Clinical and virological characteristics of chronic hepatitis B with concurrent hepatitis B E antigen and antibody detection

The concurrent detection of hepatitis B e antigen (HBeAg) and its corresponding antibody (anti-HBe) in patients with chronic hepatitis B virus (HBV) infection is well established but the clinical features remain poorly understood. Demographic information, clinical and laboratory data were collected from 1624 consecutive inpatient records of patients with chronic hepatitis B. Viral genotype, basic core promoter and precore mutations were determined by direct sequencing. In vitro HBeAg and anti-HBe binding experiments were conducted with three pairs of HBeAg-positive and anti-HBe-positive serum samples, which were mixed at variable ratios and incubated at 37°C for 3-24h. Of the 1624 chronic patients, 169 (10.4%) had concurrent HBeAg and anti-HBe positivity, and this was associated with intermediate age and HBV-DNA load, higher alanine aminotransferase level and more pronounced liver damage compared with HBeAg-positive or anti-HBe-positive patients alone. HBeAg and anti-HBe titres (median and interquartile range, S/CO) in the concurrent positive group were 4.2 (1.8-9.6) and 0.54 (0.27-0.72), which were closer to their respective cut-off values than those of HBeAg-positive or anti-HBe-positive groups alone. For the cases successfully sequenced, 110/134 (82.1%) harboured T1762/A1764 or/and A1896 mutants. The binding experiments showed that HBeAg and anti-HBe could be concurrently observed provided an optimal ratio (HBeAg to anti-HBe) was chosen. In antiviral treatment-naive patients, concurrence of HBeAg and anti-HBe was not uncommon, and such patients had profound liver disease. An optimal ratio between HBeAg and anti-HBe led to their concurrent detection when sera were tested by sensitive assays.

[Clinical study on viral hepatitis combined with aplastic anemia]

OBJECTIVE

To study the clinical features, outcomes and treatments of viral hepatitis combined with aplastic anemia.

METHODS

25 cases diagnosed as viral hepatits combined with aplastic anemia in Beijing Ditan Hsopital between April 2004 and September 2009 were retrospectively analyzed. In this group of patients aplastic anemia was finally diagnosed by bone marrow aspiration. We collected clinical data of these patients, including a history of liver disease, drug allergies, hospital medication history, laboratory data, and then performed descriptive analysis.

RESULTS

25 patients with viral hepatitis were diagnosed as complicated with aplastic anemia by histopathological data. Among these patients, 17 were male and 8 were women. Viral hepatitis included: chronic hepatitis B (12 cases), chronic hepatitis C (4 cases), acute hepatits E (1 case), hepatitis caused by CMV infection (1 case), and unclassified hepatitis (7 cases). Among these patients, 7 were diagnosed as severe hepatits. Considering previous history, only 3 patients had history of short term interferon therapy before hospitalization, and the remaining patients did not use drug that affects blood system. Treatments were as followings: using colony stimulating factor in 6 patients, gamma globulin in 9 patients, glucocorticoids in 3 patients, erythropoietin in 1 patient, only oral drug to raise erythrocytes in 2 patients, red blood cells transfusion in 6 patients, platelets transfusion in 2 patients. As for clinical outcomes, 20 patients acquired improved condition and were dicharged, 3 patients were discharged voluntarily and 2 patients died of severe hepatits combined with other complications.

CONCLUSION

Main treatments of viral hepatitis combined with aplastic anemia were to treat primary hepatopathy and nucleoside analogue-based antiviral therapy, to provide symptomatic and supportive treatment for blood diseases. Blood diseases would recover simultaneously while liver disease was improved, and the prognosis was good.

Room-temperature nonequilibrium growth of controllable ZnO nanorod arrays

In this study, controllable ZnO nanorod arrays were successfully synthesized on Si substrate at room temperature (approx. 25°C). The formation of controllable ZnO nanorod arrays has been investigated using growth media with different concentrations and molar ratios of Zn(NO3)2 to NaOH. Under such a nonequilibrium growth condition, the density and dimension of ZnO nanorod arrays were successfully adjusted through controlling the supersaturation degree, i.e., volume of growth medium. It was found that the wettability and electrowetting behaviors of ZnO nanorod arrays could be tuned through variations of nanorods density and length. Moreover, its field emission property was also optimized by changing the nanorods density and dimension.

