Enabling Waveguide Optics in Rhombohedral-Stacked Transition Metal Dichalcogenides with Laser-Patterned Grating Couplers

Waveguides play a key role in the implementation of on-chip optical elements and, therefore, lie at the heart of integrated photonics. To add the functionalities of layered materials to existing technologies, dedicated fabrication protocols are required. Here, we build on laser writing to pattern grating structures into bulk noncentrosymmetric transition metal dichalcogenides with grooves as sharp as 250 nm. Using thin flakes of 3R-MoS2 that act as waveguides for near-infrared light, we demonstrate the functionality of the grating couplers with two complementary experiments: first, nano-optical imaging is used to visualize transverse electric and magnetic modes, whose directional outcoupling is captured by finite element simulations. Second, waveguide second-harmonic generation is demonstrated by grating-coupling femtosecond pulses into the slabs in which the radiation partially undergoes frequency doubling throughout the propagation. Our work provides a straightforward strategy for laser patterning of van der Waals crystals, demonstrates the feasibility of compact frequency converters, and examines the tuning knobs that enable optimized coupling into layered waveguides.

Experimental study of modified Tavis-Cummings model with directly-coupled superconducting artificial atoms

The Tavis-Cummings model is intensively investigated in quantum optics and has important applications in generation of multi-atom entanglement. Here, we employ a superconducting circuit quantum electrodynamic system to study a modified Tavis-Cummings model with directly-coupled atoms. In our device, three superconducting artificial atoms are arranged in a chain with direct coupling through fixed capacitors and strongly coupled to a transmission line resonator. By performing transmission spectrum measurements, we observe different anticrossing structures when one or two qubits are resonantly coupled to the resonator. In the case of the two-qubit Tavis-Cummings model without qubit-qubit interaction, we observe two dips at the resonance point of the anticrossing. The splitting of these dips is determined by Δ λ=2g12+g32, where g1 and g3 are the coupling strengths between Qubit 1 and the resonator, and Qubit 3 and the resonator, respectively. The direct coupling J12 between the two qubits results in three dressed states in the two-qubit Tavis-Cummings model at the frequency resonance point, leading to three dips in the transmission spectrum. In this case, the distance between the two farthest and asymmetrical dips, arising from the energy level splitting, is larger than in the previous case. The frequency interval between these two dips is determined by the difference in eigenvalues (Δ λ=ε 1+-ε 1-), obtained through numerical calculations. What we believe as novel and intriguing experimental results may potentially advance quantum optics experiments, providing valuable insights for future research.

[Analysis of work-related musculoskeletal disorders among automobile manufacturing logistics workers in Guangzhou]

Objective: To investigate the occurrence of work-related musculoskeletal disorders (WMSDs) in logistics workers of automobile manufacturing enterprises in Guangzhou, and explore their potential categories and influencing factors, so as to provide basis for the prevention and control of WMSDs in logistics workers of automobile manufacturing enterprises. Methods: From April to May 2020, a convenient sampling method was adopted to select 1442 logistics workers in 2 automobile manufacturing enterprises in Guangzhou as the research objects. The incidence of WMSDs among them was investigated by using the Nordic Musculoskeletal Disorders Questionnaire, and the incidence pattern of WMSDs among the subjects was analyzed by the method of potential category analysis. Chi-square test and multiple logistic regression model were used to analyze the influencing factors of the disease. Results: The total prevalence of WMSDs was 42.9% (619/1442). The three parts with high prevalence of WMSDs were neck (23.5%, 339/1442), shoulder (21.3%, 307/1442) and lower back (19.1%, 275/1442). 69.0% (427/619) of the patients showed simultaneous disease in two or more sites. The subjects were divided into four latent groups by the analysis of latent categories: the group with multiple body parts (4.51%), the group with very low or no disease (70.39%), the group with shoulder and neck and upper back (11.37%), and the group with limbs and lower back (13.73%). Multivariate logistic regression showed that compared with the "very low or no disease group", the risk factors of multiple body parts of automotive logistics workers suffering from WMSDs mainly included: Working posture uncomfortable (OR=3.10, 95%CI: 1.44~6.70, P=0.004), often bend and turn (OR=2.36, 95%CI: 1.05~5.29, P=0.037), bend your knees homework for a long time (OR=2.29, 95%CI: 1.17~4.47, P=0.015) ; Working posture uncomfortable (OR=2.26, 95%CI: 1.51~3.38, P<0.001), bending the neck (OR=1.68, 95%CI: 1.03~2.74, P=0.036), neck minister time keep the same position (OR=1.81, 95%CI: 1.22~2.67, P= 0.003) It is a risk factor for shoulder, neck and upper back WMSDs; Risk factors for limb-lower back WMSDs include: Length > 10 years (OR=2.16, 95%CI: 1.24~3.78, P<0.001), the working position uncomfortable (OR=2.38, 95%CI: 1.63~3.48, P<0.001), bending the neck (OR=1.66, 95%CI: 1.03~2.68, P=0.039) . Conclusion: The prevalence rate of WMSDs among logistics workers in automobile manufacturing enterprises is high, which has obvious characteristics of classification and comorbis, and is closely related to individual characteristics such as sufficient rest time and working posture of workers.

