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A Ti-based metallic glass matrix composite (MGMC), which contains abundant primary α′ and ω phases in dendrites, has a strong work-hardening ability. A significant martensitic transformation occurred during plastic deformation at 298 K, and deformation twins were produced at 77 K. Transformation-induced plasticity and twinning-induced plasticity enable MGMC to achieve prominent strength–plasticity synergy. At 298 K, the alloy exhibits a yield strength (YS) of 1140 MPa and a uniform elongation (UE) of 8.1%, while at 77 K, the YS increases to 1520 MPa, still maintaining a UE of 4.6%. The prediction models of the temperature dependent YS and martensite trigger stress (σ S I M ) in MGMC were established. The strengthening and toughening mechanisms provide a great theoretical guidance for the development of low-temperature high-performance MGMCs. [ABSTRACT FROM AUTHOR]

This study presents the results of a driving experiment study on spatiotemporal characteristics of drivers' fixation when entering a tunnel portal with different driving speeds. The study was performed during the daytime in a relatively long tunnel. Six experienced drivers were recruited to participate in the driving experiment. Experimental data of pupil area and fixation point position (from 200 m before the tunnel to the tunnel portal) were collected by non-intrusive eye-tracking equipment for three predetermined vehicle speeds (40 km/h, 60 km/h and 80 km/h). Fixation maps (color-coded maps showing distributed data) were created from fixation point position data to quantify visual behaviour changes. The results demonstrated that vehicle speed has a significant impact on pupil area and fixation zones. Fixation area and average pupil area had a significant negative correlation with vehicle speed during the daytime. Moreover, drivers concentrated more on the tunnel entrance portal, front road pavement and car control wheeling. The results revealed that the relationship between pupil area and vehicle speed fitted an exponential function. Limitations and future directions of the study are also discussed. [ABSTRACT FROM AUTHOR]

Indentation tests at various depths confirm that the scale factor, f, which was proposed to modify the Nix-Gao model, is governed only by intrinsic properties of materials, but the connection between f and intrinsic properties is still unknown. From this, a connection is established between f and pertinent parameters, such as activation volume, V, and theoretical strength, G. Moreover, considering the interaction between adjacent indentations, we define a critical scale factor feff to describe the strengthening interface, which is found proportional to indentation depth for the given material. It is also found that larger feff is preferred for high-strength high-entropy alloys and/or medium-entropy alloys than pure metals. Combining f and feff of Ni, CoNi, CoCrNi and FeCoCrNi metals and alloys, a model describing dislocation density distribution in indentation plastic zone is established, in which the plastic zone includes three parts, i.e., the indentation zone of equivalent conical indenter, the detectable dislocation enhancement region, and the low dislocation density region. The inconsonant trends of f and feff can be explained by the existing of dislocation saturation zone in the plastic zone. The gradient plastic zone model proposed here graphically depicts the dislocations motion, as well as its reinforcement effect. Furthermore, this model lends credence to modify the framework which describes the mechanical response of materials under nanoindentation. [ABSTRACT FROM AUTHOR]

To verify the feasibility of preparing fine equiaxed microstructure of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy through hot deformation of martensite, the isothermal compression tests with three temperatures 600 , 700 , 800 °C and three strain levels 0.7, 1.1, 1.8 were conducted and its concomitant dynamic recrystallization behavior is studied. As deformed at 700 and 800 °C, the constitutive curves reach the peak stress rapidly and then exhibit continuous softening behavior caused by dynamic recovery and recrystallization until a steady state is reached. The Arrhenius-type hot deformation kinetics model and an Avrami-type dynamic recrystallization kinetics model of martensitic microstructure are built, which generally exhibit satisfactory prediction performance. For the specimen deformed to the strain of 1.8 at 800 °C, full recrystallized microstructure was realized, and the weighted average diameter of α grains is only 1.1 μm. Its compressive yield strength and plasticity reach 1188 MPa and 39.7%, respectively, which shows marvelous high product of strength and plasticity as 47.2 GPa%. To sum up, it is an effective way to prepare fine equiaxed microstructure through hot deformation of martensite. However, the hot deformation process should be precisely controlled to suppress the coarsening of recrystallized grains. [ABSTRACT FROM AUTHOR]