The preventive effects of pulsed electromagnetic fields on diabetic bone loss in streptozotocin-treated rats

The present study was the first report demonstrating that pulsed electromagnetic field (PEMF) could partially prevent bone strength and architecture deterioration and improve the impaired bone formation in streptozotocin-induced diabetic rats. The findings indicated that PEMF might become a potential additive method for inhibiting diabetic osteopenia or osteoporosis.

INTRODUCTION

Diabetes mellitus (DM) can cause various musculoskeletal abnormalities. Optimal therapeutic methods for diabetic bone complication are still lacking. It is essential to develop more effective and safe therapeutic methods for diabetic bone disorders. Pulsed electromagnetic field (PEMF) as an alternative noninvasive method has proven to be effective for treating fracture healing and osteoporosis in non-diabetic conditions. However, the issue about the therapeutic effects of PEMF on diabetic bone complication has not been previously investigated.

METHODS

We herein systematically evaluated the preventive effects of PEMF on diabetic bone loss in streptozotocin-treated rats. Two similar experiments were conducted. In each experiment, 16 diabetic and eight non-diabetic rats were equally assigned to the control, DM, and DM + PEMF group. DM + PEMF group was subjected to daily 8-h PEMF exposure for 8 weeks.

RESULTS

In experiment 1, three-point bending test suggested that PEMF improved the biomechanical quality of diabetic bone tissues, evidenced by increased maximum load, stiffness, and energy absorption. Microcomputed tomography analysis demonstrated that DM-induced bone architecture deterioration was partially reversed by PEMF, evidenced by increased Tb.N, Tb.Th, BV/TV, and Conn.D and reduced Tb.Sp and SMI. Serum OC analysis indicated that PEMF partially prevented DM-induced decrease in bone formation. In experiment 2, no significant difference in the bone resorption marker TRACP5b was observed. These biochemical findings were further supported by the dynamic bone histomorphometric parameters BFR/BS and Oc.N/BS.

CONCLUSIONS

The results demonstrated that PEMF could partially prevent DM-induced bone strength and architecture deterioration and improve the impaired bone formation. PEMF might become a potential additive method for inhibiting diabetic osteoporosis.

One germline mutation of PTCH gene in a Chinese family with non-syndromic keratocystic odontogenic tumours

Keratocystic odontogenic tumours (KOCTs) are common benign cystic tumours that arise sporadically or associated with nevoid basal cell carcinoma syndrome (NBCCS). PTCH mutation can be found in sporadically or NBCCS associated KOCTs. Few PTCH mutations in families with non-syndromic KOCTs have been reported. Through PCR and gene sequence analysis, the authors discovered one missense mutation c.3277G>C in exon 19 of PTCH gene in a Chinese family with non-syndromic KOCTs. This mutation causes one highly conserved glycine residue transit to arginine on the 10th transmembrane region of PTCH protein. This work revealed that the missense mutation of PTCH is the causative and dominant gene of KOCTs in this family.

A Multi-Anvil High Pressure System with Synchrotron X-Ray Probe: New Opportunities for In-Situ Materials Research at Simultaneously High Pressure and Temperature

We describe the multi-anvil, large-volume, high-pressure facility that is being constructed at the GeoSoilEnviroCARS (Sector 13) at the Advanced Photon Source, Argonne National Laboratory. Various multi-anvil, high-pressure apparatus will be used to cover pressure and temperature conditions up to 40 GPa and 3000 °C, respectively, with milimeter to centimeter sized samples. This national facility is open to all users, providing excellent opportunities for high pressure, high temperature experiments.