[Research and reflection on the diversified method system of multi-stages and multi-scenarios surveillance and early warning of infectious diseases]

With the outbreak of infectious diseases, more and more attention has been paid to surveillance and early warning work. Timely and accurate monitoring data is the basis of infectious diseases prevention and control. Effective early warning methods for infectious diseases can improve the timeliness and sensitivity of early warning work. This paper briefly introduces the intelligent early warning model of infectious diseases, summarizes the emerging surveillance and early warning methods of infectious diseases, and seeks the possibility of diversified surveillance and early warning in different epidemic stages and different outbreak scenarios of infectious diseases. This paper puts forward the idea of constructing a diversified method system of infectious diseases surveillance and early warning based on multi-stages and multi-scenarios and discusses the future development trend of infectious diseases surveillance and early warning, in order to provide reference for improving the construction level of infectious diseases surveillance and early warning system in China.

[Thinking about development of multi-channel surveillance and multi-dimensional early warning system of emerging respiratory communicable diseases]

The world has paid a heavy price for the pandemic of the emerging respiratory communicable disease, so more concern about communicable disease surveillance and early warning has been aroused. This paper briefly reviews the establishment of the surveillance and early warning system of respiratory communicable diseases in China, discusses its future development and introduces the novel surveillance methods and early warning models for the purpose of establishment of a multi-channel surveillance and multi-dimensional early warning system of communicable diseases in the future and the improvement of the prevention and control of emerging respiratory communicable diseases in China.

[The status of projects funded in division of preventive medicine in National Natural Science Foundation of China from the financial year 2007-2021]

It is of great significance to analyze the configuration of programs funded by the National Natural Science Foundation of China using funding data in the field of preventive medicine from 2007 to 2021. The analysis mainly focused on the funding status of the program, funding amount, funded institutions and personnel. A total of 5 349 programs in the discipline of preventive medicine were funded over the last 15 years. The funding amount in this discipline accounted for a relatively low proportion in the total funding amount of the Department of Medical Sciences and this proportion also showed a decreasing trend. Non-infectious disease epidemiology, human nutrition, and health toxicology were the top three subdisciplines of all funded programs in preventive medicine. The proportion of programs led by young scholars was gradually rising over the years, and young scholars were playing an increasingly influential role in scientific research. The funding status among each subdiscipline and institution also varied. The results of this study reflected the thriving of preventive medicine. Meanwhile, some problems and dilemmas were also revealed in its current development. Hopefully, this study could provide valuable information for institutions and preventive medicine researchers to apply for National Natural Science Foundation, and promote the long-term development of preventive medicine in the future.

[Advance on theoretical epidemiology models research of prevention and control of COVID-19]

COVID-19 has brought a significant impact to the global health system, and also opportunities and challenges to epidemiological researches. Theoretical epidemiological models can simulate the process of epidemic in scenarios under different conditions. Therefore, modeling researches can analyze the epidemical trend of COVID-19, predict epidemical risks, and evaluate effects of different control measures and vaccine policies. Theoretical epidemiological modeling researches provide scientific advice for the prevention and control of infectious diseases, and play a crucial role in containing COVID-19 over the past year. In this study, we review the theoretical epidemiological modeling researches on COVID-19 and summarize the role of theoretical epidemiological models in the prevention and control of COVID-19, in order to provide reference for the combination of mathematical modeling and epidemic control.

[Analysis on dynamical mechanism of multi outbreaks of COVID-19]

Objective: In the context of COVID-19 pandemic, the epidemic severities, non-pharmaceutical intervention intensities, individual behavior patterns and vaccination coverage vary with countries in the world. China has experienced a long period without indigenous cases, unfortunately, multi local outbreaks caused by imported cases and other factors have been reported, posing great challenges to COVID-19 prevention and control in China. Thus it is necessary to explore the mechanisms of the re-emerged COVID-19 epidemics and their differences. Methods: Based on susceptible exposed infectious recovered (SEIR) epidemic dynamics model, we developed a set of novel evolution equations which can describe the dynamic processes of integrated influence of interventions, vaccination coverage and individual behavior changes on the re-emergency of COVID-19 epidemic. We developed methods to calculate the optimal intervention intensity and vaccination rate at which the size of susceptible population can be reduced to less than threshold for the re-emergency of COVID-19 epidemic. Results: If strong interventions or super interventions are lifted too early, even a small cause can lead to the re-emergence of COVID-19 epidemic at different degrees. Moreover, the stronger the early control measures lifted are, the more severe the epidemic is. The individual behavior changes for the susceptibility to the epidemic and the enhancement or lifting of prevention and control measures are key factors to influence the incidence the multi outbreaks of COVID-19. The optimist early intervention measures and timely optimization of vaccination can not only prevent the re-emergency of COVID-19 epidemic, but also effectively lower the peak of the first wave of the epidemic and delay its arrival. Conclusion: The study revealed that factors for the re-emergence of COVID-19 epidemics included the intensity and lifting of interventions, the change of individual behavior to the response of the epidemic, external incentives and the transmissibility of COVID-19.

