Efficient optical coupling in AlGaN/GaN quantum well infrared photodetector via quasi-one-dimensional gold grating

In this letter, a new kind of grating, quasi-one-dimensional gold grating, has been proposed to enhance the optical coupling in AlGaN/GaN quantum well infrared photodetector (QWIP). The electric field distribution, current density and energy flow are analyzed by an algorithm of finite element method (FEM). Significantly enhanced electric field component E(z) perpendicular to multiple quantum wells (MQWs) is explained by introducing the resonant coupling of surface plasmon polariton (SPP) and localized surface plasmon (LSP). The |E(z)|(2) in MQWs reaches 0.85 (V/m(2) when the electric field intensity (|E(0)|(2)) of normal incidence is 1 (V/m(2) at 4.65 μm, showing 2 times and 1.3 times increase compared with that obtained via a one-dimensional gold grating and a two-dimensional gold grating, respectively. The results confirm that the quasi-one-dimensional gold grating provides more plasma excitation source and higher charge density with structure optimization, resulting in a high optical coupling efficiency of 85% in quantum well region.

A strategy for removal of foreign body in mandible with navigation system

Navigation surgery in the mandible has rarely been reported because of the complexities of navigating a mobile structure. In this article, we present a simple and novel strategy for removal of a foreign body in the mandible using a navigation system. A female diagnosed with a foreign body in the left mandible underwent navigation surgery using a BrainLAB system. We used a special open splint fabricated with acrylic resin to successfully perform the mandibular navigation. This strategy may be appropriate for many types of mandibular navigation surgery.

The neuroprotective effects of β-hydroxybutyrate on Aβ-injected rat hippocampus in vivo and in Aβ-treated PC-12 cells in vitro

Alzheimer's disease is a neurodegenerative disorder associated with the deposition of the peptide amyloid-beta (Aβ) in senile plaques and cerebral vasculature. The neurotoxic mechanisms of this condition have been linked to oxidative-stress-induced apoptosis leading to widespread neuronal loss. Herein, we demonstrate the neuroprotective effects of a ketone body D-β-hydroxybutyrate (β-HB) in neural cell lines and an animal model induced by injecting Aβ into the hippocampus. Using histological examination and the TUNEL assay, we show that administration of exogenous β-HB effectively prevents Aβ deposition and neuron apoptosis in this rat model. β-HB pretreatment also relieves the oxidative stress in Aβ-induced PC-12 cells, as shown by decreased intracellular reactive oxygen species and Ca(2+) levels, activated Nrf2 and recovered superoxide dismutase and catalase activities. Consequently, the apoptotic pathway is also inhibited in these cells, with decreased levels of p53, caspase-12, caspase-9, caspase-3; a decreased Bax/Bcl-2 ratio; and decreased cytochrome c release. Taken together, our study provides a molecular basis for the neuroprotective effects of β-HB in line with the suppression of oxidative stress and the inhibition of apoptotic protein activation.

Hypertension and risk of depression in the elderly: a meta-analysis of prospective cohort studies

The objective of the study was to assess the relationship between hypertension and risk of depression. The relationship between hypertension and depression has been discussed for a long time, but the results are controversial. Studies were searched from PubMed and Cochrane up to 24 March 2014. Any prospective cohort study, which possibly reported the relationship between hypertension and depression, was included. The random effect model was used to calculate the pooled relative risk (RR). Finally, five prospective cohort studies were included for analysis, with a total of 9647 participants involved. Our meta-analysis does not support that hypertension is probably a risk factor of depression. The pooled RR was 1.16 (95% confidence interval: 0.91, 1.42) when those exposed to hypertension were compared with those who were not. Subgroup analysis, sensitivity analysis and publication bias test suggested that the overall result of this analysis was robust. Further studies are needed to exclude the effects of other confounding factors.

The role of TGF-β1-miR-21-ROS pathway in bystander responses induced by irradiated non-small-cell lung cancer cells

Background:

Many studies have indicated an important implication of radiation-induced bystander effects (RIBEs) in cancer radiotherapy, but the detailed signalling remains unclear.