Lithium delivery enhances bone growth during midpalatal expansion

Lithium is an activator of β-catenin signaling, and β-catenin mediates bone acquisition in response to mechanical loading in the bone. We tested the hypothesis that lithium enhances new bone formation during midpalatal suture expansion. Forty-eight Wistar rats with or without suture expansion were gavage-fed daily with lithium chloride or sodium chloride. We labeled the rats with bromodeoxyuridine to evaluate the proliferation and differentiation of the osteoprogenitors. Lithium increased β-catenin expression and cell proliferation in expanding sutures. Initial delay in the differentiation of osteoprogenitors into mature osteoblasts by lithium treatment corresponded with expansion of pre-osteoblasts, which preceded the increase of new bone formation in the suture. These results suggested that β-catenin regulates proliferation of osteoprogenitors and maturation of osteoblasts during midpalatal suture expansion osteogenesis, and that lithium enhances bone regeneration by elevating β-catenin expression. Lithium treatment could be a pharmaceutical aid to improve the stability of orthodontic treatment like rapid palatal expansion.

PbTiO3 nanofibers with edge-shared TiO6 octahedra

A new tetragonal phase of PbTiO(3) was discovered, in which each TiO(6) octahedron pair shares an edge and stacks over following pairs in an interlaced manner to form a one-dimensional (1D) columned structure along the c-axis. This new tetragonal phase of PbTiO(3) transforms into a normal perovskite phase in air at elevated temperature.

Size- and density-controlled synthesis of TiO2 nanodots on a substrate by phase-separation-induced self-assembly

This work presents a facile way, i.e. phase-separation-induced self-assembly, to prepare TiO(2) nanodots on a substrate. This method induces convective flow in a spin-coated titanium tetrabutoxide (TBOT)/polyvinyl pyrrolidone (PVP)/ethanol liquid film through the Marangoni effect and turns TBOT into crystalline TiO(2) nanodots on a substrate after calcination. The size and density of the TiO(2) nanodots can be finely tailored by controlling the concentrations of TBOT and PVP in the precursor sol. The TiO(2) nanodot-deposited surface showed a hydrophilic characteristic and the wettability was obviously improved by increasing nanodot size.

Enhanced Luminescence of Eu-Doped TiO2Nanodots

Monodisperse and spherical Eu-doped TiO2nanodots were prepared on substrate by phase-separation-induced self-assembly. The average diameters of the nanodots can be 50 and 70 nm by changing the preparation condition. The calcined nanodots consist of an amorphous TiO2matrix with Eu3+ions highly dispersed in it. The Eu-doped TiO2nanodots exhibit intense luminescence due to effective energy transfer from amorphous TiO2matrix to Eu3+ions. The luminescence intensity is about 12.5 times of that of Eu-doped TiO2film and the luminescence lifetime can be as long as 960 μs.

Possible involvement of brain tumour stem cells in the emergence of a fast-growing malignant meningioma after surgical resection and radiotherapy of high-grade astrocytoma: case report and preliminary laboratory investigation

The case of a 62-year old man diagnosed with radiation-induced meningioma (RIM) after treatment for astrocytoma with an unusually short latency period of 7 months is reported. The patient first presented with a 2-month history of memory decline. Magnetic resonance imaging (MRI) showed a tumour in the left parieto-temporal lobe. Gross total resection was performed and the tumour was confirmed to be an astrocytoma. The patient received cranial radiotherapy 2 weeks later, however 7 months after radiation treatment the patient presented with headache and vomiting. MRI showed massive meningeal enhancement in the left frontal lobe, which progressively enlarged. The patient's clinical condition deteriorated and a second craniotomy was performed with complete removal of the secondary tumour, which was shown to be a malignant meningioma. Immunohistochemical staining identified CD133-positive cells in both tumours. A rare fraction of brain tumour stem cells (BTSC) was isolated from the primary astrocytoma using a serum-free culture system, suggesting that BTSC may have been involved in the rapid emergence of RIM after resection and radiation of the primary astrocytoma.