[Construction of urban scale-free network model and its epidemiological significance in the prevention and control of COVID-19]

COVID-19 is a public health emergency currently. In this study, a scale-free network model is established based on the Spring Migration data in 2020.The cities is clustered into three different modules. The epidemic of the cities in the black module was the most serious, followed by the red and the cyan. The black module contains 9 cities in Zhejiang province and 8 cities in Guangdong province, most of them located in the southeast coastal economic belt. These cities should be the key cities for epidemic prevention and control.

[Progress of research regarding the influenza early warning system, based on "Big Data"]

Shortcomings have been inherited in the traditional influenza early warning system, often expressed through the scope, accuracy on prediction and real-time performance of the monitor related programs. With the new round of scientific and technological revolution and the increasingly maturity of modern information system, related technology on influenza early warning has become the focus of research in this field, based on big data analysis technology. Using the traditional influenza surveillance and early warning system as reference, this paper summarizes the progress of influenza early warning research, based on the Internet, influencing factors, time and space trends, and risk assessment etc., to summarize the trends on the advantages, shortcomings and future development of big data, used in the early warning system on influenza.

[Research progress on the association between HIV antiretroviral therapy and the outbreak]

Since the implementation of antiretroviral therapy (ART), it has achieved remarkable results in the field of HIV/AIDS treatment. However, when the treatment is applied to the population-level, the actual impact of ART on the HIV epidemic becomes a hot topic in the field. This paper will summarize the research on ART and HIV epidemic in recent years, and discuss the impact of ART on the trend of HIV epidemic, so as to provide scientific support and suggestions for the role of treatment is prevention.

Topologically Protected Quantum Coherence in a Superatom

Exploring the properties and applications of topological quantum states is essential to better understand topological matter. Here, we theoretically study a quasi-one-dimensional topological atom array. In the low-energy regime, the atom array is equivalent to a topological superatom. Driving the superatom in a cavity, we study the interaction between light and topological quantum states. We find that the edge states exhibit topology-protected quantum coherence, which can be characterized from the photon transmission. This quantum coherence helps us to find a superradiance-subradiance transition, and we also study its finite-size scaling behavior. The superradiance-subradiance transition also exists in symmetry-breaking systems. More importantly, it is shown that the quantum coherence of the subradiant edge state is robust to random noises, allowing the superatom to work as a topologically protected quantum memory. We suggest a relevant experiment with three-dimensional circuit QED. Our study may have applications in quantum computation and quantum optics based on topological edge states.

Clinical and pathologic predictors of central lymph node metastasis in papillary thyroid microcarcinoma: a retrospective cohort study

OBJECTIVE

To identify the clinical and pathological predictors of central lymph node metastasis (CLNM) in patients with clinically lymph node-negative papillary thyroid microcarcinoma (PTMC).

MATERIALS AND METHODS

Data pertaining to 541 clinically lymph node-negative PTMC patients who underwent thyroid surgery at the Shanghai General Hospital between January 2010 and December 2013 were retrospectively analyzed. According to histopathological evidence of central lymph node involvement, patients were divided into central lymph node metastasis (CLNM)-positive and CLNM-negative groups; risk factors for CLNM were identified statistically.

RESULTS

LNM was found in 148 (27.4%) patients. Gender (P = 0.002), age (P < 0.001), tumor size (P < 0.001), multifocality (P < 0.001), and extrathyroidal extension (P < 0.001) were significantly different between CLNM-positive and CLNM-negative groups. On multivariate analyses, male sex (odds ratio [OR] = 2.656), age <45 years (OR = 4.184), tumor size >0.575 cm (OR = 2.105), gross extrathyroidal extension (OR = 14.605) and multifocality (OR = 2.084) were independent risk factors for CLNM. Among patients who did not have any of these five risk factors, only 3.9% were found to have CLNM.

CONCLUSIONS

A relatively high prevalence of CLNM was observed in patients with clinically lymph node-negative PTMC. CLNM was associated with male sex, younger age, larger tumor size, extrathyroidal extension and multifocal PTMC.

[HCV infection status and risk factors in remunerated blood donors in Jiangsu province]

OBJECTIVE

To investigate the infection status of HCV in remunerated blood donors and risk factors in Jiangsu province.

METHODS

A Cross-sectional study was conducted among people aged >50 years. Questionnaires were used to collect the information about their demographic characteristics and risk behaviors, and venous blood samples were collected from them to detect HCV anti-body, HCV-RNA and other biochemical indicators. EpiData and Stata were used for data entry and statistical analysis.

