Static and Dynamical Properties of the Spin-1/2 Equilateral Triangular-Lattice Antiferromagnet Ba_{3}CoSb_{2}O_{9}

We present single-crystal neutron scattering measurements of the spin-1/2 equilateral triangular-lattice antiferromagnet Ba_{3}CoSb_{2}O_{9}. Besides confirming that the Co^{2+} magnetic moments lie in the ab plane for zero magnetic field and then determining all the exchange parameters of the minimal quasi-2D spin Hamiltonian, we provide conclusive experimental evidence of magnon decay through observation of intrinsic line broadening. Through detailed comparisons with the linear and nonlinear spin-wave theories, we also point out that the large-S approximation, which is conventionally employed to predict magnon decay in noncollinear magnets, is inadequate to explain our experimental observation. Thus, our results call for a new theoretical framework for describing excitation spectra in low-dimensional frustrated magnets under strong quantum effects.

Characterization of a new HLA-A allele, HLA-A*02:07:08, by cloning and sequencing

In this report, we present a novel HLA-A*02:07 allele, HLA-A*02:07:08. HLA-A*02:07:08 was identified in an individual of Han ethnicity in Hunan province, southern China. Following polymerase chain reaction-sequence-based typing (PCR-SBT), this new allele was further confirmed by cloning and sequencing. HLA-A*02:07:08 differs from HLA-A*02:07:01 by a single synonymous C to T substitution at nucleotide position 131 in exon 3.

Strategy of STAT3β cell-specific expression in macrophages exhibits antitumor effects on mouse breast cancer

Recent studies underscore the importance of crosstalk between tumor-associated macrophages (TAMs) and tumor cells in cancer progression and metastasis. In our study, AdCD68STAT3β, a recombinant adenovirus containing a STAT3β gene driven by CD68 macrophage-specific promoter, was used to suppress STAT3 and the downstream signaling pathways in TAMs. The results showed that STAT3β gene under the control of CD68 macrophage-specific promoter was only expressed in macrophages, which significantly inhibited the motility and invasion of breast cancer cells when co-cultured with 4T1 cells. Moreover, cell-specific STAT3β expression in TAMs extended survival of tumor-bearing mice and suppressed breast tumor growth, angiogenesis and metastasis, by regulating the crosstalk between tumor cells and TAMs. Therefore, our study provided a novel strategy for the antitumor effects of STAT3β.

Identification of a novel MICB allele, MICB*030, by cloning and sequencing

A novel MICB allele, MICB*030, has been identified in a healthy Chinese individual of Mongol ethnicity residing in northern China by polymerase chain reaction sequence-based typing (PCR-SBT) and confirmed by cloning and sequencing. MICB*030 was linked to HLA-B*35. Aligned with MICB*005:02, MICB*030 has a nonsynonymous adenine substitution at nucleotide position 50 in exon 3, leading to amino acid change from serine to arginine at codon 102 of the mature MICB molecule.

Sequence-based typing of HLA-A gene in 930 patients with nasopharyngeal carcinoma in Hunan province, southern China

In this study, we typed 930 cases of nasopharyngeal carcinoma (NPC) and 1134 normal controls recruited from Hunan province, southern China for human leukocyte antigen-A (HLA-A) locus by sequencing exons 2-4. Very significant associations between HLA-A*02:07, HLA-A*11:01 and NPC were established [25.7% vs 16.18%; odds ratio, OR (95% confidence interval, CI) = 1.79 (1.54-2.09), P < 0.0001 and 21.1% vs 30.42%, OR (95% CI) = 0.61 (0.53-0.70), P<0.0001, respectively]. Further analysis of the molecular basis underlying these associations suggests that cysteine (C) at codon 99 of α2-helix of HLA-A protein is probably deleterious and confers risk to NPC. Convincing evidence was uncovered for negative association of a rare allele in southern Chinese populations, HLA-A*31:01, with NPC [0.22% vs 2.12%, OR (95% CI) = 0.1 (0.04-0.28), P < 0.0001]. rs1059449-A, which encodes arginine (R) at codon 56 of α1-helix of HLA-A protein, was postulated to be crucial for such a pattern of negative association with NPC. A subset of NPC cases (N = 632) and normal controls (N=712) were tested for anti-virus capsid antigen (anti-VCA) immunoglobulin A (IgA), very significant difference in seropositivity for anti-VCA IgA was observed between the two groups [67.56% vs 6.46%, OR (95% CI) = 30.16 (21.42-42.46), P < 0.0001]. However, seropositivity for anti-VCA IgA did not correlate with HLA-A allelic typing in both groups.

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.

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.