The preparation of metallic glass matrix composites (MGMCs) requires rapid cooling rate under vacuum conditions, and the amorphous matrix is sensitive to high temperature. For the reasons given above, the process of traditional annealing is rarely chosen for MGMCs. In this work, the influence of high-temperature (i.e. higher than the glass transition temperature) annealing on Ti48Zr18V12Cu5Be17 MGMC was investigated. After high-temperature annealing, breakaway corrosion phenomenon induced by the oxidation matrix have been described. Different deformation mechanisms of the as-cast and annealed specimens upon compressive loading have been probed in the present work. And the microporous microstructure, which stems from oxidation and crystallization of the glass matrix, shows a failure characteristic of MGMCs after high-temperature annealing. [ABSTRACT FROM AUTHOR]

Provides information on a study that reported results of photothermal ionization spectroscopy for the shallow impurities in the InP layer grown by gas source molecular beam epitaxy. Methodology of the study; Results and discussion on the study; Conclusion.

Background and purpose: Fatal familial insomnia (FFI) is an autosomal dominant disease due to the D178N mutation of PRNP gene coupling with homozygous methionine (Met) at codon 129. It is generally considered that D178N mutation cases with 129 M/M homozygotes present as FFI, and 129 V/V as genetic CJD. However, the frequency of 129 Met alleles in Chinese population is much higher than that in Caucasians. This study aims to investigate the clinical features and genetic characteristics of Chinese D178N mutants in this genetic context. Methods: We reviewed the clinical and genetic features of seven D178N patients. The clinical data, genetic data, electroencephalogram (EEG), brain magnetic resonance imaging (MRI), polysomnography (PSG), CSF 14‐3‐3 protein examinations of the seven patients were analyzed. Results: The genotypes at codon 129 were all M/M. Four of the seven cases reported positive family history. Four patients were more likely the CJD phenotype and three were FFI phenotype according to the core clinical features. No major differences were found on the EEG, CSF 14‐3‐3 protein, and PSG presentations between this study and western studies. Novel neuroimaging findings were two patients had typical neuroimaging abnormalities of CJD and frontotemporal dementia, respectively. Conclusions: Unlike the western populations, the diverse phenotypical presentations of D178N mutants were not simply determined by the 129 genotypes in Chinese. The underlying modifying factors for phenotypical variations warrant further investigations. For those with atypical clinical and imaging features, genetic testing was important for final diagnosis. [ABSTRACT FROM AUTHOR]

We conducted a retrospective analysis to assess the toxicity and long-term survival of esophageal squamous cell carcinoma patients treated with three-dimensional conformal radiotherapy (3DCRT) or intensitymodulated radiotherapy (IMRT) versus conventional two-dimensional radiotherapy (2DRT). All data in the present study were based on four prospective clinical trials conducted at our institution from 1996 to 2004 and included 308 esophageal squamous cell carcinoma patients treated with 2DRT or 3DCRT/IMRT. Based on the inclusion and exclusion criteria, 254 patients were included in the analysis. Of these patients, 158 were treated with 2DRT, whereas 96 were treated with 3DCRT/IMRT. The rates of =Grade3 acute toxicity of the esophagus and lung were 11.5% versus 28.5% (P = 0.002) and 5.2% versus 10.8% (P = 0.127) in the 3DCRT/IMRT and 2DRT groups, respectively. The incidences of =Grade 3 late toxicity of the esophagus and lungs were 3.1% versus 10.7% (P = 0.028) and 3.1% versus 5.7% (P = 0.127) in the 3DCRT/IMRT and 2DRT groups, respectively. The 1-year, 3-year and 5-year estimated overall survival rates were 81%, 38% and 34% in the 3DCRT/IMRT group and 79%, 44% and 31% in the 2DRT group, respectively (P = 0.628). The 1-year, 3-year and 5-year local control rates were 88%, 71% and 66% in the 3DCRT/IMRT group and 84%, 66% and 60% in the 2DRT group, respectively (P = 0.412). Fewer incidences of acute and late toxicities were observed in esophageal squamous cell carcinoma patients treated with 3DCRT/IMRT compared with those treated with 2DRT. No significant survival benefit was observed with the use of 3DCRT/IMRT. [ABSTRACT FROM AUTHOR]