RESULTS

The overall HCV sero-prevalence rates were 22.55% and 61.05% among remunerated blood donors. Data from multiple stepwise regression analysis showed that alanine aminotransferase(ALT)(adjusted OR=1.38, 95%CI: 1.18-1.62)and aspartate aminotransferase(AST)(adjusted OR=1.30, 95%CI: 1.10-1.54)were associated with the outcomes of HCV infection, and fasting plasma glucose(adjusted OR=1.17, 95%CI: 1.01-1.35)were associated with HCV RNA viral loads.

CONCLUSION

The prevalence of HCV infection in remunerated blood donors was high, clinical ALT, AST and fasting plasma glucose levels were associated with the risk for HCV infection and HCV RNA viral load.

Correlated Emission Lasing in Harmonic Oscillators Coupled via a Single Three-Level Artificial Atom

A single superconducting artificial atom can be used for coupling electromagnetic fields up to the single-photon level due to an easily achieved strong coupling regime. Bringing a pair of harmonic oscillators into resonance with the transitions of a three-level atom converts atomic spontaneous processes into correlated emission dynamics. We present the experimental demonstration of two-mode correlated emission lasing in harmonic oscillators coupled via a fully controllable three-level superconducting quantum system (artificial atom). The correlation of emissions with two different colors reveals itself as equally narrowed linewidths and quenching of their mutual phase diffusion. The mutual linewidth is more than 4 orders of magnitude narrower than the Schawlow-Townes limit. The interference between the different color lasing fields demonstrates that the two-mode fields are strongly correlated.

Verification and evaluation of grain QTLs using RILs from TD70 x Kasalath in rice

Grain size is an important trait that directly influences the yield of rice. Validation and evaluation of grain genes is important in rice genetic studies and for breeding. In a population of 240 recombinant inbred lines (RILs) derived from a cross between an extra-large grain japonica variety TD70 and a small grain indica variety Kasalath, we mapped 19 QTLs controlling grain traits. These QTLs included six cloned grain genes, namely, GW2, GS3, qSW5, qGL3, GS5, and GW8. All of the alleles with the optimal effects on grain size came from TD70, the variety with extra-large grains. To verify these gene loci, we cloned and sequenced GW2, GS3, GW5 (qSW5), qGL3, GS5, GW8, and TGW6 in TD70 and Kasalath, and found several functional polymorphisms in the sequences of the genes. New functional markers for the cloned genes were designed to identify parents and RILs. The contributions of these polymorphisms to the improvement in rice grain size traits were evaluated. Our results indicate that at least six functional polymorphisms have additive effects on grain shape and that one non-functional polymorphism in TGW6 affects grain shape in TD70. The newly designed markers will be useful in further studies to identify functional grain genes. Our findings provide insight into the control of grain size in rice, and they will be of value for improving rice grain yield.

The beneficial effect of metformin on β-cell function in non-obese Chinese subjects with newly diagnosed type 2 diabetes

AIM

Studies with metformin suggest a favourable change in β-cell function over sulphonylureas in the early course of obese type 2 diabetes mellitus (T2DM), but it remains unclear whether a similar effect is observed in non-obese individuals. Here we investigated the effects of metformin or glipizide gastrointestinal therapeutics system extended-release formulation (GITS) on β-cell function in non-obese patients with newly diagnosed T2DM.

METHODS

A total of 160 newly diagnosed patients with fasting glucose 7.0-13.0 mmol/L and body mass index <30 kg/m(2) from five centres in China were randomized to metformin or glipizide GITS for 24 weeks. Early insulin secretion [the ratio of area under the curve (AUC) of insulin to glucose during 0-30 min (InsAUC30 /GluAUC30 )] and insulin sensitivity [Matsuda index (ISIM )] were assessed during the standard meal tolerance test before and after therapy. Plasma glucagon-like peptide-1(GLP-1) and glucagon levels were also measured.

RESULTS

Metformin improved InsAUC30 /GluAUC30 significantly (from 8.1 ± 0.6 pmol/mmol to 10.7 ± 0.7 pmol/mmol, p < 0.05), comparable to results with glipizide GITS. In the metformin-treated lean (body mass index < 25 kg/m(2) ) subgroup, the increase in ISIM was not significant, but the improvement in InsAUC30 /GluAUC30 was of great magnitude. Increased GLP-1 responses during meal tolerance test and decreased fasting glucagon level were observed after metformin treatment. Correlation analysis showed that the improvement of InsAUC30 /GluAUC30 was associated with the changes in HbA1c (r = -0.374, p = 0.000), ISIM (r = 0.356, p = 0.001), and ΔGLP-10-30 (r = 0.225, p = 0.02).

CONCLUSIONS

Metformin improved β-cell function in non-obese subjects with newly diagnosed T2DM, which was partly independent of the change in insulin sensitivity in these subjects. This study provides evidence-based data to support metformin use in non-obese patients with T2DM as the first-line agent, which can improve both insulin sensitivity and β-cell function.