Methods:

The roles of tumour growth factor-beta1 (TGF-β1) and miR-21 in medium-mediated RIBEs in H1299 non-small-cell lung cancer cells were investigated using DNA damage, changes in proliferation and levels of reactive oxygen species (ROS) as end points. SB431542, a specific inhibitor of TGF-β type 1 receptor kinases, was used to inhibit TGF-β1 pathways in irradiated and bystander cells. Exogenous miR-21 regulation was achieved through inhibitor or mimic transfection.

Results:

Compared with relative sham-radiation-conditioned medium, radiation-conditioned medium (RCM) from irradiated cells 1 h post radiation (1-h RCM) caused an increase in ROS levels and DNA damage in bystander cells, while 18-h RCM induced cell cycle delay and proliferation inhibition. All these effects were eliminated by TGF-βR1 inhibition. One-hour RCM upregulated miR-21 expression in bystander cells, and miR-21 inhibitor abolished bystander oxidative stress and DNA damage. Eighteen-hour RCM downregulated miR-21 of bystander cells, and miR-21 mimic eliminated bystander proliferation inhibition. Furthermore, the dysregulation of miR-21 was attenuated by TGF-βR1 inhibition.

Conclusions:

The TGF-β1–miR-21–ROS pathway of bystander cells has an important mediating role in RIBEs in H1299 cells.

Double-resonance enhanced intersubband second-order nonlinear optical susceptibilities in GaN/AlGaN step quantum wells

Second-order nonlinear optical susceptibilities for second harmonic generation (SHG) associated with intersubband transitions in GaN/AlGaN single quantum well and step quantum well have been studied theoretically by solving Schrödinger and Poisson equations self-consistently. The calculated results suggest that due to the very large polarization-induced field in the quantum well, the potential profile becomes asymmetrical, leading to large second-order susceptibilities. A high value about 4 × 10^-7 m/V can be obtained in single quantum well structure. Furthermore, by adopting step quantum well structure to increase the asymmetry degree of the potential profile and manipulate the energy levels for double-resonance, a significant enhancement of second-order susceptibility can occur in step quantum well. Specifically, the susceptibility can be as large as 4 × 10^-6 m/V with structure optimization, about an order of magnitude greater than that in single quantum well. The results indicate that nonlinear optical elements based on GaN/AlGaN step quantum wells are very promising for SHG in a wide range of wavelengths from telecommunication to mid-infrared, especially effective in longer wavelength.

Gas-phase chemistry of Mo, Ru, W, and Os metal carbonyl complexes

Metal carbonyl complexes were used for studying the gas-phase chemical behavior of Mo, Ru, W and Os isotopes with an on-line low temperature isothermal gas chromatography apparatus. Short-lived Mo and Ru isotopes were produced by a 252Cf spontaneous fission source. Short-lived nuclides of W and Os were produced using the heavy ion reactions 19F +159Tb and 165Ho, respectively. Short-lived products were thermalized in a recoil chamber filled with a gas mixture of helium and carbon monoxide. The carbonyls formed were then transported through capillaries to an isothermal chromatography column for study of the adsorption behavior as a function of temperature. On-line isothermal chromatography (IC) experiments on Teflon (PTFE) and quartz surfaces showed that short-lived isotopes of the listed elements can form carbonyl complexes which are very volatile and interact most likely in physical sorption processes. Deduced adsorption enthalpies of Mo and Ru carbonyls were − 38 ± 2 kJ/mol and − 36 ± 2 kJ/mol, respectively. These values are in good agreement with literature data, partly obtained with different chromatographic techniques. A validation of the applied Monte Carlo model to deduce adsorption enthalpies with Mo isotopes of different half-lives proved the validity of the underlying adsorption model. The investigations using a gas-jet system coupled to a heavy ion accelerator without any preseparator clearly showed the limitations of the approach. The He and CO gas mixture, which was directly added into the chamber, will result in decomposition of CO gas and produce some aerosol particles. After the experiment of 173W and 179Os in the heavy ion experiments, the Teflon column was covered by a yellowish deposit; the adsorption enthalpy of W and Os carbonyls could therefore not be properly deduced using Monte Carlo simulations.