We demonstrate thermal noise limited and shot noise limited performance of ultra-stable diode laser systems. The measured heterodyne beat linewidth between such two independent diode lasers reaches 0.74 Hz. The frequency instability of one single laser approaches 1.0 × 10-15 for averaging time between 0.3 s and 10 s, which is close to the thermal noise limit of the reference cavity. Taking advantage of these two ultra-stable laser systems, we systematically investigate the ultimate electrical noise contributions, and derive expressions for the closed-loop spectral density of laser frequency noise. The measured power spectral density of the beat frequency is compared with the theoretically calculated closed-loop spectral density of the laser frequency noise, and they agree very well. It illustrates the power and generality of the derived closed-loop spectral density formula of the laser frequency noise. Our result demonstrates that a 10-17 level locking in a wide frequency range is feasible with careful design. [ABSTRACT FROM AUTHOR]

Fourier transform infrared photoconductivity spectra of Si donors in GaAs under magnetic field are presented in this paper. Four new spectral lines corresponding to the transitions from hydrogen-like ground state to the metastable states (510), (610), (710), and (810) under nonzero magnetic field were observed. The variational calculation model proposed by Barmby et al. was applied to the high-lying metastable states. The experimental data of the transition energies agree well with the variational results under high magnetic field and below the resonant polaron region. Deviations due to omitting the bound Landau continuum coupling in the trial wave function were found in the comparison at the low field region for the metastable states with higher Landau index. The ionization energies of the high-lying metastable states were also determined. [ABSTRACT FROM AUTHOR]

We conducted a retrospective analysis to assess the toxicity and long-term survival of esophageal squamous cell carcinoma patients treated with three-dimensional conformal radiotherapy ( 3DCRT) or intensity-modulated radiotherapy ( IMRT) versus conventional two-dimensional radiotherapy ( 2DRT). All data in the present study were based on four prospective clinical trials conducted at our institution from 1996 to 2004 and included 308 esophageal squamous cell carcinoma patients treated with 2DRT or 3DCRT/ IMRT. Based on the inclusion and exclusion criteria, 254 patients were included in the analysis. Of these patients, 158 were treated with 2DRT, whereas 96 were treated with 3DCRT/ IMRT. The rates of ≥Grade3 acute toxicity of the esophagus and lung were 11.5% versus 28.5% ( P = 0.002) and 5.2% versus 10.8% ( P = 0.127) in the 3DCRT/ IMRT and 2DRT groups, respectively. The incidences of ≥Grade 3 late toxicity of the esophagus and lungs were 3.1% versus 10.7% ( P = 0.028) and 3.1% versus 5.7% ( P = 0.127) in the 3DCRT/ IMRT and 2DRT groups, respectively. The 1-year, 3-year and 5-year estimated overall survival rates were 81%, 38% and 34% in the 3DCRT/ IMRT group and 79%, 44% and 31% in the 2DRT group, respectively ( P = 0.628). The 1-year, 3-year and 5-year local control rates were 88%, 71% and 66% in the 3DCRT/ IMRT group and 84%, 66% and 60% in the 2DRT group, respectively ( P = 0.412). Fewer incidences of acute and late toxicities were observed in esophageal squamous cell carcinoma patients treated with 3DCRT/ IMRT compared with those treated with 2DRT. No significant survival benefit was observed with the use of 3DCRT/ IMRT. [ABSTRACT FROM AUTHOR]