Characterization and primary functional analysis of phenylalanine ammonia-lyase gene from Phyllostachys edulis

Phenylalanine ammonia-lyase (PAL) catalyzes the first reaction in phenylpropanoid pathway leading to the production of phenolic compounds with a wide range of biological functions. The cDNA encoding PAL was isolated from Phyllostachys edulis by reverse transcription-polymerase chain reaction (RT-PCR) and by 5' and 3' rapid amplification of cDNA ends, and was designated as PePAL. The full length of PePAL was 2,503 bp which contained an open reading frame (ORF) encoding a peptide of 701 amino acids, with a theoretic isoelectric point of 6.49 and a calculated molecular mass of 75.7 kDa. PePAL was heterologously expressed in Escherichia coli and the recombinant proteins exhibited both PAL and tyrosine ammonia-lyase (TAL) activities. The optimum temperature and pH of the recombinant PePAL were 50 °C and 8.5-9.0, respectively. The K (m) and V (max) values for L-phenylalanine was calculated as 422 μM and 45.9 nM s⁻¹, while for L-tyrosine were 78 μM and 7.09 nM s⁻¹, respectively. Tissue-specific expression assay showed that PePAL expressed highest in stem and sheath, followed by leaf, and lowest in root. Though the accumulation of PePAL proteins was observed in all these four organs by Western blotting, the highest was detected in leaf. Immunohistochemistry study showed that PePAL was localized primarily in vascular bundles and part of sclerenchyma cells of leaf, sheath and root. These results suggested that PePAL had similar expression pattern and biochemical properties with PALs in other plants, which laid the basis for molecular engineering to improve the quality of bamboo products.

KEY MESSAGE

PePAL was a protein with bifunctional enzyme activities of PAL and TAL as shown in vitro assays, and localized primarily in bamboo vascular bundles.

Development of a low-cost magnetic microfluidic chip for circulating tumour cell capture

The authors have developed a novel fabrication process for a selective micro-magnetic activated cell sorting (MACS) chip based on ferromagnetic material encapsulated micropillars (FMEMs), which is technically simple and low cost. The FMEM produces a high field gradient to magnetically attract, capture and hold cells on its interface. System test simulations were carried out to predict the efficacy of target capture and verify that the actual magnetic particles behaviour agreed well with model predictions. To determine the ability of the novel microMACS chip to capture circulating tumour cells (CTCs), SW620 human colon cancer cells were used in an in vitro flow model system and were able to be captured with the efficiency of 72.8%. The obvious accumulation of CTCs at a certain location on the chip suggested shear stress events at the pillar boundary may influence efficacy, and should be considered in further optimisation efforts.

Generation and analysis of expressed sequence tags from a normalized cDNA library of young leaf from Ma bamboo (Dendrocalamus latiflorus Munro)

Ma bamboo (Dendrocalamus latiflorus Munro) belongs to Dendrocalamus genus, Bambusease tribe, Bambusoideae subfamily, Poaceae family. It is a representative species of clumping bamboo, and a principal commercial species for various construction purposes using mature culms and for human consumption using young shoots. A normalized cDNA library was constructed from young leaves of Ma bamboo and 9,574 high-quality ESTs were generated, from which 5,317 unigenes including 1,502 contigs and 3,815 singletons were assembled. The unigenes were assigned into different gene ontology (GO) categories and summarized into 13 broad biologically functional groups according to similar functional characteristics or cellular roles by BLAST search against public databases. Eight hundred and ninety-one unigenes were assigned by KO identifiers and mapped to six KEGG biochemical pathways. The transcripts involved in biosynthesis of secondary metabolites such as cytochrome 450, flavonol synthase/flavanone 3-hydroxylase, and dihydroflavonol-4-reductase were well represented by 14 unigenes in the unigene set. The candidate genes involved in phytohormone metabolism, signal transduction and encoding cell wall-associated receptor kinases were also identified. Sixty-seven unigenes related to plant resistance (R) genes, including RPP genes, RGAs and RDL/RF genes, were discovered. These results will provide genome-wide knowledge about the molecular physiology of Ma bamboo young leaves and tools for advanced studies of molecular mechanism underlying leaf growth and development.

Quantum phase diffusion in a small underdamped Josephson junction

Quantum phase diffusion in a small underdamped Nb/AlO(x)/Nb junction (∼0.4 μm(2)) is demonstrated in a wide temperature range of 25-140 mK where macroscopic quantum tunneling (MQT) is the dominant escape mechanism. We propose a two-step transition model to describe the switching process in which the escape rate out of the potential well and the transition rate from phase diffusion to the running state are considered. The transition rate extracted from the experimental switching current distribution follows the predicted Arrhenius law in the thermal regime but is greatly enhanced when MQT becomes dominant.