Electrolytic deposition of octacalcium phosphate/collagen composite coating on titanium alloy

Osteointegration of titanium or its alloy with bone can be greatly improved by calcium phosphate coatings, and further enhanced by an extracellular matrix protein layer such as collagen. In this study, an octacalcium phosphate (OCP)/collagen composite coating layer on Ti6Al4V substrate was prepared using electrolytic deposition method. A layer of OCP mineral consisting of flake-like crystals was first formed on the Ti6Al4V substrate. Subsequently, mineralized collagen fibrils were deposited on the former OCP layer. These collagen fibrils were interconnected and well adhered on the OCP layer so that they were immobilized. The microstructure of the composite coating varied with collagen concentration in the electrolyte. This study could offer a possibility of fabricating a desired surface matrix on orthopedic implants to enhance bone formation and fixation of implants.

Effect of PEG amount in amorphous calcium phosphate on its crystallized products

Biphasic alpha-tricalcium phosphate/beta-tricalcium phosphate (alpha/beta-TCP) with a designed phase ratio is thought to have controllable dissolution-reprecipitation behavior that is significant in the repair and regeneration of bone. Amorphous calcium phosphate (ACP) was selected as a precursor to prepare biphasic alpha/beta-TCP. The influence of polyethylene glycol (PEG) content in ACP on its crystallization, or on the phase ratio of the resulting biphasic TCP, was investigated. ACP was synthesized by the reaction of Ca(NO(3))(2) with (NH(4))(2)HPO(4) using PEG as an additive. Depending on the amount of PEG addition, resulting ACP could be crystallized to alpha-TCP, beta-TCP or biphasic alpha/beta-TCP after heat-treatment at 800 degrees C, showing that PEG addition is a critical factor to tailor the phase ratio of biphasic alpha/beta-TCP. One reason for the influence of PEG is that ACP with different PEG content could have two types of unit structures that tend to form alpha-TCP and beta-TCP after crystallization.

Brain tumour stem cells and neural stem cells: still explored by the same approach?

Brain tumour stem cells (BTSCs) are chiefly responsible for the in vivo long-term growth and recurrence of malignant gliomas and may be a potential treatment target. They resemble neural stem cells (NSCs), so their self-renewal and differentiation are currently investigated by the same methods used to study NSCs. There are, however, essential differences between these cell types: in many cases the marker expression pattern of BTSCs does not match the CD133(+)/NSE(-)/FAP(-) pattern of NSCs; BTSC tumourigenicity is independent of marker expression; and while attachment, serum-containing medium and withdrawal of mitogens (epidermal growth factor [EGF] and basic fibroblast growth factor [bFGF]) are essential to induce NSCs to differentiate, they do not affect BTSC tumourigenicity. Evidence implies that research on the renewal and differentiation of BTSCs should be orientated towards tumourigenicity and is essentially a pharmaceutical problem. Such an approach may contribute to the development of an accurate definition of BTSCs and to the search for selective differentiation-inducing drugs for BTSCs.

Position and density control in hydrothermal growth of ZnO nanorod arrays through pre-formed micro/nanodots

Position- and density-controlled ZnO nanorod arrays (ZNAs) were successfully grown on a Si substrate through a low temperature (90 °C) hydrothermal approach assisted by pre-formed ZnO micro/nanodots. The ZnO dots on Si substrates were prepared by a spin-coating technique, through which the pattern and density of the dots could be easily changed. Accordingly, the position- and density-controlled growth of ZNAs was achieved. For the resulting density-controlled ZNAs, the density could range from (5.6 ± 0.01) × 10(2) to (1.2 ± 0.01) × 10(2) rods µm(-2). The room-temperature photoluminescence (PL) spectrum of ZNAs exhibited excellent UV emission. The water wettability measurements of the ZNAs with different density showed good hydrophobicity, and the ZNAs with the lowest density revealed a superhydrophobic characteristic with a water contact angle of 166.1°.

