Environmentally relevant concentrations of microplastics from agricultural mulch and cadmium negatively impact earthworms by triggering neurotoxicity and disrupting homeostasis.

Recent research has highlighted the ecological risk posed by microplastics (MPs) from mulching film and heavy metals to soil organisms. However, most studies overlooked real environmental levels of MPs and heavy metals. To address this gap, pristine and aged polyethylene (PE) mulching film-derived MPs (PMPs, 500 mg/kg; AMPs, 500 mg/kg) were combined with cadmium (Cd, 0.5 mg/kg) to assess the acute toxicity to earthworms and investigate associated molecular mechanisms (oxidative stress, osmoregulation pressure, gut microbiota, and metabolic responses) at environmentally relevant concentrations. Compared to Cd alone and Cd + PMPs treatments (11.15 ± 4.19 items/g), Cd + AMPs treatment resulted in higher MPs bioaccumulation (23.73 ± 13.14 items/g), more severe tissue lesions, and increased cell membrane osmotic pressure in earthworms' intestines. Cd + AMPs induced neurotoxicity through elevated levels of glutamate and acetylcholinesterase. Earthworm intestines (0.98 ± 0.49 to 3.33 ± 0.37 mg/kg) exhibited significantly higher Cd content than soils (0.19 ± 0.01 to 0.51 ± 0.06 mg/kg) and casts (0.15 ± 0.01 to 0.25 ± 0.05 mg/kg), indicating PE-MPs facilitated Cd transport in earthworms' bodies. Metabolomic analysis showed Cd + AMPs exposure depleted energy and nucleotide metabolites, disrupted cell homeostasis more profoundly than Cd and Cd + PMPs treatments. Overall, co-exposure to AMPs + Cd induced more severe neurotoxicity and disruption of homeostasis in earthworm than Cd and PMPs + Cd treatments. Our study, using Cd and MPs with environmental relevance, underscores MPs' role in amplifying Cd accumulation and toxicity in earthworms.

Chlorine dioxide inactivation of enterovirus 71 in water and its impact on genomic targets.

To control the waterborne transmission of enterovirus 71(EV71), which is associated with hand foot and mouth disease (HFMD), it is essential to know the inactivation effectiveness of disinfectants on EV71 in water. In this article, we present a comparative analysis of the effects on EV71 following exposure to chlorine dioxide (ClO2) under different doses, pH, and temperature conditions. We show that the EV71 exhibited strong resistance to ClO2 (more than the MS2 standard) and that Ct value ranges required for a 4-log reduction of EV71 in buffered, disinfectant demand-free water at pH 7.2 and 20 °C by ClO2 were 4.24-6.62 mg/L·min according to the efficiency factor Hom model. ClO2 inactivation of the virus was temperature- and pH-dependent. The virucidal efficiency was higher at pH 8.2 than at pH 5.6 and pH 7.2 and higher at 36 °C than at 4 and 20 °C. In addition, we also observed the impact of ClO2 on the entire viral genome using RT-PCR, which indicated that the 5' noncoding region (5'-NCR) within the EV71 genome, specifically the 1-118 nt region, was the most easily damaged by ClO2 and correlated with viral infectivity. Our study has not only provided guidelines for EV71 disinfection strategies of waste and drinking water, but also confirmed the importance of the 5'-NCR for EV71 infectivity and may demonstrate a general inactivation by ClO2 of enteric virus by damaging the 5'-NCR. Furthermore, 5'-NCR can be used as a target region for PCR to investigate infectious virus contamination in environmental water and evaluate the inactivation effects of ClO2.

Comparison of titanium and polyetheretherketone (PEEK) cages in the surgical treatment of multilevel cervical spondylotic myelopathy: a prospective, randomized, control study with over 7-year follow-up.