Predictive value of miR-9 as a potential biomarker for nasopharyngeal carcinoma metastasis

Background:

Nasopharyngeal carcinoma (NPC) has a distinctive geographic distribution and is characterised by its strong tendency of metastasis. We aimed to examine the microRNA (miRNA) expression profiles in plasma samples of NPC patients to explore their clinical significance in disease development and progression.

Methods:

This study was divided into four steps: (1) confirmation of differentially expressed miRNAs using microarray analysis and quantitative PCR validation; (2) comparison of plasma miR-9 levels during NPC progression; (3) evaluation of the predictive performance of plasma miR-9 as a biomarker for NPC metastasis; and (4) comparison of plasma miR-9 levels between pre- and post-treatment samples.

Results:

Plasma microarray profiling identified 33 differentially expressed miRNAs between NPC patients and healthy volunteers. The significantly declined level of miR-9 in NPC patients was confirmed through two-stage validation. The low level of plasma miR-9 was significantly correlated with worse lymphatic invasion and advanced TNM stage. The plasma miR-9 could distinguish locoregional from metastatic NPC cases with a high sensitivity and specificity. Furthermore, the plasma miR-9 level was significantly elevated in post-treatment plasma compared with those pre-treatment samples.

Conclusion:

Our study reports that plasma miR-9 may serve as a useful biomarker to predict NPC metastasis and to monitor tumour dynamics.

Clinical features, STAT3 gene mutations and Th17 cell analysis in nine children with hyper-IgE syndrome in mainland China

Hyper-IgE syndrome (HIES) is a rare primary immunodeficiency disease characterized by eczema, recurrent staphylococcal aureus skin abscesses, pneumonia with pneumatocele formation, remarkably high serum IgE levels, eosinophilia and involvement of skeleton and connective tissues. Heterozygous signal transducer and activator of transcription 3 (STAT3) mutations were shown to be the cause of autosomal dominant HIES (AD-HIES). In this study, we diagnosed nine patients with HIES from 9 unrelated families on the basis of a National Institutes of Health (NIH) score of ≥40 points, sequenced the STAT3 gene of all nine patients, and quantified Th17 cells in peripheral blood of seven patients by flow cytometry in mainland China. All nine patients had characteristic manifestation of HIES with the range of NIH scores 45-77 points. STAT3 hot mutations V637M or R382W/Q were identified in five patients. We identified two novel heterozygous missense mutations (T620S and R609G) located in Src homology 2 (SH2) domain in two patients, respectively. In two other patients, no STAT3 mutations were found. Quantified Th17 cell numbers were markedly decreased or absent (0-0.28% of CD4(+) T cells) in six patients with STAT3 mutations and almost normal (0.53% of CD4(+) T cells) in one wild-type STAT3 patient compared with healthy controls (0.40-2.25% of CD4(+) T cells). These results suggest that not all patients with HIES who had NIH scores over 40 points carry STAT3 mutations, those whose Th17 cell numbers strikingly decreased probably had AD-HIES with STAT3 mutations.

An inductive signalling network regulates mammalian tooth morphogenesis with implications for tooth regeneration

Sequential and reciprocal epithelial-mesenchymal interactions, essential throughout such aspects of tooth morphogenesis as patterning, size and number of teeth, involves a well-ordered series of inductive and permissive signals that exert global control over cell proliferation, differentiation and organogenesis. In particular, growth factors, transcription factors and their corresponding receptors, as well as other soluble morphogens, make up a regulatory network at the molecular level that synergistically or antagonistically controls intra-/inter-cellular signal transduction during odontogenesis. This review summarizes recent advances in the study of crucial signalling pathways, for example of BMPs, Wnt, Notch, Shh and FGF, with emphasis on the potential integrated signalling network responsible for tooth formation. Our work probes into the complexity of these inductive signalling pathways to promote the understanding of tooth regeneration. Additionally, our study provides further insights into therapeutic strategies for various dental abnormalities in patterning and number, such as tooth agenesis and supernumerary teeth.

