A distributed data processing scheme based on Hadoop for synchrotron radiation experiments

With the development of synchrotron radiation sources and high-frame-rate detectors, the amount of experimental data collected at synchrotron radiation beamlines has increased exponentially. As a result, data processing for synchrotron radiation experiments has entered the era of big data. It is becoming increasingly important for beamlines to have the capability to process large-scale data in parallel to keep up with the rapid growth of data. Currently, there is no set of data processing solutions based on the big data technology framework for beamlines. Apache Hadoop is a widely used distributed system architecture for solving the problem of massive data storage and computation. This paper presents a set of distributed data processing schemes for beamlines with experimental data using Hadoop. The Hadoop Distributed File System is utilized as the distributed file storage system, and Hadoop YARN serves as the resource scheduler for the distributed computing cluster. A distributed data processing pipeline that can carry out massively parallel computation is designed and developed using Hadoop Spark. The entire data processing platform adopts a distributed microservice architecture, which makes the system easy to expand, reduces module coupling and improves reliability.

[Consideration on the construction of a special research database for human papillomavirus vaccination in high-risk and special populations]

The application of human papillomavirus (HPV) vaccine in China has accelerated in recent year. Women's and Children's hospitals as well as general hospitals have established HPV vaccination counselling clinic in succession. A large amount of valuable preventive and clinical data have been generated in the evaluation, recommendation, immunization and management of HPV vaccine for high-risk and special populations. This article sorted out the operation process of HPV vaccination counselling clinic, discussed the methods for hospitals to construct a special research database for HPV vaccination in high-risk and special populations under different degrees of informatization. It also provided a reference for the establishment of unified data standards, the formation of available data resources, and the promotion of real world study on HPV vaccination for high-risk and special populations in China.

[Determination of acetylacetone in workplace air by solvent desorption-gas chromatography]

Objective: To establish a method for the determination of acetylacetone in the air of workplace by gas chromatography. Methods: In August 2020, acetylacetone in the air of workplace was collected by silica gel tube, eluted with methanol, separated and detected by gas chromatography with flame ionization detector. The detection limit and precision of the method were also analyzed. Results: The linear range of acetylacetone was 1.95-1950.60 μg/ml with the regression equation of y=0.815x-3.667, and the correlation coefficient was 0.99993. The limit of detection of the method was 0.18 μg/ml and the minimum detection concentration was 0.12 mg/m(3) (collected sample volume was 1.50 L). The within-run precisions were 1.08%-4.11% and the between-run precisions were 1.98%-2.80%. The desorption rates were 99.68%-100.45%. The sealed samples could be kept at least 15 days at room temperature without significant loss. Conclusion: The solvent desorption-gas chromatography method for the determination of acetylacetone has good precision, high sensitivity and simple operation, and is suitable for the determination of acetylacetone in the air of the workplace.

[The method of determination for butyronitrile and isobutyronitrile in the air of workplace by dissolved desorption-gas chromatography]

Objective: To establish a method for the determination of butyronitrile and isobutyronitrile in the air of workplace by gas chromatography. Methods: In March 2020, butyronitrile and isobutyronitrile in the air of workplace was collected by silica gel, eluted with methanol, separated and determined by gas chromatogram with flame ionization detector, the characteristics of determination of nitrile and isobutyronitrile by gas chromatography were analyzed. Results: The limit of detection for butyronitrile and isobutyronitrile was 0.33 μg/ml. The linear range of butyronitrile determined by this method was 1.60-1600.00 μg/ml, y=2.295x-3.480, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.43%-4.12%, the between-run precisions were 1.72%-3.70%, and the desorption rates were 93.26%-98.41%. The linear range of isobutyronitrile determined by this method was 1.52-1520.00 μg/ml, y=2.208x-0.102, and the coefficient correlation was 0.99998, and the minimum detection concentration was 0.22 mg/m(3) (collected sample volume was 1.50 L) . The within-run precisions were 2.52%-3.22%, the between-run precisions were 1.20%-3.82%, and the desorption rates were 96.85%-102.50%. The sealed samples could be stored at least 10 days at room temperature without significant loss. Conclusion: The method has the advantages of good precision, high sensitivity and simple operation. It is suitable for the simultaneous determination of butyronitrile and isobutyronitrile in the air of workplace.

[Research progress on the application of time-restricted eating in adult obesity and related metabolic diseases]

The soaring prevalence of obesity and its complications presents a significant health care burden, and there is currently a lack of effective and sustainable treatment methods. Time-restricted eating (TRE) is a specific intermittent fasting (IF) protocol involving consistent fasting and eating periods within a 24-hour cycle. Time-restricted eating can restore robust circadian rhythms and improve metabolic health, providing an emerging dietary strategy for the prevention and treatment of obesity and related metabolic diseases. Previous TRE trials laid the groundwork, and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy and the mechanisms by which it may affect humans.