PURPOSE: Anterior cervical discectomy and fusion (ACDF) with titanium- or polyetheretherketone (PEEK)-cage reconstruction is widely used in the treatment of cervical spondylotic myelopathy (CSM). This study was to compare outcomes of titanium and PEEK cages in the treatment of multilevel CSM. METHODS: Between November 2002 and December 2004, a total of 80 patients with 3-level CSM were randomized in a 1:1 ratio to titanium group and PEEK group. The overall follow-up period of the patients ranged from 86 to 116 months (average 99.7 months). Clinical and radiological results were compared between titanium group and PEEK group. RESULTS: At the final follow-up, the clinical outcomes including JOA score, NDI score, and the excellent and good rates of clinical outcomes in the PEEK group were better than those in the titanium group. More loss of the Cobb angles and the intervertebral height was observed in the titanium group, resulting in the radiological parameters in the titanium group becoming inferior to the PEEK group at the final follow-up. Cage subsidence rates were 34.5 and 5.4% in the titanium and PEEK groups, respectively. Fusion was observed in all patients of two groups at the final follow-up. Two patients presented with cage dislocation without clinical symptoms in the titanium group. CONCLUSIONS: In surgical treatment of multilevel CSM, PEEK cage is superior to titanium cage in maintenance of intervertebral height and cervical lordosis, resulting in better clinical outcomes in the long-term follow-up.

Application of PLGA/type I collagen/chitosan artificial composite dura mater in the treatment of dural injury.

To improve the safety of dura repair in neurological surgeries, a new poly (glycolide-co-lactide)/type I collagen/chitosan artificial composite dura mater was evaluated in a rabbit model with dura mater injury. Eighteen rabbits were randomized to 3 groups: rabbits with unclosed dura mater; rabbits with dura mater repaired by fascia and rabbits with dura mater repaired by the composite membrane. Modified combine behavior score were given at a series of time points and several cytokines were also determined to reflect the inflammatory conditions. Rabbits whose dura mater was repaired by composite membrane showed a similar recovery rate of neurological function and inflammatory condition compared with the rabbits whose dura mater was repaired by fascia. In addition, the rabbits with closed dura mater were better than ones with unclosed dura mater in the restore rate of neurological function as well as inflammatory reactions according to the statistical analysis. The new artificial membrane appears to be safe and efficient in the treatment of dura mater defect.

Supramolecular assemblies of multifunctional microgels for biomedical applications.

Biomedical materials with outstanding biochemical and mechanical properties have great potential in tissue engineering, drug delivery, antibacterial, and implantable devices. Hydrogels have emerged as a most promising family of biomedical materials because of their high water content, low modulus, biomimetic network structures, and versatile biofunctionalities. It is critical to design and synthesize biomimetic and biofunctional hydrogels to meet demands of biomedical applications. Moreover, fabrication of hydrogel-based biomedical devices and scaffolds remains a great challenge, largely due to the poor processibility of the crosslinked networks. Supramolecular microgels have emerged as building blocks for fabrication of biofunctional materials for biomedical applications due to their excellent characteristics, including softness, micron size, high porosity, heterogeneity and degradability. Moreover, microgels can serve as vehicles to carry drugs, bio-factors, and even cells to augment the biofunctionalities to support or regulate cell growth and tissue regeneration. This review article summarizes the fabrication and the mechanism of supramolecular assemblies of microgels, and explores their application in 3D printing, along with detailed representative biomedical applications of microgel assemblies in cell culture, drug delivery, antibacterial and tissue engineering. Major challenges and perspectives of supramolecular microgel assemblies are presented to indicate future research directions.

Delivery of Methoprene-Tolerant dsRNA to Improve RNAi Efficiency by Modified Liposomes for Pest Control.

The application of RNA interference (RNAi) technology for pest control is environmentally friendly and accurate. However, the efficiency of RNAi is often inconsistent and unreliable, and finding a suitable carrier element is considered critical to success in overcoming biotic and abiotic barriers to reach the target site. The fall armyworm, Spodoptera frugiperda (FAW), which is one of most important global agricultural pests, has recently spread rapidly to other parts of the world. In this study, a method to improve the stability and RNAi efficiency of the dsRNA carrier complex was reported. Methoprene-tolerant gene (Met) was selected as a target, a gene which is critical to the growth and development of FAW. Biomaterials nanoliposomes (LNPs) were modified with polyethylenimine (PEI) to deliver the dsRNA of Met. The synthesized Met3@PEI@LNPs reached a size of 385 nm and were found to load dsRNA effectively. Through stability and protection assays, it was found that LNPs provided reliable protection. In addition, the release curve also demonstrated that LNPs were able to prevent premature release under alkaline condition of the insect midgut but accelerate the release after entering the acidic environment of the target cells. The cell transfection efficiency of the prepared LNPs reached 96.4%. Toxicity tests showed that the use of LNPs could significantly improve the interference efficiency, with 91.7% interference efficiency achieved when the concentration of dsRNA in LNPs was only 25% of that of the control. Successful interference of Met demonstrated it could significantly shorten the larval period and make the larvae pupate earlier, thus achieving the purpose of control. In this study, we have demonstrated the use of nanotechnology to provide a novel RNAi delivery method for pest control.