Inhibition of matrix metalloproteinase-9 attenuates acute small-for-size liver graft injury in rats

Ischemia/reperfusion (I/R) and portal hypertension have been implicated in small-for-size liver graft dysfunction. Matrix metalloproteinases-2 and -9 (MMP-2/9) are critically proposed to involve in hepatic I/R injury and activated by hemodynamic force. We hypothesized that MMP-2/9 overexpression played a crucial role in acute graft injury following small-for-size liver transplantation (LT). Rats were randomly assigned into four groups: 75% partial hepatectomy (PH); 100% LT; 25% LT and 25% LT treated with CTT peptide (MMP-2/9 inhibitor). ELISA, real-time PCR, gelatin zymography and immunohistochemistry were used to determine the expression pattern of MMP-2/9 in liver tissue. MMP-9 expression was significantly increased 6 h after reperfusion and reached a peak 12 h in the 25% LT group, whereas MMP-2 was expressed in all groups invariably. Compared with the 25% LT group, rats from CTT-treated group exhibited markedly decreased alanine aminotransferase and total bilirubin values, downregulated proinflammatory cytokines, attenuated malondialdehyde (MDA) and myeloperoxidase (MPO) activities, and improved liver histology. Likewise, MMP-9 inhibition significantly reduced number of TUNEL-positive cells and caspase-3 activity, along with decreased protein levels of Fas and Fas-L. Specifically, rat survival was also improved in the CTT-treated group. These results support critical function of MMP-9 involved in acute small-for-size livergraft injury.

Implementation of adiabatic geometric gates with superconducting phase qubits

We present an adiabatic geometric quantum computation strategy based on the non-degenerate energy eigenstates in (but not limited to) superconducting phase qubit systems. The fidelity of the designed quantum gate was evaluated in the presence of simulated thermal fluctuations in a superconducting phase qubits circuit and was found to be quite robust against random errors. In addition, it was elucidated that the Berry phase in the designed adiabatic evolution may be detected directly via the quantum state tomography developed for superconducting qubits. We also analyze the effects of control parameter fluctuations on the experimental detection of the Berry phase.

Identification of dauricine and its metabolites in rat urine by liquid chromatography–tandem mass spectrometry

A rapid, sensitive and specific liquid chromatographic-electrospray ionization (ESI) tandem ion trap mass spectrometric method has been developed for identification of dauricine and its metabolites in rat urine. Six healthy rats were administrated a single dose (100 mg/kg) of dauricine by oral gavage. The urine were sampled from 0 to 24 h and purified by using a C18 solid-phase extraction (SPE) cartridge, then the purified urine samples were separated on a reversed-phase C18 column using methanol/2 mmol/L ammonium acetate (70:30, v/v, adjusted to pH 3.5 with formic acid) as mobile phase and detected by an on-line MS detector. Identification and structural elucidation of the metabolites were performed by comparing their changes in molecular mass (Deltam) and full scan MS(n) spectra with those of the parent drug. At least eight metabolites (such as N-demethyl, dehydrogenate, demethoxyl, hydroxyl, glucuronide conjugated and sulfate conjugated metabolites) and the parent drug were found in rat urine.

Effect of oxygen content on the transport properties of LaTiO(3+β/2) thin films

The structural and transport properties of LaTiO(3+β/2) epitaxial thin films, grown at different oxygen pressures ranging from 6.6 × 10(-4) to 5 Pa, have been investigated. X-ray diffraction peaks of the films shift to lower angles with increasing oxygen pressure, indicative of a variation of the corresponding lattice spacing. All the films show T(2) dependence of resistivity over a large temperature range of ∼200 K, suggesting a band-filling-induced metallic Fermi-liquid behaviour. Upturns in resistivity have been revealed at low temperatures, which could be ascribed to the Anderson-localization effect caused by the cation vacancies. Furthermore, for the thin films grown at high oxygen pressures of 0.5 and 5 Pa, the dependence of resistivity on temperature shows a maximum at high temperatures. The maximum seems to support the argument that transition between t-orbital ordering and disordering plays an important role in dominating transport properties at high temperatures. Carrier density deduced from Hall coefficient increases with the decrease of oxygen content, and shows strong temperature dependence. From the experimental data, it can be asserted that in the LaTiO(3+β/2) thin films, besides the band filling effect, localization or disorder caused by La and Ti vacancy effects controls the unique transport properties.

Spectroscopic and theoretical studies on copper(II) complex of maleinitriledithiolate and 1,10-phenanthroline

A complete vibrational spectra analysis of the title complex is performed in this paper. The molecular geometry, binding, electron structure and spectroscopic properties for the title complex are studied in detail by PM3 or ZINDO/S method. It has been found that this complex has a planar structure belonging to the symmetry point group C2v and its ground state is the spin doublet state. By comparison with the observed results, it can be concluded that PM3 methods are reliable to calculate the vibrational spectra of this molecule. It is worth noting that the scientific method of assigning vibrational spectra for a complicated molecule containing metal is established herein for the first time by giving main fixed points and pivotal vibrational units. Besides the regular symbols, the new defined symbols eta and M play an important role in describing the vibrational modes accurately and vividly.