Proper motility enhances rumen fermentation and microbial protein synthesis with decreased saturation of dissolved gases in rumen simulation technique

The physiological function of the reticulorumen plays an essential role in ruminant nutrition, and detailed knowledge of rumen motility can further advance understanding of ruminant nutrition and physiology. Rumen motility was simulated by setting different stirrer rotation speeds in a rumen simulation technique (RUSITEC) system. The aim of this study was to investigate the effects of rotation speeds on rumen fermentation, saturation factor of dissolved gases, hydrogen (H₂) and methane (CH₄) emissions, microbial protein synthesis, and selected microbial population using RUSITEC. The experiment was performed according to a balanced 3 × 3 Latin square design, and each period included 7 d for adaptation and 3 d for sampling. Three motility treatments included 5, 15, and 25 rpm rotation speeds. Daily total gas and H₂ and CH₄ emissions had quadratic responses to the increasing rotation speed and were highest at 15 rpm. Quadratic and linear responses (highest at 5 rpm) to increasing rotation speed were observed for saturation factors of H₂ and CH₄, liquid-dissolved H₂ and CH₄ concentrations, and headspace concentration of H₂ in the gas phase, whereas increasing rotation speed linearly decreased saturation factors of CO₂ and liquid-dissolved CO₂ concentration. Quadratic and linear responses to increasing rotation speed were observed for molar percentages of acetate, ammonia, and microbial protein concentration, whereas increasing rotation speed quadratically increased pH and decreased total volatile fatty acid concentration and acetate-to-propionate ratio. The 15-rpm rotation speed had the highest values of total volatile fatty acids, acetate molar percentage, and microbial protein concentration. Quadratic and linear responses to increasing rotation speed were observed for copy numbers of solid-associated fungi and fluid-associated bacteria, fungi, and protozoa, while increasing rotation speed linearly increased copy numbers of solid-associated protozoa. Rotation at 15 rpm increased populations of fungi and protozoa in the solid rumen contents and the population of bacteria and fungi in the liquid rumen contents. In summary, this study provides insights on the biofunction of proper rumen motility (i.e., at a rotation speed of 15 rpm), such as improving feed fermentation, increasing gas emissions with decreased dissolved gas concentrations and saturation factors, and promoting microbial colonization and microbial protein synthesis, although further increase in rotation speed (i.e., to 25 rpm) decreases feed fermentation and microbial protein synthesis.

Complex crystal structure determination and anti-non-small-cell lung cancer activity of the Hsp90N inhibitor Debio0932

Debio0932 is a promising lead compound in phase I clinical trials targeting the N-terminal ATP-binding pocket of the molecular chaperone heat-shock protein 90 (Hsp90^N). The absence of a crystal structure of the Hsp90^N-Debio0932 complex, however, has impeded further structural optimization of Debio0932 and understanding of the molecular-interaction mechanism. Here, a high-resolution crystal structure of the Hsp90^N-Debio0932 complex was successfully determined (resolution limit 2.20 Å; PDB entry 6lr9) by X-ray diffraction and the molecular-interaction mechanism was analysed in detail, which suggested that Debio0932 suppresses cancer cells by accommodating itself in the ATP-binding pocket of Hsp90^N, disabling its molecular-chaperone capability. The results of a thermal shift assay (ΔT_m = 8.83 ± 0.90°C) and isothermal titration calorimetry (K_d = 15.50 ± 1.30 nM) indicated strong binding and favourable thermodynamic changes in the binding of Hsp90^N and Debio0932. Based on the crystal structure of the complex and on molecular-interaction analysis, 30 new Debio0932 derivatives were designed and nine new derivatives exhibited increased binding to Hsp90^N, as determined by molecular-docking evaluation. Additionally, Debio0932 suppressed cell proliferation (IC₅₀ values of 3.26 ± 2.82 µM for A549, 20.33 ± 5.39 µM for H1299 and 3.16 ± 1.04 µM for H1975), induced cell-cycle arrest and promoted apoptosis in three non-small-cell lung cancer (NSCLC) cell lines. These results provide novel perspectives and guidance for the development of new anti-NSCLC drugs based on the lead compound Debio0932.

[Application of a new solid adsorbent tube for the determination of three kinds of epoxy eompounds in air]

Objective: To develop a new solid sorbent tube for simultaneously capturing ethylene oxide (EO) , propylene oxide (PO) and epichlorohydrin (ECH) in air, and establish a complete set of method. Methods: In June 2018, EO, PO and ECH in air were captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 5% (V/V) methanol-methylene chloride, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EO, PO and ECH were 0.24-960.00, 0.60-2384.00 and 0.12-472.40 mg/L respectively, and the related coefficients were between 0.99995-0.99997. The relative standard deviations (RSD) within the group were 1.66%-4.09%, 1.36%-4.43%, and 1.99%-5.65%, respectively, and the RSD between the group were 2.69%-4.95%, 2.77%-5.30%, and 3.27%-6.67%, respectively. The average desorption efficiencies were 88.25%-94.50%, 98.17%-98.60%, and 97.79%-101.04%, respectively. The samples could be stored at 4 ℃ refrigerator for at least 27 days. Conclusion: The newly developed solid sorbent tube filled with carbon aerogel adsorbent and its complete set of gas chromatography method could be used for sampling and quantitative detection of EO, PO and ECH in workplace air.

Modulation of rumen fermentation and microbial community through increasing dietary cation-anion difference in Chinese Holstein dairy cows under heat stress conditions

AIMS

The effect of increasing dietary cation-anion difference (DCAD) on rumen fermentation and ruminal microbial community in dairy cows under heat stress (HS) conditions were evaluated.

METHODS AND RESULTS

This study was performed as a two-period cross-over design during the summer season, with eight lactating dairy cows randomly distributed to either a control DCAD diet (CON: 33·5 mEq/100 g DM) or high DCAD diet (HDCAD: 50·8 mEq/100 g DM). Throughout the present study, the temperature and humidity index (THI; 80·2 ± 4·29) was generally elevated above the threshold (THI = 72) that is reported to cause HS in lactating dairy cows. Rumen liquid samples were collected on 15 and 21 d during each 21 d-period. The absolute concentration of ruminal total volatile fatty acid (TVFA) in HDCAD treatment was significantly (P < 0·05) higher than those in the control, whilst the ruminal pH, NH₃ -N, and VFA molar percentages were unaffected through increasing DCAD. Furthermore, the copy numbers of the cellulolytic bacteria Ruminococcus albus and Ruminococcus flavefaciens in rumen fluid significantly (P < 0·05) rose along with the increment of DCAD. Although the Alpha diversity indexes and the bacterial microbiota structure were unaffected, increasing DCAD significantly (P < 0·05) enriched the phylum Fibrobacteres and genus Fibrobacter in the microflora of rumen fluid, whilst the genera Flexilinea and Dubosiella were the most differentially abundant taxa in the control.