3D printed microstructured ultra-sensitive pressure sensors based on microgel-reinforced double network hydrogels for biomechanical applications.

Hydrogel-based wearable flexible pressure sensors have great promise in human health and motion monitoring. However, it remains a great challenge to significantly improve the toughness, sensitivity and stability of hydrogel sensors. Here, we demonstrate the fabrication of hierarchically structured hydrogel sensors by 3D printing microgel-reinforced double network (MRDN) hydrogels to achieve both very high sensitivity and mechanical toughness. Polyelectrolyte microgels are used as building blocks, which are interpenetrated with a second network, to construct super tough hydrogels. The obtained hydrogels show a tensile strength of 1.61 MPa, and a fracture toughness of 5.08 MJ m-3 with high water content. The MRDN hydrogel precursors exhibit reversible gel-sol transitions, and serve as ideal inks for 3D printing microstructured sensor arrays with high fidelity and precision. The microstructured hydrogel sensors show an ultra-high sensitivity of 0.925 kPa-1, more than 50 times that of plain hydrogel sensors. The hydrogel sensors are assembled as an array onto a shoe-pad to monitor foot biomechanics during gaiting. Moreover, a sensor array with a well-arranged spatial distribution of sensor pixels with different microstructures and sensitivities is fabricated to track the trajectory of a crawling tortoise. Such hydrogel sensors have promising application in flexible wearable electronic devices.

Role of surface physicochemical properties of pipe materials on bio-clogging in leachate collection systems from a thermodynamic perspective.

Bio-clogging in pipes poses a significant threat to the operation of leachate collection systems. Bio-clogging formation is influenced by the pipe materials. However, the relationship between bio-clogging and the physicochemical properties of different pipe materials has not been clarified yet, especially from a thermodynamic aspect. In this study, the dynamic bio-clogging processes in pipes of different materials (high-density polyethylene (HDPE), polyvinyl chloride (PVC), polypropylene (PP), and polyethylene (PE)) were compared, and their correlation with the physicochemical properties was investigated. Results showed that the bio-clogging in HDPE and PVC pipes was more severe than that in PP and PE pipes. In bio-clogging development, the predominant factor changed from the surface roughness to the electron donator parameter (γ-). In the initial phase, the most severe bio-clogging was observed in the HDPE pipe, which exhibited the highest roughness (432 ± 76 nm). In the later phase, the highest γ- (2.2 mJ/m2) and protein content (2623.1 ± 33.2 µg/cm2) were observed in the PVC simultaneously. Moreover, the interaction energy indicated that the bacteria could irreversibly and reversibly adhere to the HDPE, whereas irreversible adhesion was observed in the PVC, PP, and PE cases. The findings clarify the thermodynamic mechanism underlying bio-clogging behaviors and provide novel insights into the bio-clogging behaviors in pipes of different materials, which can facilitate the development of effective bio-clogging control strategies.

Presence of microplastics alone and co-existence with hydrochar unexpectedly mitigate ammonia volatilization from rice paddy soil and affect structure of soil microbiome.

Microplastics (MPs), as an emerging pollutant, may cause deleterious changes to the nitrogen cycle in terrestrial ecosystems. However, single impact of MPs and synergistic effects of MPs with hydrochar on ammonia (NH3) volatilization and soil microbiome in paddy fields has been largely unexplored. In this study, polyethylene (PE), polyacrylonitrile (PAN) and straw-derived hydrochar (HBC) were selected for observations in an entire rice cycle growth period. Results showed that under the condition of 0.5% (w/w) MPs concentration, presence of MPs alone and co-existence of MPs and HBC (MPs + HBC) unexpectedly mitigated cumulative NH3 volatilization from paddy soil compared with the control with no MPs or HBC addition. MPs + HBC increased NH3 volatilization by 37.8-46.2% compared with MPs alone, indicating that co-existence of MPs and HBC weaken the mitigation effect of MPs on NH3 volatilization. Additionally, results of nitrogen cycle related microorganisms closely related to NH3 volatilization demonstrated that MPs + HBC altered the bacterial community structure and species diversity. These findings provide an important opportunity to advance our understanding of the impacts of MPs in agricultural environment and soils, and provide a sound theoretical basis for rationalizing the application of HBC in soil with MPs.