Reactions of tetrakis(dimethylamide)-titanium, -zirconium and -hafnium with silanes: synthesis of unusual amide hydride complexes and mechanistic studies of titanium-silicon-nitride (Ti-Si-N) formation

M(NMe(2))(4) (M = Ti, Zr, Hf) were found to react with H(2)SiR'Ph (R' = H, Me, Ph) to yield H(2), aminosilanes, and black solids. Unusual amide hydride complexes [(Me(2)N)(3)M(mu-H)(mu-NMe(2))(2)](2)M (M = Zr, 1; Hf, 2) were observed to be intermediates and characterized by single-crystal X-ray diffraction. [(Me(2)N)(3)M(mu-D)(mu-NMe(2))(2)](2)M (1-d(2), 2-d(2)) were prepared through reactions of M(NMe(2))(4) with D(2)SiPh(2). Reactions of (Me(2)N)(3)ZrSi(SiMe(3))(3) (5) with H(2)SiR'Ph were found to give aminosilanes and (Me(2)N)(2)Zr(H)Si(SiMe(3))(3) (6). These reactions are reversible through unusual equilibria such as (Me(2)N)(3)ZrSi(SiMe(3))(3) (5) + H(2)SiPh(2) right arrow over left arrow (Me(2)N)(2)Zr(H)Si(SiMe(3))(3) (6) + HSi(NMe(2))Ph(2). The deuteride ligand in (Me(2)N)(2)Zr(D)Si(SiMe(3))(3) (6-d(1)) undergoes H-D exchange with H(2)SiR'Ph (R' = Me, H) to give 6 and HDSiR'Ph. The reaction of Ti(NMe(2))(4) with SiH(4) in chemical vapor deposition at 450 degrees C yielded thin Ti-Si-N ternary films containing TiN and Si(3)N(4). Ti(NMe(2))(4) reacts with SiH(4) at 23 degrees C to give H(2), HSi(NMe(2))(3), and a black solid. HNMe(2) was not detected in this reaction. The reaction mixture, upon heating, gave TiN and Si(3)N(4) powders. Analyses and reactivities of the black solid revealed that it contained -H and unreacted -NMe(2) ligands but no silicon-containing ligand. Ab initio quantum chemical calculations of the reactions of Ti(NR(2))(4) (R = Me, H) with SiH(4) indicated that the formation of aminosilanes and HTi(NR(2))(3) was favored. These calculations also showed that HTi(NH(2))(3) (3b) reacted with SiH(4) or H(3)Si-NH(2) in the following step to give H(2)Ti(NH(2))(2) (4b) and aminosilanes. The results in the current studies indicated that the role of SiH(4) in its reaction with Ti(NMe(2))(4) was mainly to remove amide ligands as HSi(NMe(2))(3). The removal of amide ligands is incomplete, and the reaction thus yielded "=Ti(H)(NMe(2))" as the black solid. Subsequent heating of the black solid and HSi(NMe(2))(3) may then yield TiN and Si(3)N(4), respectively, as the Ti-Si-N materials.

Stereoselective synthesis of substituted gamma-butyrolactones by the [3+2] annulation of allylic silanes with chlorosulfonyl isocyanate: enantioselective total synthesis of (+)-blastmycine

[structure: see text]. A stereoselective synthesis of gamma-butyrolactones by the [3 + 2] annulation of allylic silanes with N-chlorosulfonyl isocyanate (CSI) was developed. An enantioselective total synthesis of (+)-blastmycinone was accomplished using this annulation as the key step.

[Studies on response characteristics of Cl, Br, I of microwave plasma torch atomic emission detector for gas chromatography]

The present paper deals with a microwave plasma torch atomic emission detector for gas chromatography. Argon is used as support gas, carrier gas and make-up gas. The effect of oxygen scavenger gas on the detection performance for chlorine, bromine and iodine is discussed. Detection limits, dynamic ranges, relative standard deviations and response characteristics of GC-MPT-AED for chlorine, bromine and iodine in organic compounds were studied. The results are favorable in comparing with GC-ICP-AED.

1,25-Dihydroxyvitamin D3 increases nuclear vitamin D3 receptors by blocking ubiquitin/proteasome-mediated degradation in human skin