CONCLUSIONS

Increasing DCAD under HS conditions resulted in a greater concentration of total VFA without affecting rumen bacteria diversity or structure, although the enrichment of some cellulolytic/hemicellulolytic bacteria was observed.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study provides information on the modulation of rumen fermentation and microbial community through the increment of DCAD in Holstein dairy cows under HS conditions.

Corn oil supplementation enhances hydrogen use for biohydrogenation, inhibits methanogenesis, and alters fermentation pathways and the microbial community in the rumen of goats

Enteric methane (CH4) emissions are not only an important source of greenhouse gases but also a loss of dietary energy in livestock. Corn oil (CO) is rich in unsaturated fatty acid with >50% PUFA, which may enhance ruminal biohydrogenation of unsaturated fatty acids, leading to changes in ruminal H2 metabolism and methanogenesis. The objective of this study was to investigate the effect of CO supplementation of a diet on CH4 emissions, nutrient digestibility, ruminal dissolved gases, fermentation, and microbiota in goats. Six female goats were used in a crossover design with two dietary treatments, which included control and CO supplementation (30 g/kg DM basis). CO supplementation did not alter total-tract organic matter digestibility or populations of predominant ruminal fibrolytic microorganisms (protozoa, fungi, Ruminococcus albus, Ruminococcus flavefaciens, and Fibrobacter succinogenes), but reduced enteric CH4 emissions (g/kg DMI, -15.1%, P = 0.003). CO supplementation decreased ruminal dissolved hydrogen (dH2, P < 0.001) and dissolved CH4 (P < 0.001) concentrations, proportions of total unsaturated fatty acids (P < 0.001) and propionate (P = 0.015), and increased proportions of total SFAs (P < 0.001) and acetate (P < 0.001), and acetate to propionate ratio (P = 0.038) in rumen fluid. CO supplementation decreased relative abundance of family Bacteroidales_BS11_gut_group (P = 0.032), increased relative abundance of family Rikenellaceae (P = 0.021) and Lachnospiraceae (P = 0.025), and tended to increase relative abundance of genus Butyrivibrio_2 (P = 0.06). Relative abundance (P = 0.09) and 16S rRNA gene copies (P = 0.043) of order Methanomicrobiales, and relative abundance of genus Methanomicrobium (P = 0.09) also decreased with CO supplementation, but relative abundance (P = 0.012) and 16S rRNA gene copies (P = 0.08) of genus Methanobrevibacter increased. In summary, CO supplementation increased rumen biohydrogenatation by facilitating growth of biohydrogenating bacteria of family Lachnospiraceae and genus Butyrivibrio_2 and may have enhanced reductive acetogenesis by facilitating growth of family Lachnospiraceae. In conclusion, dietary supplementation of CO led to a shift of fermentation pathways that enhanced acetate production and decreased rumen dH2 concentration and CH4 emissions.

[Simultaneous determination of four kinds methyl acrylate compounds in workplace air]

Objective: To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air. Methods: MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m(3), 0.10 mg/m(3), 0.07 mg/m(3) and 0.07 mg/m(3) respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days. Conclusion: This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.

[Effects of calcineurin gene silencing on the remodeling of transient outward potassium current ionic channel in hypertrophic ventricular myocytes from neonatal rats]

Objective: To investigate the effects of calcineurin gene silencing on the remodeling of transient outward potassium current (Ito) ionic channel and action potential duration (APD) in phenylephrine (PE)-induced hypertrophic ventricular myocytes from neonatal rats. Methods: The ventricular myocytes of 1-day-old Sprague-Dawley rats were isolated and cultured for 48 h. RNA interference mediated by adenovirus carrying short hairpin RNA was used to knock down the gene which encodes the beta subtype of calcineurin A subunit (CnAβ) and the cells were divided into 4 groups as Ad-null group, Ad-null+ PE group, Ad-CnAβshRNA1(A1) group and A1+ PE group, and then cultured for 48 h. The gene expression of Kv4.2 was assayed by real-time reverse transcriptase-polymerase chain reaction. The protein expressions of CnAβ and Kv4.2 were assayed by Western blot test. Whole cell patch clamp technique was used to record Ito and action potential. Results: Treatment of the neonatal rat ventricular myocytes with PE induced the cell hypertrophy, up-regulated the protein expression of CnAβ, attenuated the gene and protein expressions of Kv4.2 and the Ito current density, and prolonged APD. Silencing of CnAβ in the neonatal rat ventricular myocytes using Ad-CnAβshRNA1 inhibited the aforementioned ability of PE significantly. Conclusion: CnAβ gene silencing inhibits the remodeling of transient outward potassium current ionic channel and change of APD in PE-induced hypertrophic ventricular myocytes from neonatal rats.