Rapid Surface Display of mRNA Antigens by Bacteria-Derived Outer Membrane Vesicles for a Personalized Tumor Vaccine.

Therapeutic mRNA vaccination is an attractive approach to trigger antitumor immunity. However, the mRNA delivery technology for customized tumor vaccine is still limited. In this work, bacteria-derived outer membrane vesicles (OMVs) are employed as an mRNA delivery platform by genetically engineering with surface decoration of RNA binding protein, L7Ae, and lysosomal escape protein, listeriolysin O (OMV-LL). OMV-LL can rapidly adsorb box C/D sequence-labelled mRNA antigens through L7Ae binding (OMV-LL-mRNA) and deliver them into dendritic cells (DCs), following by the cross-presentation via listeriolysin O-mediated endosomal escape. OMV-LL-mRNA significantly inhibits melanoma progression and elicits 37.5% complete regression in a colon cancer model. OMV-LL-mRNA induces a long-term immune memory and protects the mice from tumor challenge after 60 days. In summary, this platform provides a delivery technology distinct from lipid nanoparticles (LNPs) for personalized mRNA tumor vaccination, and with a "Plug-and-Display" strategy that enables its versatile application in mRNA vaccines.

Engineered Bacterial Outer Membrane Vesicles as Controllable Two-Way Adaptors to Activate Macrophage Phagocytosis for Improved Tumor Immunotherapy.

The most immune cells infiltrating tumor microenvironment (TME), tumor-associated macrophages (TAMs) closely resemble immunosuppressive M2-polarized macrophages. Moreover, tumor cells exhibit high expression of CD47 "don't eat me" signal, which obstructs macrophage phagocytosis. The precise and efficient activation of TAMs is a promising approach to tumor immunotherapy; however, re-education of macrophages remains a challenge. Bacteria-derived outer membrane vesicles (OMVs) are highly immunogenic nanovesicles that can robustly stimulate macrophages. Here, an OMV-based controllable two-way adaptor is reported, in which a CD47 nanobody (CD47nb) is fused onto OMV surface (OMV-CD47nb), with the outer surface coated with a polyethylene glycol (PEG) layer containing diselenide bonds (PEG/Se) to form PEG/Se@OMV-CD47nb. The PEG/Se layer modification not only mitigates the immunogenicity of OMV-CD47nb, thereby remarkedly increasing the dose that can be administered safely through intravenous injection, but also equips the formulation with radiation-triggered controlled release of OMV-CD47nb. Application of radiation to tumors in mice injected with the nanoformulation results in remodeling of TME. As two-way adaptors, OMV-CD47nb activates TAM phagocytosis of tumor cells via multiple pathways, including induction of M1 polarization and blockade of "don't eat me" signal. Moreover, this activation of TAMs results in the stimulation of T cell-mediated antitumor immunity through effective antigen presentation.

Clinical evaluation of anterior screw fixation for elderly patients with type II odontoid fractures.