In order to achieve high frequency stability in ultra-stable lasers, the Fabry-Perot reference cavities shall be put inside vacuum chambers with large thermal time constants to reduce the sensitivity to external temperature fluctuations. Currently, the determination of thermal time constants of vacuum chambers is based either on theoretical calculation or time-consuming experiments. The first method can only apply to simple system, while the second method will take a lot of time to try out different designs. To overcome these limitations, we present thermal time constant simulation using finite element analysis (FEA) based on complete vacuum chamber models and verify the results with measured time constants. We measure the thermal time constants using ultrastable laser systems and a frequency comb. The thermal expansion coefficients of optical reference cavities are precisely measured to reduce the measurement error of time constants. The simulation results and the experimental results agree very well. With this knowledge, we simulate several simplified design models using FEA to obtain larger vacuum thermal time constants at room temperature, taking into account vacuum pressure, shielding layers, and support structure. We adopt the Taguchi method for shielding layer optimization and demonstrate that layer material and layer number dominate the contributions to the thermal time constant, compared with layer thickness and layer spacing. [ABSTRACT FROM AUTHOR]

Background. The KIT gene plays an important role in the pathogenesis of malignant melanoma (MM). In recent years, activating mutations in KIT have been recognized as oncogenic. A number of therapies have been established, which provide significant clinical benefits for patients with MM with KIT mutations. Thus, detection of KIT mutations can have profound therapeutic implications. Aim. To investigate KIT gene expression in MMs in Chinese Uyghur and Han patients with mutations in KIT, and to identify the clinical features associated with KIT mutations and c-KIT expression. Methods. In total, 105 MMs (56 from Uyghur and 49 from Han patients) were selected from patients in the Uyghur Autonomous region. Formalin-fixed, paraffin wax-embedded tumour sections were analysed for c-KIT expression using immunohistochemistry. Exons 11 and 13 of KIT were analysed for the presence of mutations using PCR amplification and DNA sequencing. Results. Of the 105 MMs, 13 (10 Han and 3 Uyghur) were found to have mutations in KIT. Thus, the frequency of KIT mutations in Han patients was significantly higher than that in Uyghur patients (P = 0.02). We detected c-KIT expression in 71.4% and 42.9% of the tumour tissue samples collected from the Uyghur and Han patients, respectively. Conclusion. In the Xinjiang Uyghur Autonomous Region in China, chronic suninduced damage MM is the most prevalent MM among Chinese Uyghur patients, whereas acral and mucosal MMs are the most prevalent in Uyghur patients. Mutations in the KIT gene do not correlate with c-KIT expression. [ABSTRACT FROM AUTHOR]

The present work built on a previous study of tillage trials, which found the effectiveness of least limiting water range (LLWR) as an indicator of soil organic carbon (SOC) mineralization under different tillage practices in a black soil of Northeast China in 2009. To improve the understanding of soil structure controls over SOC dynamics, a study was conducted to explore the relationship between LLWR, which was calculated based on soil bulk density and soil pore-size distribution, and the effects of LLWR, which was calculated based on soil bulk density and soil pore-size distribution on SOC mineralization following no tillage (NT) and mouldboard ploughing (MP). In contrast to MP, NT had a significantly greater volume of large macropores (>100 μm) at depths of 0–0·05 and 0·2–0·3 m, but a significantly lower volume of small macropores (30–100 μm) at depths of 0–0·05, 0·05–0·1, 0·1–0·2 and 0·2–0·3 m. The volume of meso- (0·2–30 μm) and micro-pores (<0·2 μm) at different depths under the two tillage practices were similar. Tillage-induced changes in soil bulk density and pore-size volumes affected the ability of soil to fulfil essential soil functions in relation to organic matter turnover. Soil pore-size distribution, especially small macropores greatly affected LLWR and there was a significant correlation between LLWR, which was calculated based on soil bulk density, and the proportion of small macropores. The proportion of small macropores were used to calculate LLWR instead of soil bulk density and the values for NT and MP soils ranged from 0·073 to 0·148 m3 water/m3 soil. Using the proportion of small macropores rather than bulk density in the calculation of LLWR resulted in more sensitive indications of SOC mineralization. Variation in the proportion of small macropores can help characterize the impacts of tillage practices on dynamics of LLWR and SOC sequestration. [ABSTRACT FROM PUBLISHER]