[Determination of volatile organic compounds in air by portable gas chromatography-mass spectroscopy]

Objective: To investigate the method of portable gas chromatography-mass spectroscopy (GC-MS) for the determination of common volatile organic compounds in air. Methods: The static volumetric method was used, with highly purified nitrogen gas as the diluents gas, to prepare the mixed standard gas of common volatile organic compounds with various mass concentrations. A portable GC-MS handheld probe was used for sampling and measurement, retention time and characteristic ion were used for qualitative analysis, and the full-scan mode was used for quantitative analysis. Results: The correlation coefficient of 12 volatile organic compounds determined by this method was higher than 0.999. The minimum detection mass concentration was 0.02~0.12 mg/m³, and the minimum quantitative mass concentration was 0.07~0.40 mg/m³. The relative standard deviation of precision was 4.10%~12.50%; the relative deviation of acetone, benzene, methylbenzene, and dimethylbenzene was-13.56% , 9.03% , -10.82% , and 8.67% , respectively. Conclusion: Portable GC-MS method can be used for the qualitative analysis and quantification of volatile organic compounds in occupational hazard factors and provide technical supports for identification of occupational hazard factors.

Resveratrol induces antioxidant and heat shock protein mRNA expression in response to heat stress in black-boned chickens

This study investigated the effects of dietary resveratrol at 0, 200, 400, or 600 mg/kg of diet on the performance, immune organ growth index, serum parameters, and expression levels of heat shock protein (Hsp) 27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius, thymus, and spleen of 42-d-old female black-boned chickens exposed to heat stress at 37 ± 2°C for 15 d. The results showed that heat stress reduced daily feed intake and BW gain; decreased serum glutathione (GSH), growth hormone, and insulin-like growth factor-1 levels; and inhibited GSH peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT) activities compared with birds subjected to thermo-neutral circumstances. Chickens that were fed diets supplemented with resveratrol exhibited a linear increase in feed intake and BW gain (P < 0.001); serum GSH, growth hormone, and insulin-like growth factor-1 levels (P ≤ 0.01); and GSH-Px, SOD, and CAT activities (P < 0.001) compared with chickens that were fed diets without resveratrol during heat stress. In contrast, serum malonaldehyde concentrations were decreased (P < 0.001) in the chickens fed a resveratrol-supplemented diet. Heat stress also reduced (P < 0.05) the growth index of the bursa of Fabricus and spleen; however, it had no effect on the growth index of the thymus. The growth index of the bursa of Fabricius and spleen increased (P < 0.05) upon heat stress and coincided with an increase in supplemental resveratrol levels. The expression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen were increased (P < 0.01), but those of Hsp27 and Hsp90 mRNA in thymus were decreased (P < 0.01) under heat stress compared with no heat stress. Resveratrol attenuated the heat stress-induced overexpression of Hsp27, Hsp70, and Hsp90 mRNA in the bursa of Fabricius and spleen and increased the low expression of Hsp27 and Hsp90 mRNA in thymus upon heat stress. The results suggest that supplemental resveratrol improves growth performance and reduces oxidative stress in heat-stressed black-boned chickens by increasing serum growth hormone concentrations and modulating the expression of heat shock genes in organs of the immune system.

Support vector machine-based nomogram predicts postoperative distant metastasis for patients with oesophageal squamous cell carcinoma

Background:

We aim to develop effective models for predicting postoperative distant metastasis for oesophageal squamous cell carcinoma (OSCC) for the purpose of guiding tailored therapy.

Methods:

We used data from two centres to establish training (n=319) and validation (n=164) cohorts. All patients underwent curative surgical treatment. The clinicopathological features and 23 immunomarkers detected by immunohistochemistry were involved for variable selection. We constructed eight support vector machine (SVM)-based nomograms (SVM1–SVM4 and SVM1'–SVM4'). The nomogram constructed with the training cohort was tested further with the validation cohort.

Results:

The outcome of the SVM1 model in predicting postoperative distant metastasis was as follows: sensitivity, 44.7% specificity, 90.9% positive predictive value, 81.0% negative predictive value, 65.6% and overall accuracy, 69.5%. The corresponding outcome of the SVM2 model was as follows: 44.7%, 92.1%, 82.9%, 65.9%, and 70.1%, respectively. The corresponding outcome of the SVM3 model was as follows: 55.3%, 93.2%, 87.5%, 70.7%, and 75.6%, respectively. The SVM4 model was the most effective nomogram in prediction, and the corresponding outcome was as follows: 56.6%, 97.7%, 95.6%, 72.3%, and 78.7%, respectively.Similar results were observed in SVM1', SVM2', SVM3', and SVM4', respectively.

Conclusion:

The SVM-based models integrating clinicopathological features and molecular markers as variables are helpful in selecting the patients of OSCC with high risk of postoperative distant metastasis.

Differentially expressed genes implicated in embryo abortion of mango identified by suppression subtractive hybridization

Embryo abortion in mango severely damages mango production worldwide. The mechanisms by which the mango embryos abort have long been an intriguing question. We used subtractive suppression hybridization to investigate the differentially expressed genes involved in this process. We generated 2 cDNA libraries from normal seed and aborted seed embryos of mango cultivar 'Jinhuang'. One thousand five hundred and seventy-two high-quality expressed sequence tags (ESTs) were obtained, with 1092 from the normal seed tester library and 480 from the aborted seed tester library. These ESTs were assembled into 783 unigenes, including 147 contigs and 636 singletons in contigs; 297 singletons in gene ontology (GO) indicated coverage of a broad range of GO categories. Seven candidate genes from different categories were selected for semi-quantitative PCR analysis, and their possible functions in embryo abortion are discussed. These data provide new insight into the genetic regulation of embryo abortion in mango and may aid in further identification of novel genes and their functions.

n-ZnO/LaAlO3/p-Si heterojunction for visible-blind UV detection

A visible-blind UV photodetector (PD) using a double heterojunction of n-ZnO/LaAlO3 (LAO)/p-Si was demonstrated. Inserted LAO layers exhibit electrical insulating properties and serve as blocking layers for photoexcited electrons from p-Si to n-ZnO, leading to an enhanced rectification ratio and a visible-blind UV detectivity of the n-ZnO/LAO/p-Si PDs due to the high potential barrier between LAO and p-Si layers (~2.0 eV). These results support the use of n-ZnO/LAO/p-Si PDs in the visible-blind UV PDs in a visible-light environment.