Generation 9 polyamidoamine dendrimer encapsulated platinum nanoparticle mimics catalase size, shape, and catalytic activity

Poly(amidoamine) (PAMAM) encapsulated platinum nanoparticles were synthesized and used as catalase mimics. Acetylated generation 9 (Ac-G9) PAMAM dendrimer with a molecular size around 10 nm was used as a template to synthesize platinum nanoparticles. The feeding molar ratio of Pt(4+) and Ac-G9 is 2048, and the synthesized platinum nanoparticle (Ac-G9/Pt NP) has an average size of 3.3 nm. Ac-G9/Pt NP has a similar molecular size and globular shape with catalase (~11 nm). The catalytic activity of Ac-G9/Pt NP on the decomposition of H2O2 is approaching that of catalase at 37 °C. Ac-G9/Pt NP shows differential response to the changes of pH and temperature compared with catalase, which can be explained by different catalytic mechanisms of Ac-G9/Pt NP and catalase. Ac-G9/Pt NP also shows horseradish peroxidase activity and is able to scavenge free radicals such as di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (DPPH). Furthermore, Ac-G9/Pt NP shows excellent biocompatibility on different cell lines and can down-regulate H2O2-induced intracellular reactive oxygen species (ROS) in these cells. These results suggest that dendrimers are promising mimics of proteins with different sizes and Ac-G9/Pt NP can be used as an alternative candidate of catalase to decrease oxidation stress in cells.

Mandibular coronoid fractures: treatment options

Fractures of the coronoid process are uncommon and can easily be missed. The purpose of this study was to classify the fracture patterns and explore the treatment options. This retrospective study included 39 patients with fractures of the mandibular coronoid process. Treatment protocols were developed based on the time of fracture, degree of mouth opening, location of the coronoid fracture, types of fracture, and other concomitant fractures. All patients were followed up for 12-60 months. Sixteen patients underwent conservative management and four of these patients developed progressive trismus, which improved significantly after removal of the coronoid process. Twenty-three patients underwent open reduction and internal fixation (ORIF) via the modified retromandibular approach. Follow-up data showed significant improvement in maximum mouth opening and symptoms (diet and pain) compared to their preoperative status. In summary, conservative management is first recommended for fractures of the coronoid process with minimal displacement or restriction of mouth opening. For patients with significant fracture displacement and limited mouth opening, or with concomitant fractures of the zygoma, zygomatic arch, or mandibular ramus, ORIF via the modified retromandibular approach through the anterior border of the parotid gland is an alternative treatment method.

Characterization of HLA-F polymorphism in four distinct populations in Mainland China

Currently, there is a lack of information on polymorphism of human leucocyte antigen-F (HLA-F) gene in ethnically diverse human populations. In this study, HLA-F allelic typing was performed for 690 individuals representing two southern Chinese Han populations (Hunan Han and Guangdong Han) and two northern Chinese populations (Inner Mongolia Han and Inner Mongolia Mongol), using polymerase chain reaction-sequence-specific priming (PCR-SSP) and PCR-sequencing methods. Our results showed that (i) HLA-F*01 : 01 predominated in each population with a frequency >0.94 and HLA-F*01 : 03 was relatively more common in the two northern Chinese populations with a frequency of approximately 0.05; (ii) both geographical and ethnical factors are related to HLA-F allelic distribution, as evidenced by the significant difference in HLA-F allelic distribution between the Hunan Han population and the two northern Chinese populations; (iii) significant linkage disequilibrium (LD) was observed for haplotype HLA-A*03-F*01 : 03 in three populations. In most cases, this haplotype extended to HLA-E*01 : 03; and (iv) Ewens-Watterson homozygosity statistic at the HLA-F locus did not depart significantly from expectation in each of the four populations. Our data revealed a low level of HLA-F allelic variation in Chinese populations, suggesting that HLA-F gene may have existed before some of the HLA-A polymorphism and have been evolving under neutrality.

Comparison of a paraspinal approach with a percutaneous approach in the treatment of thoracolumbar burst fractures with posterior ligamentous complex injury: a prospective randomized controlled trial

OBJECTIVE

This prospective randomized controlled study compared the efficacy and safety of two paraspinal muscle-sparing surgical approaches for the management of neurologically intact patients with thoracolumbar burst fractures and posterior ligamentous complex injuries.

METHODS

Patients were randomized to undergo either percutaneous (n=31) or paraspinal (n=30) fluoroscopically-guided pedicle screw-rod fixation, and were followed for ≥3 years. Preoperative postural reduction was attempted in all patients.