A mixture of several typical model compounds was chosen as the bio-oil model. Hydrogen production via catalytic steam reforming of model bio-oil in a two-stage reaction system was studied in this article. Quartz sand was used in the first-stage fluidized bed reactor for primary steam reforming, and Ni/modified dolomite was chosen as the catalyst in the second-stage fixed bed reactor for deep steam reforming. The main influential parameters, such as temperature, steam to carbon ratio, and weight hourly space velocity, were tested in this work. The optimum conditions on hydrogen production were obtained at 800°C; steam and carbon mole ratio, 12; and weight hourly space velocity, 1 h−1. In addition, there was a comparison between a two-stage reaction system and one-stage fixed bed reactor on the optimum condition. It was concluded that H2yield decreased 5.6% in the two-stage reaction system and 9.9% in the one-stage fixed bed reactor after 3 h reaction time; the maximum carbon deposition ratio was 1 and 0.44%, gaseous carbon selectivity dropped from 93.6 and 90.1% to 83.4 and 78.4%. The fresh catalyst as well as used catalyst were analyzed by scanning electron microscopy, which showed that the carbon deposition in the two-stage reaction system is less than that of the one-stage fixed bed reactor. [ABSTRACT FROM PUBLISHER]

Little is known about the risk factors associated with hepatitis B virus ( HBV) intrauterine transmission among HBsAg-positive mothers. We conducted a study in Taiyuan, China, including 1133 HBsAg-positive mothers and their babies. A total of 101 neonates had HBsAg and/or HBV DNA positive with an intrauterine transmission rate of 8.9%. Maternal menstrual irregularity ( OR = 4.95, 95% CI: 1.71, 14.33) and severe nausea during the first trimester ( OR = 1.86, 95% CI: 1.11, 3.09) were associated with an increased risk of intrauterine transmission, while caesarean delivery ( OR = 0.32, 95% CI: 0.20, 0.51) was associated with a decreased risk after adjusting for potential confounders. Maternal HBeAg positive was a strong independent predictor for intrauterine transmission ( OR = 2.56, 95% CI: 1.54, 4.27). A positive association between maternal HBV DNA levels and intrauterine transmission was suggested. Maternal HBIG administration during pregnancy, family history of HBV infection and premature rupture of membranes was not associated with the risk of intrauterine transmission. The study confirmed that maternal HBeAg positive was a risk factor and caesarean delivery was a protective factor for intrauterine transmission. The new findings associated with menstrual irregularity and severe nausea during the first trimester warrant further investigation. [ABSTRACT FROM AUTHOR]

Medulloblastoma is a heterogeneous diffuse neoplasm that can be highly disseminated, and is the most common malignant childhood brain tumor. Although multimodal treatments have improved survival rates for patients with medulloblastoma, these tumors are associated with high morbidity and mortality. New treatment strategies are urgently needed to improve cure rates and, importantly, to spare normal brain tissue from neurotoxicity and patients from life-long cognitive and functional deficits associated with current therapies. In numerous preclinical brain tumor models, neural stem cells (NSCs) have shown great promise as delivery vehicles for therapeutic genes. Here, we have used an established, genetically modified human NSC line (HB1.F3.CD) to deliver carboxylesterase (CE) to cerebellar tumor foci and locally activate the prodrug camptothecin-11 (CPT-11) (Irinotecan) to the potent topoisomerase I inhibitor SN-38. HB1.F3.CD NSC tumor tropism, intratumoral distribution and therapeutic efficacy were investigated in clinically relevant experimental models. Magnetic resonance imaging was used for in vivo tracking of iron nanoparticle-labeled NSCs, and to assess the therapeutic efficacy of CE-expressing HB1.F3.CD cells. As compared with controls, a significant decrease in tumor growth rate was seen in mice that received both NSCs and CPT-11 as their treatment regimen. Thus, this study provides proof-of-concept for NSC-mediated CE/CPT-11 treatment of medulloblastoma, and serves as a foundation for further studies toward potential clinical application. [ABSTRACT FROM AUTHOR]