Solar energy harvesting scheme using syringe-like ZnO nanorod arrays for InGaN/GaN multiple quantum well solar cells

Syringe-like ZnO nanorod arrays (NRAs) synthesized by a hydrothermal method were applied as the light-harvesting layer on InGaN-based multiple quantum well (MQW) solar cells. Theoretical calculations show that the NRAs with an abrupt shrinkage of tip diameter can further suppress surface reflectance in comparison with the flat NRAs. InGaN-based MQW solar cells with the syringe-like NRAs exhibit greatly improved conversion efficiencies by 36%. These results are attributed to the improved flatness of the refractive index profile at the air/device interface, which results in enhanced light trapping effect on the device surface.

Contact behavior of focused ion beam deposited Pt on p-type Si nanowires

Pt contact on p-Si nanowires (NWs) using Ga-ion-induced deposition by a focused ion beam was formed with a specific contact resistance (rho(c)) of 1.54 x 10(-6) Omega cm(2). Ohmic behavior is caused by Ga-ion-induced amorphization of Si NWs underneath the Pt contact. A very low Schottky barrier height associated with interface states raised from Pt-amorphized Si junction and with an image force induced by the applied bias can be implemented to elucidate ultralow rho(c). The value of rho(c) lower than that of any known contact to Si NWs demonstrates a practical method for integrating NWs in devices and circuits.

A retrospective cohort study of nasopharyngeal adenocarcinoma: a rare histological type of nasopharyngeal cancer

OBJECTIVES

The purpose of this study was to investigate the clinical manifestations, Epstein-Barr virus (EBV) serology, and treatment outcome of patients with nasopharyngeal adenocarcinoma (NPAC).

DESIGN

A retrospective study of clinical data from consecutive patients with NPAC identified between 1964 and 2000.

SETTING

A tertiary cancer center in China.

PARTICIPANTS

Forty-eight patients diagnosed with NPAC.

MAIN OUTCOME MEASURES

Crosstabs and chi-square test were conducted to study the association of positive VCA-IgA levels among different pathological types of NPAC, and also to compare the proportions of local control rates in patients treated with different modalities. The survival rate was calculated using the Kaplan-Meier method, and the Log Rank test was used to compare the survival rates considering different factors. To balance the distribution bias, a multivariate COX model survival analysis was also performed.

RESULTS

Of the 48 NPAC patients identified, 45% presented with cervical metastasis. Pathologically, 58% of NPAC cases were common type and 42% were salivary gland type. The positive rate for the EBV antibody VCA-IgA in all patients was 53% and only 24% in the salivary gland type of NPAC. The overall local control rate and the 5-year disease-free survival rates were 87% and 65% respectively. Patients treated with surgery plus radiotherapy (RT) had a significantly higher 5-year disease-free survival rate than patients receiving RT alone (89%versus 75% respectively) (P = 0.039). Multivariate analysis confirmed that treatment modality was the significant factor influencing patient survival (P = 0.027) and the pathological type was not a factor predicting survival.

CONCLUSIONS

Nasopharyngeal adenocarcinoma is a distinct entity in all types of nasopharyngeal carcinoma and EBV serology has limited value in its diagnosis. The combination of surgery and RT should be considered for treatment of early lesions of NPAC.

ZnO/Al2O3 core-shell nanorod arrays: growth, structural characterization, and luminescent properties

We report an aqueous chemical method to fabricate well-aligned ZnO/Al(2)O(3) nanocrystal (NC) core-shell nanorod arrays (NRAs). Structural characterization showed that the shell layers are composed of alpha-Al(2)O(3) nanocrystals. Photoluminescence measurements showed the enhancement of near-band-edge (NBE) emission of ZnO NRAs due to the presence of Al(2)O(3) NC shells. The Al(2)O(3) NC shell layer resulting in the flat-band effect near the ZnO surface leads to a stronger overlap of the wavefunctions of electrons and holes in the ZnO core, further enhancing the NBE emission. This approach should be very useful in designing many other core-shell NRAs for creating varieties of high-efficiency optoelectronic devices.

Electrical and optoelectronic characterization of a ZnO nanowire contacted by focused-ion-beam-deposited Pt

We report on the transport properties of a single ZnO nanowire (NW) measured as a function of the length/square of the radius ratio via the transmission line method (TLM). The specific contact resistance of FIB-Pt contacts to the ZnO NWs is determined to be as low as 1.1 x 10(-5) Omega cm(2). The resistivity of the ZnO NWs is measured to be 2.2 x 10(-2) Omega cm. ZnO NW-based UV photodetectors contacted by FIB-Pt with a photoconductive gain as high as approximately 10(8) have been fabricated and characterized.