RESULTS

The percutaneous approach was associated with significantly less intraoperative blood loss and shorter duration of surgery and hospitalization, as well as less pain and better functional recovery at 3 months after surgery compared with the paraspinal approach. Paraspinal surgery resulted in significantly better correction of kyphosis and restoration of vertebral height compared with percutaneous surgery. There were no differences in long-term clinical outcomes between the two groups.

CONCLUSIONS

The minimally invasive percutaneous approach appears to be better in cases of successful postural reduction. The paraspinal approach results in better surgical correction and is, therefore, recommended for patients without successful postural reduction.

High resolution space quartz-flexure accelerometer based on capacitive sensing and electrostatic control technology

High precision accelerometer plays an important role in space scientific and technical applications. A quartz-flexure accelerometer operating in low frequency range, having a resolution of better than 1 ng/Hz(1/2), has been designed based on advanced capacitive sensing and electrostatic control technologies. A high precision capacitance displacement transducer with a resolution of better than 2 × 10(-6) pF/Hz(1/2) above 0.1 Hz, is used to measure the motion of the proof mass, and the mechanical stiffness of the spring oscillator is compensated by adjusting the voltage between the proof mass and the electrodes to induce a proper negative electrostatic stiffness, which increases the mechanical sensitivity and also suppresses the position measurement noise down to 3 × 10(-10) g/Hz(1/2) at 0.1 Hz. A high resolution analog-to-digital converter is used to directly readout the feedback voltage applied on the electrodes in order to suppress the action noise to 4 × 10(-10) g/Hz(1/2) at 0.1 Hz. A prototype of the quartz-flexure accelerometer has been developed and tested, and the preliminary experimental result shows that its resolution comes to about 8 ng/Hz(1/2) at 0.1 Hz, which is mainly limited by its mechanical thermal noise due to low quality factor.

Performance and microbial community in hybrid Anaerobic Baffled Reactor-constructed wetland for nitrobenzene wastewater

A process combining an Anaerobic Baffled Reactor (ABR) and a constructed wetland was employed to treat nitrobenzene wastewater. The overall performance was examined throughout long-term operation with a hydraulic retention time (HRT) of 24 h at 30±1 °C. The effluent nitrobenzene concentration of the ABR and constructed wetland was less than 4.81 and 1.94 mg/L, respectively, with an initial nitrobenzene concentration of 80 mg/L at the steady-state periods. The corresponding removal efficiencies were 97.02% and 73.93%, respectively. Moreover, 97.29% of aniline produced in the ABR could be removed in the subsequent wetland. The number of sequenced clones from each library was sufficient to cover archaea and eubacteria diversity at the species level and to obtain a representation of the total microbial diversity in the ABR. The predominant microbial populations in the ABR were identified as Pseudomonas putida, Methanosaeta concilii and Methanothrix soehngenii.

Characterization of HLA-E polymorphism in four distinct populations in Mainland China

In this study, human leukocyte antigen (HLA)-E allelic typing was performed for 690 individuals from two southern Chinese Han populations (Hunan Han and Guangdong Han) and two northern Chinese populations (Inner Mongolia Han and Inner Mongolia Mongol) using polymerase chain reaction-sequence-specific priming (PCR-SSP) method. Our data showed that (1) HLA-E*01:01 and HLA-E*01:03, but not E*01:04 allele, were detected in the four populations, HLA-E distribution differed significantly between each of the two southern Chinese Han populations and the Inner Mongolia Mongol population, and between Hunan Han population and Inner Mongolia Han population; (2) HLA-G*01:05N-A*30-E*01:01-C*06-B*13:02-DRB1*07 was a conserved extended haplotype in the Chinese Han populations; (3) five HLA-A-E haplotypes showed significant linkage disequilibrium (LD) in at least one population, including HLA-A*02-E*01:03 in populations except for the Inner Mongolia Mongol group, HLA-A*01-E*01:01 and HLA-A*30-E*01:01 in the Hunan Han and the Inner Mongolia Han populations, HLA-A*33-E*01:01 in the two southern Chinese Han populations and HLA-A*03-E*01:03 in the Inner Mongolia Mongol group; and (4) Ewens-Watterson homozygosity test showed a trend for balancing selection at the HLA-E locus in each of the four populations. Our data unraveled the peculiarity in terms of HLA-E allelic and haplotypic repertoire in four main ethnic groups in Mainland China, findings shown here are valuable for future studies of the potential role of HLA-E in allogeneic organ transplantation and HLA-linked disease association in related ethnic groups.