Cancer is a complex disease involving multiple oncogenes with diverse actions. Inhibiting only one oncogene is unlikely to eliminate the malignancy of cancer cells. The goal of this study was to investigate whether synergistic effects can be achieved by combined silencing of two oncogenes, K-ras and Akt2, which are key players in the Ras/MAPK and PI3K/Akt signaling pathways. The pancreatic cancer cell line, Panc-1, was selected for these studies as it has elevated expression of K-ras and Akt2. Compared with inhibiting each oncogene alone, simultaneously silencing the two oncogenes with RNA interference (RNAi) more effectively inhibited Panc-1 cell proliferation and colony formation, induced a significantly higher percentage of apoptosis and resulted in greater inhibition of c-myc expression in vitro. Furthermore, when delivered by polyethyleneimine into Panc-1 tumors in nude mice, RNAi simultaneously targeting K-ras and Akt2 inhibited tumor growth more efficiently than RNAi targeting the individual oncogenes. Therefore, RNAi simultaneously silencing the oncogenes K-ras and Akt2 may offer potential opportunities for pancreatic cancer gene therapy.Cancer Gene Therapy (2009) 16, 227–236; doi:10.1038/cgt.2008.82; published online 24 October 2008 [ABSTRACT FROM AUTHOR]

To prevent carbon/carbon (C/C) composites from oxidation at high temperatures, a SiC whisker (SiCw) toughened MoSi2–SiC–Si coating was prepared on the C/C surface by a two step technique of slurry and pack cementation. Scanning electron microscopy (SEM) analysis shows that, with the content of SiCw increasing, the dimensions and frequency of cracks in the coating decrease obviously. At the same time, the thickness and compact degree of the coating reduce with the increase of the SiCw content. Oxidation tests show that, as the content of SiCw is 10 wt-%, the coating possesses a better anti-oxidation property, and the weight loss of the coated sample is only 08% after oxidation at 1773 K for 200 h. The weight loss of the as-coated C/C composites is primarily due to the reaction of the C/C matrix and oxygen diffusing through the penetration cracks and holes in the coating. [ABSTRACT FROM AUTHOR]

In this study, the moisture source/sink and long-distance moisture transport associated with the summer precipitation in the mid-lower reaches of the Yangtze River Valley (YRV) over China have been investigated based on both data analysis and numerical simulations using the regional climate model RegCM3. The study focused on both a case of the 1998 summer flood events and the interannual variation of summer precipitation during 1961–2005 in the YRV. The results show that (1) the low latitudinal band from the Bay of Bengal, Indochina Peninsula, South China Sea to the Philippine Island is the major moisture source region for the summer precipitation in the YRV; (2) an eastward moisture transport from the Bay of Bengal and a westward moisture transport from the Philippines Sea meet at the South China Sea, where a main water vapor channel forms and advances north-northwestward and turns northeastward in the vicinity of the eastern Tibetan Plateau and South China to the YRV; and (3) the long-distance moisture transport from the eastern Indian Ocean-South China Sea to the YRV contributes to more than half of the summer precipitation in the YRV. Furthermore, it is shown that RegCM3 driven by the NCEP/NCAR reanalysis is able to reproduce the overall climatological water vapor transport in East Asia and the features of the water vapor flux for flooding and drought years in the YRV as well as simulate the YRV flood events in the summer of 1998 reasonably well. [ABSTRACT FROM AUTHOR]