Room-temperature preparation of ZnO nanosheets grown on Si substrates by a seed-layer assisted solution route

A facile route to prepare two-dimensional ZnO nanosheet structures on Si substrates was developed through the adoption of a ZnO seed-layer and suitable growth medium in this work. The characterization results showed that ZnO nanosheets could be grown on Si substrates with a pre-formed ZnO seed-layer at room temperature. The ZnO nanosheets, with thickness of 20-25 nm, were interwoven into networks to form a continuous nanosheet film. Room-temperature measurements of the photoluminescence (PL) spectra and water wettability for the resulting ZnO nanosheet structures showed high intensity ratio of the UV emission to the defect emissions and good hydrophilic property without UV illumination. The present work demonstrates that the adoption of a ZnO seed-layer is an effective approach for room-temperature growth of ZnO nanosheets grown on substrates.

Effects of pulsed electromagnetic field vibration on tooth movement induced by magnetic and mechanical forces: a preliminary study

BACKGROUND

This study was designed to determine whether or not high-frequency and low-magnitude vibration affects orthodontic tooth movement caused by magnetic or/and mechanical forces.

METHODS

Forty-four 7-week-old Wistar rats were randomly divided into four groups, with each group further divided into experimental and control subgroups. Neodymium-Iron-Boron (Nd-Fe-B) magnets and Sentalloy closed coil springs were placed between maxillary or mandibular first molars and incisors to activate tooth movement. The animals of experimental subgroups were exposed to the vibration induced by pulsed electromagnetic fields (PEMF) whilst the control subgroups were under normal atmosphere. The experiment lasted for 14 days and all of the animals were sacrificed for examination. The changes in the space between the molar and incisor were measured to indicate the amount of tooth movement.

RESULTS

The coil springs, either with sham or active magnets, move molar much more than magnets alone, regardless of absence or presence of PEMF (p < 0.001). Under PEMF, the coil spring moved significantly more amount of tooth movement than that of coil-magnet combination (p < 0.01), as did the magnets compared to sham magnets (p < 0.019). Under a non-PEMF scenario, there was no significant difference in tooth movement between coil spring and coil-magnets combination, nor was there difference between magnets and sham magnets.

CONCLUSIONS

It is suggested that the PEMF-induced vibration may enhance the effect of mechanical and magnetic forces on tooth movement.

Preparation of nanosized beta-tricalcium phosphate particles with Zn substitution

Nanosized beta-ZnTCP powders with different Zn contents were prepared through coprecipitation of ACP out of the CaCl2-ZnCl2-Na3PO4-PEG system, and calcination of the ACP precursor at 800 degrees C for 3 h. The characterizations of the products showed that the products belong to beta-TCP phase, and the particles sizes of them are about 300 nm, smaller than that of beta-TCP (500 nm). Both the Zn2p binding energy and lattice parameter variations of beta-TCP evidenced that Zn had substituted for Ca in the lattice. Such nanosized beta-ZnTCP powders could be used as bone repair materials with desired and sustained release of Zn.

Fabrication and evaluation of Zn containing fluoridated hydroxyapatite layer with Zn release ability

A biphasic layer with a Zn-containing beta-tricalcium phosphate (ZnTCP) phase and a fluoridated hydroxyapatite (FHA) phase on titanium alloy substrate was prepared by the sol-gel technique. Scanning electron microscopy and energy-dispersive X-ray analysis results showed the ZnTCP/FHA layer to have a heterogeneous surface with microscaled gibbous structures originating from ZnTCP particle agglomeration. This layer had a slow and sustained Zn release behavior. The scratch test result of the ZnTCP/FHA layer was 489+/-4mN, indicating good interface bonding between the layer and substrate. The ZnTCP/FHA layer supported cell growth, and showed a statistically significant increase in cell viability in comparison with another biphasic layer (TCP/FHA) without Zn. This work demonstrates that the present biphasic ZnTCP/FHA layer has the potential to play a significant role in enhancing bone growth when used as the outermost part of bioactive coatings on metallic implants.