Hindered proton collectivity in 16(28)S12: possible magic number at Z=16

The reduced transition probability B(E2;0(gs)(+)→2(1)(+)) for (28)S was obtained experimentally using Coulomb excitation at 53 MeV/nucleon. The resultant B(E2) value 181(31) e(2)fm(4) is smaller than the expectation based on empirical B(E2) systematics. The double ratio |M(n)/M(p)|/(N/Z) of the 0(gs)(+)→2(1)(+) transition in (28)S was determined to be 1.9(2) by evaluating the M(n) value from the known B(E2) value of the mirror nucleus (28)Mg, showing the hindrance of proton collectivity relative to that of neutrons. These results indicate the emergence of the magic number Z=16 in the |T(z)|=2 nucleus (28)S.

High concentration powdered activated carbon-membrane bioreactor (PAC-MBR) for slightly polluted surface water treatment at low temperature

In this study, different concentrations of PAC combined with MBR were carried out to treat slightly polluted surface water (SPSW) at low temperature (10°C). Effects of PAC on the efficiencies of operation, treatment, and the performance of the process were investigated. It was found that the effluent quality, performance efficiency, resistance of shock load were all enhanced and chemical irreversible membrane fouling was reduced with increasing dosage of PAC in MBR. Only when the concentration of PAC which acted as biological carriers was high enough (i.g., 50 g/L), nitrification without initial inoculation in the filtration tank could start within 19 days and be completed within 35 days at 10°C. Fifty grams per liter PAC was the optimal dosage in MBR for stable and extended operation. Under this condition, mean removal efficiencies of ammonia nitrogen (NH(3)-N), dissolved organic carbon (DOC) and UV(254) were 93%, 75%, and 85%, respectively.

Qiliqiangxin improves cardiac function in spontaneously hypertensive rats through the inhibition of cardiac chymase

BACKGROUND

This study was designed to investigate the effects and mechanism of action of the traditional Chinese drug formula, qiliqiangxin (QLQX), on cardiac function in spontaneously hypertensive rats (SHRs).

METHODS

We evaluated the effects of oral high-dose (4 g/kg/day, n = 7) and low-dose (1 g/kg/day, n = 7) QLQX on cardiac function in SHRs aged between 8 compared to control, the 8-week-old Wistar-Kyoto (WKY) rats. Echocardiography was performed to evaluate cardiac function and hemodynamic parameters. Hematoxylin and eosin (HE) and Masson's trichrome staining were performed, and the expression of myocardial angiotensin (Ang)-converting enzyme, chymase, transforming growth factor (TGF)-β, and collagen-type I and III were evaluated with real-time reverse transcription-PCR. Myocardial chymase, Ang-converting enzyme (ACE), and Ang II activities were measured with radioimmunoassay (RIA) techniques. Cardiac mast cells were detected with toluidine blue staining.

RESULTS

In SHRs, the number of chymase enzyme-positive mast cells increased in the left ventricle (LV) compared with WKY rats. QLQX significantly decreased mast cell density and cardiac chymase levels, and it improved ejection fraction values and cardiac systolic function compared with vehicle. Moreover, QLQX decreased left atrial diameters and improved the E/A ratio. QLQX suppressed collagen-type I and III and TGF-β mRNA levels, and Ang II activity, in a dose-dependent manner. Whereas no difference in ACE activity was found between SHRs, chymase expression and activity were significantly decreased with QLQX.

CONCLUSIONS

These data suggest that QLQX improves both systolic and diastolic cardiac function in SHRs through downregulating the cardiac chymase signaling pathway and chymase-mediated Ang II production.