Specific heat capacities of π meson and different quarks after parton cascade AMPT model in Au+Au collisions at $\sqrt{^SNN} = 200\ {\rm GeV}$ have been tentatively extracted from the event-by-event temperature fluctuations in the region of low transverse mass. The specific heat capacity of π meson shows a slight dropping trend with increasing impact parameter. The specific heat capacities of different quarks increase with the mass of quark, and the sum of up and down quark's specific heat capacities was found to be approximately equal to that of π meson. [ABSTRACT FROM AUTHOR]

Aims To investigate the prevalence of the Gly482Ser polymorphism of the PPARGC1 gene in a northern Chinese population and to clarify the susceptibility of individuals with the Gly482Ser polymorphism to insulin resistance and related diseases. Methods We studied the association of the Gly482Ser polymorphism identified in the PPARGC1 gene with Type 2 diabetes mellitus (T2DM) in 390 unrelated patients with T2DM and 525 control subjects with normal glucose tolerance. Clinical parameters and measures of insulin resistance were recorded. Genotypes were determined by the polymerase chain reaction—restriction fragment length polymorphism (PCR-RFLP) method, which was further confirmed by direct sequencing in 20 randomly selected cases. Results The Gly482Ser polymorphism was common in the northern Chinese population. Univariate analysis indicated no statistically significant differences in allele frequencies or genotype frequencies of the Gly482Ser polymorphism in diabetic and control subjects (minor 482Ser allele frequency 44.4 vs. 41.4%, P = 0.169). However, logistic regression analysis demonstrated a positive 1.645-fold higher risk of the Ser/Ser genotype for T2DM (P = 0.039, 95% CI = 1.026-2.632). After stratification by gender, the risk of Type 2 diabetes in men was increased 1.852-fold (95% CI = 1.125-3.049) in those with the Ser/X genotype compared with those with the Gly/Gly genotype (P = 0.015). No associations were observed between the Gly482Ser polymorphism and parameters of insulin resistance, obesity and hypertension. Conclusion The Gly482Ser variant of the PPARGC1 gene might contribute to susceptibility to T2DM in northern Chinese subjects. The Ser/X genotype of the Gly482Ser polymorphism in the PPARGC1 gene appears to be a risk factor for T2DM in northern Chinese men. [ABSTRACT FROM AUTHOR]

Far-infrared absorption spectra of Cz–Si grown under a reduced pressure of high pure nitrogen atmosphere have been investigated at different temperatures. Seven new series of lines resulting from the ground state splitting of N–O complexes [D(N–O)s] have been observed. The results indicate that the D(N–O)s have different structures. In addition, according to effective mass approximation, the binding energies of the split ground states have been obtained. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The p-type activation of arsenic (As) in (211)B mercury cadmium telluride (HgCdTe) grown by molecular beam epitaxy (MBE), with different compositions covering the 3–5 and 8–14 μm atmospheric transmission windows and after annealing at 300 °C is reported. The composition and thickness of the MBE layers were determined from Fourier transform infrared transmission measurements at room temperature. The ionization energies of shallow acceptors related to As in MBE HgCdTe layers with different Cd compositions have been obtained by fitting variable temperature Hall measurement results to a two-band nonparabolic Kane model. The results indicate that As incorporated during the MBE growth can be activated to provide a shallow acceptor level in MBE HgCdTe and the ionization energy of the As acceptor decreases with decreasing Cd composition, in agreement with the theory. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Magneto-photoconductivity spectra related to the bound phonons and resonant polaron effect on Si donors in high-purity InP have been investigated. Not only the transition from the 1s ground state to bound phonon state (1s+LO) of Si donors, but also the antilevel crossings of the (3, 1, 0) metastable state with the bound phonon states (1s+LO) and (2p[sub -1]+LO) are clearly observed in high magnetic fields. The results demonstrate the bound phonon in Si-doped InP consists of both electron and phonon via multiphonon processes and there is a resonant interaction between LO phonons and impurity-bound electrons in InP. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]