STUDY DESIGN: A retrospective study of elderly patients who underwent anterior screw fixation for type II odontoid fractures between 2000 and 2009 was conducted. OBJECTIVE: To evaluate the clinical outcome of anterior screw fixation for type II odontoid fractures in elderly people and to provide valuable information for spinal surgeon reference. SUMMARY OF BACKGROUND DATA: Odontoid fractures are the most common fractures of the cervical spine in patients above 70 years of age, and patients above 80 years of age form the majority of spinal fractures. However, the optimum treatment of type II odontoid fractures in the geriatric population remains controversial. METHODS: A retrospective analysis was performed in 43 patients (19 women; mean age, 80.6 y; range, 65 to 92 y) with type II odontoid fractures who were consecutively admitted to a single medical center between January 2000 and October 2009. Twenty-eight patients had posteriorly displaced odontoid fractures and the remaining 15 had anteriorly displaced odontoid fractures according to the radiographical presentation. Neurological symptoms were present in 4 patients including 3 Frankel D and 1 Frankel C and always occurred in patients with posteriorly displaced odontoid process. The medical records, plain x-rays, and computed tomographic scans of all patients were reviewed. After surgery, patients were discharged with rigid cervical immobilization and clinical follow-ups were between 18 and 24 months (average, 21.3 mo). RESULTS: The mean displacement of odontoid process revealed by preoperative radiologic evaluation was 4.9 mm (ranged from 1 to 10 mm). Anterior screw fixation was performed successfully in 42 cases except 1 in which posterior C1-C2 fusion had to be undertaken to replace the original operation scheme because of technical difficulty. According to postoperative radiologic evaluation, 36 of 42 type II odontoid fracture cases treated with anterior screw fixation achieved fusion within 6 months. The fusion rate was 85.7% (36 of 42). Thirty-four patients regained normal cervical movement, 5 patients had about 25%, and 3 had >25% limited cervical motion. Sixteen patients achieved clinically excellent outcomes, 24 good, and 2 fair outcomes. CONCLUSIONS: Anterior screw fixation can be performed safely in elderly patients with type II odontoid fracture, and the clinical outcomes of this procedure were satisfactory. High fusion rates, low postoperative complications, and maintenance of cervical motion were acquired. The anterior screw fixation can be a reliable and reasonable treatment for type II odontoid fractures in the elderly patients.

Nanopores in two-dimensional materials: accurate fabrication.

Two-dimensional (2D) materials such as graphene and molybdenum disulfide have been demonstrated with a wide range of applications in electronic devices, chemical catalysis, single-molecule detection, and energy conversion. In the 2D materials, nanopores can be created, and the 2D nanoporous membranes possess many unique properties such as ultrathin thickness, high surface area, and excellent particle sieving capability, showing extraordinary promise in plenty of applications, such as sea water desalination, gas separation, and DNA sequencing. The performances of these membranes are mainly determined by the nanopore size, structure, and density, which, in turn, rely on the fabrication techniques of the nanopores. This review covers the important progress of nanopore fabrication in 2D materials and comprehensively compares these methods for the features of the introduced nanopores and their formation processes. Future perspectives are discussed on the opportunities and challenges in fabricating high-grade 2D nanopores.

[Clinical study of calcium phosphate cement loaded with recombinant human bone morphogenetic protein 2 combined with calcium phosphate cement loaded with antibiotic for chronic osteomyelitis with bone defect].

OBJECTIVE: To compare the effectiveness of calcium phosphate cement (CPC) loaded with recombinant human bone morphogenetic protein 2 (rhBMP-2) combined with CPC loaded with antibiotic versus CPC loaded with antibiotic alone in one stage for chronic osteomyelitis with bone defect. METHODS: A single-blind prospective randomized controlled clinical trial was conducted. Between April 2018 and April 2019, 80 patients of chronic osteomyelitis with bone defect in accordance with the random number table were randomly divided into two groups, 40 in the trial group (CPC loaded with rhBMP-2 combined with CPC loaded with antibiotic) and 40 in the control group (CPC loaded with antibiotic). There was no significant difference in gender, age, disease duration, lesion, and preoperative white blood cells (WBC) count, platelet count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) between the two groups ( P>0.05). All patients were implanted the corresponding CPC and external fixator after lesion clearance in the two groups. The postoperative WBC count, platelet count, ESR, CRP, hospital stay, cure rate of osteomyelitis, repaired bone defect volume, the time of external fixator removal, and the time of full weight-bearing of the affected limb were compared between the two groups. RESULTS: All patients were followed up 12-24 months, with an average of 18.4 months. There was no significant difference in WBC count, platelet count, ESR, and CRP between the two groups at 4 weeks after operation ( P>0.05). There were significant differences in WBC count, platelet count, and CRP in the two groups between 1 week before operation and 4 weeks after operation ( P<0.05). And the ESR showed no significant difference between pre- and post-operation in the two groups ( P>0.05). In the trial group, the anaphylactic exudate occurred in 1 patient with tibial osteomyelitis and the incision healed after oral administration of loratadine. The incisions of other patients healed by first intention in the two groups. One case of distal tibial osteomyelitis recurred in each group, and 1 case of humeral osteomyelitis recurred in the control group. The cure rates of osteomyelitis were 97.5% (39/40) in the trial group and 95% (38/40) in the control group, showing no significant difference between the two groups ( χ 2 =0.000, P=1.000). There was no significant difference in the repaired bone defect volume and hospital stay between the two groups ( P>0.05). X-ray film and CT showed that the bone defects were repaired in the two groups. The time of external fixator removal and the time of full weight-bearing of the affected limb were significantly shorter in the trial group than in the control group ( P<0.05). CONCLUSION: Application of CPC loaded with rhBMP-2 and antibiotic in one stage is effective for the chronic osteomyelitis with bone defect, which can accelerate the bone regeneration in situ to repair bone defect, reduce the trauma, shorten the course of treatment, and obtain good function of the affected limb.