In vitro bioactivity and osteoblast-like cell test of zinc containing fluoridated hydroxyapatite films

Zinc containing fluoridated hydroxyapatite (ZnFHA) films on Ti6Al4V substrates was prepared using sol-gel dip-coating method. The release of zinc ions from ZnFHA film was controlled mainly by the zinc content in the film. The release behavior showed an initial rapid increase release followed by a tapering-off and directed to a constant value at longer time. After soaking in SBF for 8 days, a layer was deposited and completely covered the original surface of the ZnFHA film, indicating good in vitro "bioactivity." The osteoblast-like MG63 cells were seeded on the ZnFHA films; FHA film and Ti6Al4V substrate were used as control. The cell culture result showed that cell adhesion and proliferation on ZnFHA films were significantly increased compared with the controls. The results in this work suggest that ZnFHA films on Ti6Al4V substrates can function as an implant with good bioactivity and cytocompatibility.

Pb speciation versus TCLP release in army firing range soils

A series of soil parameter and mineralogical investigative techniques were applied to assess the Pb speciation in four US Army firing range soils that presented significantly different Pb leaching regimes and soil characteristics. Soil gradation tests were complemented by total chemical analyses, X-ray powder diffraction (XRPD), Rietveld quantification, optical microscopy and scanning electron microscopy (SEM) analyses. The bulk geotechnical, mineralogical and chemical analyses pointed to two possible Pb retention mechanisms: precipitation as lead carbonate and sorption in the case of fine-grained soils. Lead speciation and mobility was further investigated by the toxicity characteristic leaching procedure (TCLP) and sequential extraction test (SET). As the TCLP Pb concentrations did not necessarily reflect the total Pb analysis of the soils, the Pb leachability ratio (TCLP/total) was found to be controlled by soil mineralogy and its response to changes in system pH. Geochemical modeling, using Visual MINTEQ, was employed to evaluate the mechanisms that controlled the observed TCLP Pb leaching behavior. It was found that lead carbonate precipitation/dissolution reactions controlled Pb TCLP leachability in all soils, while sorptive phenomena did not seem to play a role even in the case of fine-grained soils. More specifically, TCLP Pb leachability was controlled by the pH, the available Pb and the available carbonate in solution. This indicates that geochemical modeling strongly complimented TCLP Pb analyses. Thus, geochemical modeling is an important assessment tool to evaluate the magnitude of site-specific Pb-related environmental problems in firing range soils. Carbonation reactions, involving metallic Pb, that occur during the SET obscure its ability to reliably ascertain Pb speciation. More specifically, SET lumps the extractable Pb into predetermined phase categories that may not be truly representative of the actual soil mineralogy or dominant forms of Pb in the soil. A thorough geotechnical, mineralogical and chemical investigation of firing range soils, complemented by geochemical modeling, was therefore found to be a more reliable approach to evaluate Pb speciation and TCLP release in firing range soils.

Double-sided laser heating system at HPCAT for in situ x-ray diffraction at high pressures and high temperatures

An overview of a YLF:Nd laser heating system at the undulator x-ray diffraction station (16ID-B) of the high-pressure collaborative access team (HPCAT) of the Advanced Photon Source is presented. Based on the double-sided laser heating technique, the system is designed with considerable effort on the mechanical and optical stabilities, features for user-friendly operation, and the capability of accommodating diamond anvil cells of various heights up to 68 mm. This system has been used for x-ray diffraction studies of a wide range of materials to over 150 GPa and above 3000 K. Applying the laser heating technique to radial x-ray diffraction studies at simultaneous high-pressure and high-temperature (PT) conditions requires heating to be conducted at variable angles relative to the x-ray direction. A rotation laser heating design is discussed.