Rabbit model of primary hyperparathyroidism induced by high-phosphate diet

The objective of this study is to establish a new rabbit model of primary hyperparathyroidism (PHPT) induced by high-phosphate diet. One hundred twenty rabbits were divided into two groups of 60 each. The treatment group was fed a high-phosphate diet (Ca:P = 1:7) and the control group was given a normal animal diet (Ca:P = 1:0.7) for 1 to 6 mo. Serologic examinations, including parathyroid hormone (PTH), calcium and phosphorus levels, blood urea nitrogen, creatinine, and uric acid, and the histologic examination, including parathyroid, kidney, and bones, were performed at the end of each month for 6 mo. Compared with the control, serum PTH levels in the treatment groups were elevated at all six time points, whereas serum calcium levels were reduced, and serum phosphorus levels remain unchanged over the course of the first 3 mo. Serum calcium levels were increased, whereas serum phosphorus levels were reduced at 4, 5, and 6 mo. Parathyroid histopathological examination showed no change during the first month, whereas 60% of the animals exhibited mild hyperplasia starting at 2 mo, and 90% of the animals in the treatment group exhibited mild-to-moderate hyperplasia with gland enlargement starting from 3 mo through the end of the study. Histopathological examination of the kidneys showed no change at 1 mo, but focal parenchymal inflammation with calcium deposition was observed in the treatment groups at 2 to 6 mo. Fibrous tissue of the bone extended toward the cortex, and fibrosis was evident at the third month. The fibrous cells were found to be concentrated mainly on the inner and outer membranes of the bone cortex, and the amount of fibrous tissue increased as the disease progressed. We conclude that a new rabbit animal model of PHPT can be successfully created by the administration of a high-phosphate diet. This animal model can be used in various future studies related to PHPT.

Orthopaedic training in China

There is no unified national training system for orthopaedic surgeons in China. With such rapid progress in many aspects of life in China, there is an imminent need for improvement in the training of orthopaedic specialists. Since 2003 the orthopaedic community in Hong Kong has been working in collaboration with their colleagues in mainland China to develop a training system for orthopaedic surgery. We adopted the system from the Royal College of Surgeons of Edinburgh (RCSEd), setting up a trial centre in the Beijing Jishuitan hospital in 2006, with trainers and trainees attaining the standards set by RCSEd and the Hong Kong College of Orthopaedic Surgeons (HKCOS). This trial is ongoing, with the success of two trainees who passed the exit examination in 2010 and became the first Chinese orthopaedic surgeons with a joint fellowship of both the RCSEd and the HKCOS. Following this inaugural success, we are confident that China will develop a training system for orthopaedic surgeons to a consistently high international standard.

Epigenetic regulation of HIF-1α in renal cancer cells involves HIF-1α/2α binding to a reverse hypoxia-response element

Inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene underlies the majority of sporadic clear cell renal cell carcinomas (CCRCCs) and is also responsible for the hereditary VHL cancer syndrome. VHL loss of function results in constitutive stabilization of hypoxia-inducible factors (HIF-1α and HIF-2α) due to insufficient proteolysis in the presence of oxygen. This activates multiple genes relevant to tumorigenesis, allowing cells to acquire further mutations and undergo malignant transformation. However, the specific role of each HIF-α subunit in CCRCC tumorigenesis is not yet well understood. The current paradigm supports that in the first stages of CCRCC formation the stabilization of HIF-1α is dominant and this limits proliferation, but later on HIF-2α increases and this induces a more aggressive cell behavior. Understanding how this transition happens is highly relevant, as it may provide novel ways to treat these cancers. Here, we show that VHL inactivation in CCRCC cells results in HIF-1α/2α-dependent downregulation of HIF-1α mRNA through direct binding of either subunit to a reverse hypoxia-response element in the HIF-1α proximal promoter. This binding activates a series of repressive histone modification marks including histone 3 lysine 27 trimethylation (H3K27me3) to make the changes stable, and if overturned reduces CCRCC cell proliferation due to excessive HIF-1α expression level. Our findings thus help understand how HIF-α subunits influence each other and also reinforce the idea that epigenetic mechanisms are a key step of CCRCC progression.

Incommensurate spin-density wave order in electron-doped BaFe2 As2 superconductors

Neutron diffraction studies of Ba(Fe(1-x)Co(x))(2)As)(2) reveal that commensurate antiferromagnetic order gives way to incommensurate magnetic order for Co compositions between 0.056 < x < 0.06. The incommensurability has the form of a small transverse splitting (0, ± ε, 0) from the commensurate antiferromagnetic propagation vector Q(AFM) = (1,0,1) (in orthorhombic notation) where ε ≈ 0.02-0.03 and is composition dependent. The results are consistent with the formation of a spin-density wave driven by Fermi surface nesting of electron and hole pockets and confirm the itinerant nature of magnetism in the iron arsenide superconductors.