Downregulation of miR-155-5p facilitates enterovirus 71 replication through suppression of type I IFN response by targeting FOXO3/IRF7 pathway.

Enterovirus 71 (EV71), the major cause of hand-foot-and-mouth disease (HFMD), has evolved diverse strategies to counter the type I interferon (IFN-I) response during infection. Recently, microRNAs have regulatory roles in host innate immune responses to viral infections; however, whether EV71 escapes the IFN-I antiviral response through regulation of miRNAs remains unclear. Using a microarray assay, microRNA-155-5p (miR-155-5p) was found to be significantly up-regulated in serum from patients with EV71 infection and the increased expression of miR-155-5p was further confirmed in vivo and in vitro in response to EV71 infection. miR-155-5p overexpression suppressed EV71 titers and VP1 protein level, while miR-155-5p inhibition had an opposite result. Moreover, we found that miR-155-5p overexpression enhanced EV71 triggered IFN I production and the expressions of IFN-stimulated genes (ISGs), while inhibition of miR-155-5p suppressed these processes. Furthermore, bioinformatics analysis and luciferase reporter assay demonstrated that miR-155-5p directly targeted forkhead box protein O3 (FOXO3) and negatively regulated FOXO3/IRF7 axis, an important regulatory pathway for type I IFN production during EV71 infection. Inhibition of FOXO3 reversed the effects of miR-155-5p inhibitor on EV71 replication and the type I IFN production. Importantly, in EV71 infection mice, agomir-155-5p injection resulted in a significant reduction of viral VP1 protein expressions in brain and lung tissues, increased IFN-α/ß production and increased mice survival rate. In contrast, antagomir-155-5p enhanced EV71 induced these effects. Collectively, our study indicates that weaken miR-155-5p facilitates EV71 replication through suppression of type I IFN response by FOXO3/IRF7 pathway, thereby suggesting a novel strategy for developing effective antiviral therapy.

Accelerated Rhodamine B removal by enlarged anode electric biological (EAEB) with electro-biological particle electrode (EPE) made from steel converter slag (SCS).

Electro-biological particle electrode (EPE) made from steel converter slag (SCS) was used as a particle electrode in an enlarged anode electric biological (EAEB) reactor for Rhodamine B (RhB) wastewater treatment, and its purification performance and microbial community were examined. The results revealed that (1) the EAEB reactor showed much higher average removal rates of RhB, COD and NH4+-N, i.e. 91.68%, 87.63%, and 90.54%, which meant an increase by 59.86%, 20.48%, and 14.22%, respectively, compared with BAF; (2) The optimum current intensity (CI) for simultaneously removing RhB, COD and NH4+-N in the EAEB reactor was at 1.00 A; and (3)Methylophilus, Aeromonas, Pseudomonas, Pelomonas and Zoogloea accounted for the main bacterial community in EAEB. Therefore, the EAEB reactor with EPE produced from steel converter slag (SCS) was suitable to simultaneously remove RhB, COD and NH4+-N.

Thermophysical properties of lignocellulose: a cell-scale study down to 41 K.

Thermal energy transport is of great importance in lignocellulose pyrolysis for biofuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells) is prepared to characterize their thermal properties from room temperature down to ∼ 40 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly depends on the heat capacity's change.

Electron transport and bulk-like behavior of Wiedemann-Franz law for sub-7 nm-thin iridium films on silkworm silk.