Polymer functionalized ZnO nanobelts as oxygen sensors with a significant response enhancement

A plasma-polymerized acrylonitrile (PP-AN)/ZnO nanobelt (NB) nanosensor reveals a better oxygen-sensing response than a bare ZnO NB nanosensor due to the sorption nature of the polymer. With the aid of UV light, significant response enhancements of PP-AN/ZnO NB nanosensors at low temperature have been observed since the effects of oxygen desorption/adsorption in PP-AN on the electron depletion region in the ZnO are significant. The minimum sensitivity at 150 degrees C is 16.6 ppm. This work permits its feasibility in areas where it is impossible to work at higher temperatures since lowering the working temperature of the sensor can avoid the structural deterioration, causing instability in the response.

Aligned Er-doped ZnO nanorod arrays with enhanced 1.54 microm infrared emission

Vertically aligned Er-doped ZnO nanorod arrays with sharp and intense 1.54 microm infrared emission have been fabricated on Si substrates through a well controlled spin-coating and annealing process. The synthesis method is advantageous for synthesizing ZnO nanostructures free from structural defects, capability for large-scale production, minimum equipment requirement and product homogeneity. Er atoms were found to incorporate into ZnO lattice from XRD, ESCA, TEM, STEM/EDS and PL measurements. The single-crystal Er-doped nanorods maintained their high microstructural quality after annealing for 4 hr at 800 degreesC. The intensity of 1.54 microm infrared emission was found to be correlated with the deep level green emission. The enhanced luminescence intensity and best ever narrow wavelength distribution of Er-doped ZnO nanorod arrays at 1.54 microm emission will be conductive to applications in optoelectronic devices and optical communications.

Lateral self-aligned p-type In2O3 nanowire arrays epitaxially grown on Si substrates

Lateral orientated growth of In2O3 nanowire (NW) and nanorod (NR) arrays has been achieved by a vapor transport and condensation method on (001) and (111) surfaces of Si substrates. The single crystalline In2O3 NWs and NRs were grown along [211] in parallel to the Si +/-[110] and lying in the substrate plane. The electrical measurements show that the In2O3 NWs are p-type semiconductor. By N+ doping, the resistivity of the In2O3 NWs has been tuned. The lateral self-aligned In2O3 NW and NR arrays on Si can offer some unique advantages for fabricating parallel nanodevices that can be integrated directly with silicon technology.

Dietary thyroid hormone improves growth and muscle protein accumulation of black-boned chickens

1. The objective of the study was to examine the effect of dietary thyroid hormone on performance and muscle protein accumulation of black-boned chickens. 2. A total of 720 1-d-old birds was housed in 24 pens and assigned to 4 diets containing triiodothyronine (T3) at 0, 0.1, 0.3 or 0.5 mg/kg. 3. The trial was split into starter (0 to 4 weeks) and grower (5 to 8 weeks) phases. At the beginning of the grower phase, each pen was split into two; one subgroup was fed basal diet (T3-) and the other continued with T3-added diet (T3+). 4. Dietary T3 at 0.1 mg/kg improved average daily body weight gain until week 6 but retarded it thereafter. However, T3 at 0.5 mg/kg depressed growth throughout the whole period. During weeks 7 to 8, T3 retarded growth, whereas growth recovered when T3 was withdrawn from the diet. 5. Birds fed the diet containing 0.1 mg/kg during weeks 0 to 4 and those receiving basal diet during weeks 5 to 8 showed the greatest thigh muscle growth, but this growth was depressed when they were fed the 0.5 mg/kg diet during weeks 0 to 8. 6. Serum T3 concentration was increased, while thyroxine (T4) concentration was decreased by dietary T3 treatment at 2 weeks old. At 4 weeks old, T3 and T4 concentrations decreased. At 6 and 8 weeks old, among T3-treated groups the serum T3 concentration of the T3- group was higher than that of the T3+ group. 7. In conclusion, dietary T3 improved weight gain and muscle growth of black-boned chickens before week 6, whereas supplementation depressed growth after 6 weeks. Optimum dietary T3 concentrations showed a carry-over effect on both body weight gain and thigh muscle growth.

Bombardment-induced tunable superlattices in the growth of Au-Ni films

Highly ordered superlattices are typically created through the sequential deposition of two different materials. Here, we report our experimental observation of spontaneous formation of superlattices in coevaporation of Au and Ni under energetic ion bombardment. The superlattice periodicities are on the order of a few nanometers and can be adjusted through the energy and flux of ion beams. Such a self-organization process is a consequence of the bombardment-induced segregation and uphill diffusion within the advancing nanoscale subsurface zone in the film growth. Our observations suggest that ion beams can be employed to make tunable natural superlattices in the deposition of phase-separated systems with strong bombardment-induced segregation.

Effect of dietary oligochitosan supplementation on ileal digestibility of nutrients and performance in broilers

The effect of dietary chitosan oligosaccharides (COS) supplementation on ileal digestibilities of nutrients and performance in broilers was assessed by feeding graded levels (0, 50, 100, 150 mg/kg) of COS. Two thousand four hundred male commercial Avian broilers (1-d-old) were assigned randomly to 5 dietary treatment groups (60 birds per pen with 8 pens per treatment). Diet A was a typical corn- and soybean meal-based diet supplemented with 6 mg/kg of an antibiotic flavomycin (positive control). Diet B was the basal diet without any supplement. Diets C, D, and E were formulated by adding 50, 100, and 150 mg/kg of COS to the basal diet, respectively. On the morning of d 21 and 42, 64 birds (8 per pen with 8 pens per treatment) from the growth trial for each age group were killed by cervical dislocation for determination of the ileal digestibilities of nutrients. Dietary supplementation with COS and antibiotic enhanced (P < 0.05) the ileal digestibilities of DM, Ca, P, CP, and all amino acids (except for alanine in the 21-d-old birds or phenylalanine, glutamate, and glycine for the 42-d-old birds). Feed efficiency was improved (P < 0.05) in response to dietary supplementation of an antibiotic or COS (150 mg/kg for d 1 to 21, and 100 and 150 mg/kg for d 21 to 42). The results demonstrate for the first time to our knowledge that dietary COS supplementation was effective in increasing the ileal digestibilities of nutrients and feed efficiency in broilers. Our findings may explain a beneficial effect of COS on chicken growth performance.