Changes in the physical properties of human premolar cementum after application of 4 weeks of controlled orthodontic forces

This study was performed to assess the relationship between the magnitude of orthodontic force and physical properties of individual human cementum, and to identify the sites that may be predisposed to root resorption. The findings may assist in relating physical properties of dental root cementum and its susceptibility to root resorption. Sixteen maxillary first premolar teeth were selected in eight orthodontic patients (three males and five females), mean age 14.8 years (range 11.2-17.5 years), requiring first premolar extractions. In each patient, a light orthodontic force of 25 cN was applied buccally using a sectional archwire on the first premolar on one side, while a heavy force of 225 cN was applied to the contralateral side. The teeth were extracted 4 weeks after initial force application. Hardness and elastic modulus were measured on the buccal and the lingual surfaces of the cementum at the cervical, middle, and apical third of the root. The results showed that the mean hardness and elastic modulus of cementum in the light force group were greater than in the heavy force group at all positions. There were highly significant differences in both hardness and elastic modulus between the heavy and light force groups (P < 0.01). The mean hardness and elastic modulus of cementum gradually decreased from the cervical to the apical regions for buccal as well as lingual surfaces in both groups. There was, however, an insignificant difference between hardness and elastic modulus on the buccal surface compared with the lingual surface (P < 0.05). It was concluded that the hardness and elastic modulus of cementum were affected by the application of orthodontics forces.

Cephalometric evaluation of condylar and mandibular growth modification: a review

OBJECTIVE

Based on a wealth of orthodontic archives, this work aims to review the cephalometric analysis systems that can identify the changes in condylar and mandibular position as well as growth direction in response to bite jumping therapy.

DESIGN

Numerous cephalometric approaches were screened to testify their feasibility and reliability in accurately depicting the growth modification of the condyle and the mandible. The critical assessment of the working mechanisms of these cephalometric methods was elaborated to help build up the rationale and justification for their clinical use.

RESULTS

1) The changes in condylar and mandibular size, position and growth direction can be identified by using lateral cephalograms with closed-mouth or open-mouth posture. 2) With superimposition methods where the anatomical structures for superimposition registration must be stable and reproducible, the growth modification of the condyle and the mandible between two time-points is qualitatively demonstrated in a diagram if reference lines are not constructed. The growth modification can be quantitatively identified if the reference lines are created. 3) With non-superimposition methods, the size and position of the condyle and the mandible are separately identified for each time-pint by relating them to the stable reference structures. The growth modification between two time-pints is evaluated by comparing the two separate measurements.

CONCLUSION

The application of a standardized and well designed cephalometric evaluation system may reduce the bias that attribute to the arbitrariness of the clinical effects of bite jumping functional appliances.

Preparation, characterization and cytocompatibility of porous ACP/PLLA composites

The purpose of this work was to incorporate amorphous calcium phosphate (ACP) into porous poly(L-lactic acid) (PLLA), because ACP is capable of fast phase transformation and morphological change in body fluid, such, a desired pore wall surface within bone tissue engineering scaffolds can be created. A highly porous ACP/PLLA composite was prepared by a thermally induced phase separation technique. The results showed that the composite had an interconnected pore structure with 100 mum macropores and 10 mum micropores, and 91% porosity; 40 nm primary particles of ACP were agglomerated to 3 mum aggregates, and the aggregates were homogeneously distributed in pore walls; These aggregates showed to be in situ transformed into bone-like apatite after 1 h soaking in phosphate buffered saline solution. Human osteoblast-like cell culture showed that the ACP/PLLA composite had better cell adhesion and alkaline phosphotase activity than pure PLLA. This study demonstrates that the ACP/PLLA composite can enhance cytocompatibility and could act as a promising scaffold for bone tissue engineering.

Beating the miscibility barrier between iron group elements and magnesium by high-pressure alloying

Iron and magnesium are almost immiscible at ambient pressure. The low solubility of Mg in Fe is due to a very large size mismatch between the alloy components. However, the compressibility of Mg is much higher than that of Fe, and therefore the difference in atomic sizes between elements decreases dramatically with pressure. Based on the predictions of ab initio calculations, we demonstrate in a series of experiments in a multianvil apparatus and in electrically and laser-heated diamond anvil cells that high pressure promotes solubility of magnesium in iron. At the megabar pressure range, more than 10 at. % of Mg can dissolve in Fe and then the alloy can be quenched to ambient conditions. A generality of the concept of high-pressure alloying between immiscible elements is demonstrated by its application to two other Fe group elements, Co and Ni.