For ultrathin metallic films, either supported or free-standing, the inside nanocrystalline nature significantly reduces the electron and thermal transport. Quantum mechanical reflection of electrons at the grain boundary reduces the electrical conductivity further than the thermal conductivity, leading to a Lorenz number in the order of 7.0 × 10(-8) W Ω K(-2), much higher than that of the bulk counterpart. We report on a finding that for ultrathin (0.6-6.3 nm) iridium films coated on degummed silkworm silk fibroin, the electron transport is around 100-200% higher than that of the same film on glass fiber, even though the grain size of Ir film on silkworm silk is smaller than that on glass fiber. At the same time, the thermal conductivity of the Ir film is smaller or close to that of the film on glass fiber. Its Lorenz number is found close to that of bulk crystalline Ir despite the nanocrystalline structure in the Ir films. This is similar to the behavior of metallic glasses. Our study of gold films on silkworm silk reveals the same trend of change as compared to that on glass fiber. Electron hopping and tunneling in silkworm silk is speculated to be responsible for the observed electron transport. The finding points out that silk could provide a better substrate for flexible electronics with significantly faster electron transport.

Artificial disk replacement in the treatment of degenerative cervical disk disorder: a 30-year follow-up study.

STUDY DESIGN: Retrospective case series study. OBJECTIVE: To clarify the results of a long-term (30 yr) follow-up study of artificial disk replacement (ADR) for the treatment of cervical disk disease. SUMMARY OF BACKGROUND DATA: The use of the ADR procedure has become widespread during the past 10 years. Its purpose is to preserve motion of the functional spinal unit. However, the long-term results are unknown. METHODS: Thirty-seven patients underwent ADR between 1980 and 1985 in the Department of Orthopedic Surgery, Changzheng Hospital. Twenty-one patients, who had a complete follow-up, underwent radiographical evaluation to detect heterotopic ossification, segmental range of motion, and adjacent segmental changes. In addition, patients were asked to complete preoperative and postoperative visual analogue scale, neck disability index, and 36-Item Short Form Health Survey questionnaires for evaluation of neurological function and pain severity. The occurrence of adverse events and reoperations was examined and these parameters served as indicators of device safety. RESULTS: Twenty-one patients had a complete follow-up average of 30 years (range, 28-33 yr). The 21 patients reported improvement of the preoperative neurological symptoms. At the last follow-up, the motion was preserved in 19 of the 26 (73%) segments. None of the patients presented with symptomatic adjacent segment degeneration. Nineteen of the 21 (90%) patients presented heterotopic ossification, but none of them underwent reoperation correlated with heterotopic ossification. No device-related adverse events were recorded. CONCLUSIONS: Artificial disk replacement to treat degenerative cervical disk disorders can preserve the motion of the spinal unit in young patients, which fulfills the original purpose of its design. We consider this procedure is worth applying in such a population. However, whether this procedure can prevent adjacent segment degeneration will require further investigation. LEVEL OF EVIDENCE: 2.

Application of the cervical subaxial anterior approach at C2 in select patients.

The purpose of this study was to assess the feasibility and radiographic indications of using the subaxial anterior approach for decompression and fusion at C2. Anterior exposure at C2 was difficult and associated with increased morbidity. The subaxial anterior approach is easy and familiar to spine surgeons but did not provide satisfying exposure in all patients. This article describes a series of patients undergoing anterior surgery involving C2 through the subaxial anterior approach. Patients were selected based on lateral extension radiographs showing a mandibular angle higher than the C3 upper endplate. Forty-two patients (29 men and 13 women) with average age of 45 years and an average follow-up of 9.7 months were reviewed. Etiologies included Hangman's fracture (n=35), traumatic disk herniation at C2-C3 (n=1), C3 fracture (n=2), ossification of the posterior longitudinal ligament (n=2), and tumor (n=2). Single-level diskectomy (n=36) and corpectomy (n=6) were performed. Exposure was satisfactory, and operations went smoothly in all patients except in 1 man with a muscular neck. One (2.4%) postoperative complication of choking and trouble swallowing liquids was observed and diminished in 3 months with no treatment. Pre- and postoperative Japanese Orthopaedic Association scores were 13.86 ± 2.25 and 16.50 ± 0.76, respectively, with an improvement rate of 85% ± 24% in 14 patients who had preoperative neurological dysfunction. A fusion rate of 100% was achieved. The subaxial anterior approach may be simple and safe for exposure at C2 in select patients. Complicated exposure, such as the transoral or retropharyngeal approach, should be avoided in these patients.