cycling over 1000 cycles at 1 C with a low decay rate of ∼0.038% per cycle. With a high sulfur loading (∼5.2 mg cm-2), a high initial areal capacity of ∼4.2 mAh cm-2 can be obtained with a superior capacity retention of ∼91.8% at 0.2 C. This work demonstrates a facile, cost-effective, and scalable strategy toward highly stable LSBs for practical usage.

Analysis of Cuttings' Minerals for Multistage Hydraulic Fracturing Optimization in Volcanic Rocks.

The fracturing of naturally fractured volcanic rocks has a significant impact on the logging due to the high degree of volcanic fracture development and the complex distribution of fractures. Such impact ultimately leads to the difficulty in determining the location of fracturing perforations and the increase in engineering costs. This article proposed a method of analyzing cuttings for geologging that return to the ground when drilling. After cleaning and further processing of the cuttings, samples at every depth are formed. Then, an electron microscope and supporting processing software are used to calculate the parameters of the sample at each depth and the rock mechanical parameters in the target well section based on the mineral content. Compared with mud logging data, the mineral analysis method of rock cuttings costs less time, and the materials are easier to obtain, thereby providing richer data. This method has an important guiding role for the selection of perforation positions in large-scale hydraulic fracturing.

A novel collision tumour of myofibroblastoma and low-grade adenosquamous carcinoma in breast.

BACKGROUND: Myofibroblastoma (MFB) and low-grade adenosquamous carcinoma (LGASC) are rare tumours in the breast, respectively. However, a collision tumour of the two types has never been reported. CASE PRESENTATION: A 42-year-old female presented with a palpable mass in diameter of about 2.5 cm in the left breast. Morphologically, the lesion was predominately composed of bland spindle cells admixed with some islands of mature adipocytes and a few epithelial elements dispersing in infiltrating way which formed both tubule and solid structures. The mass showed low positive index of Ki-67. The spindle cells were strongly and diffusely positive for CD34, SMA, desmin, ER and PR. The epithelial elements were positive for CK and EMA, and negative for ER and PR completely. CK5/6 and P63 were positive in the outer-layer of the tubules and nearly all the cells of the solid nests. CONCLUSIONS: A collision tumour of MFB and LGASC in breast is extremely rare and either component is supposed to be not overlooked. Excision and close follow-up are advised.

Granular Cell Tumor of the Neurohypophysis With TFE-3 Expression: A Rare Case Report.

Granular cell tumor (GCT) rarely involves the central nervous system, and fewer than 100 cases have been reported in English literatures. We herein report a case of a 36-year-old Chinese man with GCT of the neurohypophysis. Magnetic resonance imaging showed one mass located in the hypophysis with heterogeneous contrast enhancement. Pathological examination showed a neoplasm comprising densely packed polygonal cells of ample cytoplasm with abundant eosinophilic granules inside. The nuclei were small with inconspicuous nucleoli and yet without any mitoses. The tumor was positive for S-100, CD68, CD163, lysosome, and vimentin. Translocation factor E-3 (TFE-3) was diffusely nuclear positive although ASPSCR1-TFE-3 fusion was not detected by fluorescence in situ hybridization. GCT of the neurohypophysis is supposed to be considered under differential diagnosis with neoplasms or lesions of histiocytic origin and others such as pituitocytoma and spindle cell oncocytoma. A group of markers such as GFAP, EMA, CD68, S-100, and PAS staining are useful in complementary diagnosis and TFE-3 may be an alternative marker.

Nanosized sustained-release drug depots fabricated using modified tri-axial electrospinning.

Nanoscale drug depots, comprising a drug reservoir surrounded by a carrier membrane, are much sought after in contemporary pharmaceutical research. Using cellulose acetate (CA) as a filament-forming polymeric matrix and ferulic acid (FA) as a model drug, nanoscale drug depots in the form of core-shell fibers were designed and fabricated using a modified tri-axial electrospinning process. This employed a solvent mixture as the outer working fluid, as a result of which a robust and continuous preparation process could be achieved. The fiber-based depots had a linear morphology, smooth surfaces, and an average diameter of 0.62±0.07µm. Electron microscopy data showed them to have clear core-shell structures, with the FA encapsulated inside a CA shell. X-ray diffraction and IR spectroscopy results verified that FA was present in the crystalline physical form. In vitro dissolution tests revealed that the fibers were able to provide close to zero-order release over 36h, with no initial burst release and minimal tailing-off. The release properties of the depot systems were much improved over monolithic CA/FA fibers, which exhibited a significant burst release and also considerable tailing-off at the end of the release experiment. Here we thus demonstrate the concept of using modified tri-axial electrospinning to design and develop new types of heterogeneous nanoscale biomaterials. STATEMENT OF SIGNIFICANCE: Nanoscale drug depots with a drug reservoir surrounded by a carrier are highly attractive in biomedicine. A cellulose acetate based drug depot was investigated in detail, starting with the design of the nanostructure, and moving through its fabrication using a modified tri-axial electrospinning process and a series of characterizations. The core-shell fiber-based drug depots can provide a more sustained release profile with no initial burst effect and less tailing-off than equivalent monolithic drug-loaded fibers. The drug release mechanisms are also distinct in the two systems. This proof-of-concept work can be further expanded to conceive a series of new structural biomaterials with improved or new functional performance.

Epitaxial Growth of Aligned and Continuous Carbon Nanofibers from Carbon Nanotubes.

Exploiting the superior properties of nanomaterials at macroscopic scale is a key issue of nanoscience. Different from the integration strategy, "additive synthesis" of macroscopic structures from nanomaterial templates may be a promising choice. In this paper, we report the epitaxial growth of aligned, continuous, and catalyst-free carbon nanofiber thin films from carbon nanotube films. The fabrication process includes thickening of continuous carbon nanotube films by gas-phase pyrolytic carbon deposition and further graphitization of the carbon layer by high-temperature treatment. As-fabricated nanofibers in the film have an "annual ring" cross-section, with a carbon nanotube core and a graphitic periphery, indicating the templated growth mechanism. The absence of a distinct interface between the carbon nanotube template and the graphitic periphery further implies the epitaxial growth mechanism of the fiber. The mechanically robust thin film with tunable fiber diameters from tens of nanometers to several micrometers possesses low density, high electrical conductivity, and high thermal conductivity. Further extension of this fabrication method to enhance carbon nanotube yarns is also demonstrated, resulting in yarns with ∼4-fold increased tensile strength and ∼10-fold increased Young's modulus. The aligned and continuous features of the films together with their outstanding physical and chemical properties would certainly promote the large-scale applications of carbon nanofibers.