Effects of the silanized mica surface on protein crystallization

A freshly cleaved mica surface silanized by 3-aminopropyl triethoxysilane is flat over a large area, displays a controlled degree of hydrophobicity and contains positive charges. In this paper, mica sheets silanized by this method have been used as crystallization surfaces for lysozyme, trichosanthin and three other proteins of unknown structure. Crystallization experiments have been carried out by the hanging-drop vapour-diffusion technique and the results indicate that the silanized mica surface can ameliorate the protein crystallization process considerably compared with a silanized glass cover slip control. For lysozyme on the silanized mica surface, the induction time required for crystal growth decreases markedly. For trichosanthin, the crystal size is obviously larger and the number of crystals grown is much lower. For the three proteins of unknown structure, the diffraction ability of the crystals is improved considerably.

Dietary methionine requirement of the Chinese egg-laying duck

1. The dietary methionine requirement of egg-laying ducks was assessed by feeding diets supplemented with graded levels of DL-methionine (0, 4, 8, 12, 16 g/kg dietary protein) for 8 weeks. The basal diet contained 175 g protein and 2.6 g methionine per kg feed (or 14.9 g/kg protein) and an estimated ME of 11.5 MJ/kg. 2. A total of 800 Shaoxin laying ducks (420 d old) were randomly divided into 5 groups of 160 each and fed in 4 separate pens. 3. Dietary supplementation of methionine significantly increased egg production and feed conversion efficiency. 4. Dietary methionine requirement for optimum egg production was estimated to be 25.7 g/kg of dietary protein or 4.5 g/kg of the diet or 380 mg/bird-d. 5. Methionine supplementation increased the methionine level in plasma, and the free glutamic acid and aspartic acid concentrations in plasma were quadratically related to dietary methionine levels. Increasing dietary methionine had little effect on egg quality characteristics.

Icosahedral short-range order in amorphous alloys

We have characterized the icosahedral short-range order in amorphous solids using local environment probes. Such topological local order is pronounced even in an amorphous alloy that does not form quasicrystalline phases upon crystallization, as demonstrated by the extended x-ray absorption fine structure and x-ray absorption near-edge structure of a Ni-Ag amorphous alloy analyzed through reverse Monte Carlo simulations.

Homogeneity of a supersaturated solid solution

Extended x-ray absorption fine structures, small-angle x-ray scattering, and atomistic model calculations have been employed to probe the homogeneity of the fcc solution created in Ag-Cu, a classical system demonstrating the extension of solubility across the entire miscibility gap through rapid quenching. Our results reveal that in many cases the supersaturated solutions formed have decomposition features on the scale of 1 nm. Conventional diffraction methods are inadequate in determining the level of supersaturation or the uniformity of such solid solution alloys.

Amorphous structures in the immiscible Ag-Ni system

Vapor quenching in the phase-separating Ag-Ni system creates alloys that appear homogeneously amorphous under conventional probes. However, an atomic-level structural analysis based on extended x-ray absorption fine structures in combination with reverse Monte Carlo and molecular dynamics simulations demonstrates that these new phases are characterized by nonuniform, spinodal-like structures on an extremely fine scale. This heterogeneous nature of the structure is directly responsible for the unexpectedly low heat (and temperature) of crystallization observed in calorimetric measurements.

Altered expression of the suppressors PML and p53 in glioblastoma cells with the antisense-EGF-receptor

Gene amplification and enhanced expression of the epidermal growth factor receptor (EGFR) represent the major molecular genetic alteration in glioblastomas and it may play an essential role in cell growth and in the carcinogenic process. On the other hand, the nuclear suppressor proteins PML and p53 are also known to play critical roles in cancer development and in suppressing cell growth. Here we report that, in glioblastoma cells with defective EGFR function, the expressions of both promyelocytic leukaemia (PML) and p53 were altered. Cells that were transfected with the antisense-cDNA of EGFR were found to have more cells in G1 and fewer cells in S phase. In addition, the transfected cells were found to be non-responsive to EGF-induced cell growth. Interestingly, the expression of the suppressors p53 and PML were found to be significantly increased by immunohistochemical assay in the antisense-EGFR cells. Moreover, the PML expression in many of the cells was converted from the nuclear dot pattern into fine-granulated staining pattern. In contrast, the expressions of other cell cycle regulated genes and proto-oncogene, including the cyclin-dependent kinase 4 (cdk4), retinoblastoma, p16INK4a and p21H-ras, were not altered. These data indicate that there are specific inductions of PML and p53 proteins which may account for the increase in G1 and growth arrest in antisense-EGFR treated cells. It also indicates that the EGF, p53 and PML transduction pathways were linked and they may constitute an integral part of an altered growth regulatory programme. The interactions and cross-talks of these critical molecules may be very important in regulating cell growth, differentiation and cellular response to treatment in glioblastomas.