Intrapericardial pheochromocytoma

Pheochromocytoma is a catecholamine-secreting tumor. Most cases are intra-adrenal, and intrapericardial pheochromocytomas are extremely rare. We report a case of a 30-year-old woman with a seven-year history of hypertension. The concentration of blood noradrenaline was found to be elevated. Chest computed tomography scan showed a limited bulge in the superior border of the right atrium. Magnetic resonance imaging confirmed the existence of a tumor. Coronary arteriography detected a mass near the right atrium, which was nourished by an aberrant branch of the right coronary artery. After preoperative preparation, the patient underwent pericardial tumor resection. Postoperative recovery was uneventful and the patient was successfully discharged 20 days later.

Strain-Induced Elevation of the Spontaneous Polarization in BaTiO3 Thin Films

A manmade ferroelectric-paraelectric heterostructure, a BaTiO3 / SrTiO3 superlattice, was studied to explore the effect of strain on ferroelectricity. An atomically abrupt BaTiO3 / SrTiO3 superlattice was grown on a (001) SrTiO3 substrate by reactive molecular beam epitaxy. Both BaTiO3 and SrTiO3 layers were grown with their individual thicknesses less than the critical thickness for the formation of interfacial misfit dislocations, leaving the entire superlattice fully coherent with the substrate. This resulted in a uniformly and highly strained BaTiO3 layer to study the effect of strain on ferroelectricity. Quantitative high-resolution transmission electron microscopy was employed to examine the atomic positions of cations and anions in the strained BaTiO3 layers. It was found that the relative static displacement of cations (Ti4+, Ba2+) to anions (O2−) is larger than that of bulk BaTiO3. Our observation thus illustrates the strain-induced elevation of spontaneous polarization in BaTiO3 thin films.

Diversity of culturable ericoid mycorrhizal fungi of Rhododendron decorum in Yunnan, China

The diversity of ericoid mycorrhizal fungi isolated from Rhododendron decorum Franch. in Yunnan, southwestern China, was examined for the first time. In total 300 hair-root samples were collected from 13 R. decorum individuals in two adjacent wild population sites and one cultivated population site. Two hundred eighteen slow-growing isolates were obtained; the ability of some to form ericoid mycorrhiza was tested in vitro. One hundred twenty-five isolates formed hyphal structures morphologically corresponding to ericoid mycorrhiza, and these were determined by morphological and molecular means to belong to 12 fungal species. There were hardly any differences in species among the three sampled populations. The sequences of several isolates were similar to those of Oidiodendron maius and ericoid mycorrhizal fungi from Helotiales, accounting respectively for 18.4% and 24.8% of the total culturable ericoid mycorrhizal fungi assemblage. Dark septate endophytes were detected in the sampled hair roots by microscopy.

Quantitative diffusion tensor imaging for evaluation of motor function in patients with brain infarcts

OBJECTIVE

To evaluate the quantitative diffusion value in ipsilateral cerebral peduncle of patients with differing motor function abilities and analyse the thresholds discriminating the poor motor function disability.

METHOD

Twenty-nine patients who previously suffered stroke underwent diffusion tensor imaging examinations. Motor function was evaluated 8 months after the event. The ipsilateral apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of cerebral peduncle and ADC ratio and FA ratio of patients with different motor function scales were analysed.

RESULTS

The ipsilateral FA value and FA ratio were distinctly different in patients with different motor function scales, and significantly correlated with the motor function scales. There was no significant difference of ipsilateral ADC and ADC ratio, and neither had correlation with motor function scale. The patients with poor motor function scale could be discriminated by the cutoff value of ipsilateral FA of 0.453 and FA ratio of 0.623 with sensitivity of 90%, 75% and specificity of 88.9%, 88.9% respectively.

CONCLUSIONS

The ipsilateral FA value and FA ratio were feasible and better imaging indices in discriminating patients with poor motor function ability.