Anticancer effect of Howiinol A and its mechanism of action

Howiinol A (GHM-10) is a kind of phenylethylene pyrone compounds isolated from Goniothalamus howii. By using the techniques of cell growth curve determination, MTT test, soft agar colony assay and experimental therapy of transplantable tumors in mice, it is found that GHM-10 exerts potent inhibitory effect on cancer cells but its influence on normal cells is relatively slight; the sensitivity of a drug-resistant cell line, KB/VCR 2000, to GHM-10 is similar to its parent cell line KB. Remarkable therapeutic effect can be seen in mice bearing H22 hepatoma and Lewis lung cancer and in mice with ascetic sarcoma 180 when GHM-10 is orally or intraperitoneally administered. The IC50s of L1210 cells treated with GHM-10 for 1 and 24 h are 6.85 and 3.32 micrograms.ml-1 respectively. The ratio of IC50 1 h and IC50 24 h is only 2.06, indicating that the action of GHM-10 is conformed to a cell cycle non-specific cytotoxic agent. By using trypan blue exclusive test and morphological examination, it is demonstrated that the main effect of GHM-10 is to inhibit the cell proliferation. Flow cytometery technique is used to analyze the cell cycle of L1210 cells. The results show that to some extent, GHM-10 blocks the cell cycle transition from G1 phase to S phase. By using [3H] labeled precursor incorporation technique, it is shown that GHM-10 significantly suppresses the biosynthesis of DNA, RNA and protein in L1210 cells, and the DNA synthesis is mostly affected. At 1 h after the cells were treated with GHM-10, these inhibitory effects have already been irreversible, suggesting that GHM-10 may cause structural damage on DNA molecules. However, GHM-10 is unable to intercalate into DNA molecules or to destroy its structure directly. By using single cell gel electrophoresis and alkaline elution technology, it is confirmed that GHM-10 causes DNA molecule damage and single strand breakage in L1210 cells. Further studies show that GHM-10 markedly inhibits DNA dehelix induced by DNA topoisomerase II both inside and outside the cells, indicating that GHM-10 is acting as an inhibitor of DNA topoisomerase II.

[A study on the transmission of plague though seven kinds of fleas in rat type and wild rodent type plague foci in Yunnan]

In order to assess vector position and vector action of seven kinds of fleas in the rat type and wild rodent type plague foci in Yunnan, we studied the indices as: infection rate, rate of feed bacterial emboli, colony transmission vector efficiency, life-span, bloodthirsty to human, body weight, quantity of blood-sucking, rate of dissociation by using animal model and raise film method. The results showed that Xenopsylla cheopis and Neopsylla specialis specialis were the main vectors of two type plague foci. Pulex irritans was an important vector of human plague in Yunnan. This paper reported that Xenopsylla cheopis and Neopsylla special special could twice form bacterial emboli, and with other information about vector efficiency, Index of Pulex irritans, Neopsylla special special, Frontopsylla spadix, Monopsyllus anisus, rate of bloodthirsty to human and life-span of seven kinds of fleas. Reason from quiescence to resuscitate was also deduced and the vector position of Leptopsylla segnis was revised. The vector action of main vector for Ctenophalmus quadratus was negated which proved that Apodemus chevrieri was the main reservoirs in these plague foci.

A study of siliceous pneumoconiosis in a desert area of Sunan County, Gansu Province, China

Three hundred and ninety five residents in a desert area were examined with chest radiographs and 28 cases with siliceous pneumoconiosis were found. The prevalence of siliceous pneumoconiosis was 7.09%, and that over 40 years of age was 21%. The histological findings of lungs from a camel living in that area for 20 years also confirmed to have siliceous pneumoconiosis.

Serotyping and antigenic comparison of some animal rotaviruses isolated in China

Eight strains of rotaviruses isolated from diarrheal animals (4 from calves and 4 from piglets) in China were compared by serotyping with reference animal rotavirus strains (bovine NCDV, porcine OSU and simian SA-11 and human rotavirus Wa strain). Two-way cross neutralization test showed no antigenic difference between all 4 local strains of bovine rotavirus (BRV007, BRV014, HN-7 and BRV6555) and reference NCDV, so they belonged to rotavirus serotype 6 (bovine rotavirus serotype 1 or NCDV-serotype). Meanwhile, the four strains of Chinese porcine rotavirus could be determined into 2 different serotypes. One (Li99) was neutralised to a high titer with the antiserum against reference OSU virus and probably related to OSU (serotype 5 or porcine serotype 1). The other three strains (Lin71, Nan86 and Jiang150) were antigenically obviously different from Li99 and did not react with the antiserum against OSU. They were tentatively considered as porcine rotavirus serotype 2. All the strains of bovine and porcine rotavirus did not cross-neutralise with simian SA-11 and human Wa strain. There was also no antigenic relationship between bovine rotaviruses and porcine rotaviruses.

In-vivo and in-vitro studies on the effects of chronic dexamethasone treatment on cardiovascular responses to sympathetic stimulation

Rats treated with dexamethasone, 1.5 mg/kg s.c. weekly for 3 weeks exhibited significantly greater increases in mean arterial pressure than their controls, following either sympathetic nerve stimulation or noradrenaline administration. The atria from dexamethasone-treated rats showed greater chronotropic activity in response to noradrenaline but not to field stimulation, whereas the force of contraction was significantly less than that of the controls after either field or noradrenaline stimulation. Isolated rat tail artery preparations from dexamethasone-treated rats were found to be twice more sensitive to noradrenaline than the controls. Prazosin antagonised the noradrenaline-induced pressor response to the same extent in control and dexamethasone-treated rats. Dexamethasone treatment did not significantly increase the sensitivity to KCl or the angiotensin-potentiated pressor response to noradrenaline. This study shows that dexamethasone treatment increases postsynaptic sensitivity of the cardiovascular system to noradrenaline in rats.