1,25-Dihydroxyvitamin D3 (D3) exerts its effects by binding to and activating nuclear vitamin D3 receptors (VDRs) that regulate transcription of target genes. We have investigated regulation of VDR levels in human skin in vivo and in cultured human keratinocytes. Quantitative ligand-binding analysis revealed that human skin expressed approximately 220 VDRs per cell, which bound D3 with high affinity [(dissociation constant (Kd) = 0.22 nM]. In human skin nuclear extracts, VDR exclusively bound to DNA containing vitamin D3 response elements as heterodimers with retinoid X receptors. Topical application of D3 to human skin elevated VDR protein levels 2-fold, as measured by both ligand-binding and DNA-binding assays. In contrast, the D3 analog calcipotriene had no effect on VDR levels. Topical D3 had no effect on VDR mRNA, indicating that D3 either stimulated synthesis and/or inhibited degradation of VDRs. To investigate this latter possibility, recombinant VDRs were incubated with skin lysates in the presence or absence of D3. The presence of D3 substantially protected VDRs against degradation by human skin lysates. VDR degradation was inhibited by proteasome inhibitors, but not lysosome or serine protease inhibitors. In cultured keratinocytes, D3 or proteasome inhibitors increased VDR protein without affecting VDR mRNA levels. In cells, VDR was ubiquitinated and this ubiquitination was inhibited by D3. Proteasome inhibitors in combination with D3 enhanced VDR-mediated gene expression, as measured by induction of vitamin D3 24-hydroxylase mRNA in cultured keratinocytes. Taken together, our findings indicate that low VDR levels are maintained, in part, through ubiquitin/proteasome-mediated degradation and that low VDR levels limit D3 signaling. D3 exerts dual positive influences on its nuclear receptor, simultaneously stimulating VDR transactivation activity and retarding VDR degradation.

Solid phase synthesis and NMR conformational studies on cyclic decapeptide template molecule

Selectively addressable topological templates represent a key feature in the de novo design of proteins using the TASP concept (Template Assembled Synthetic Proteins). The regioselectively addressable (orthogonally protected) lysine-containing cyclic templates are especially interesting for combinatorial chemistry. We report the synthesis and structural analysis of a series of cyclic and bicyclic decapeptide templates (model of TASP molecules). The peptides were synthesized via solid phase synthesis and followed by solution cyclization. The conformation of the peptides was studied by proton nmr spectroscopy in dimethylsulfoxide and in trifluoroethanol/water. The structure of the peptide template was calculated with the program DIANA and followed by simulated annealing from the nmr experimental constraints. The peptides adopts a fold comprising two beta-strands and two type II beta-turns predicted for conformationally well-defined templates. The design of such a restained cyclic decapeptide template will be discussed along with Regioselectively Addressable Functionalized Template (RAFT) molecular recognition and template for combinatorial synthesis.

Identification of heparin-binding EGF-like growth factor as a target in intercellular regulation of epidermal basal cell growth by suprabasal retinoic acid receptors

The role of retinoic acid receptors (RARs) in intercellular regulation of cell growth was assessed by targeting a dominant-negative RARalpha mutant (dnRARalpha) to differentiated suprabasal cells of mouse epidermis. dnRARalpha lacks transcriptional activation but not DNA-binding and receptor dimerization functions. Analysis of transgenic mice revealed that dnRARalpha dose-dependently impaired induction of basal cell proliferation and epidermal hyperplasia by all-trans RA (tRA). dnRARalpha formed heterodimers with endogenous retinoid X receptor-alpha (RXRalpha) over RA response elements in competition with remaining endogenous RARgamma-RXRalpha heterodimers, and dose-dependently impaired retinoid-dependent gene transcription. To identify genes regulated by retinoid receptors and involved in cell growth control, we analyzed the retinoid effects on expression of the epidermal growth factor (EGF) receptor, EGF, transforming growth factor-alpha, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin genes. In normal epidermis, tRA rapidly and selectively induced expression of HB-EGF but not the others. This induction occurred exclusively in suprabasal cells. In transgenic epidermis, dnRARalpha dose-dependently inhibited tRA induction of suprabasal HB-EGF and subsequent basal cell hyperproliferation. Together, our observations suggest that retinoid receptor heterodimers located in differentiated suprabasal cells mediate retinoid induction of HB-EGF, which in turn stimulates basal cell growth via intercellular signaling. These events may underlie retinoid action in epidermal regeneration during wound healing.

Suprabasal expression of a dominant-negative RXR alpha mutant in transgenic mouse epidermis impairs regulation of gene transcription and basal keratinocyte proliferation by RAR-selective retinoids

To determine whether 9-cis retinoic acid receptors (RXRs) regulate the biological activity of all-trans retinoic acid (tRA) and its receptors (RARs) in skin, we have targeted a dominant-negative RXR alpha (dnRXR alpha) lacking transactivation function AF-2 to differentiated suprabasal keratinocytes in the epidermis of transgenic mice. Driven by the suprabasal-specific keratin-10 gene promoter, expression of dnRXR alpha severely reduced the ability of RAR-selective ligands tRA and CD367 to induce epidermal mRNA levels of the CRABPII, CRBPI, and CRBPII genes, which contain RA-responsive elements (RAREs) DR1 and/or DR2. It also reduced gene-specific, synergistic induction of CRBPI mRNA by a combination of CD367 and RXR-selective SR11237. Like endogenous RXR alpha, dnRXR alpha in epidermal nuclear extracts from the transgenic mice competitively formed heterodimers with endogenous RAR gamma on RAREs, suggesting that dnRXR alpha impairs retinoid signaling by competing with endogenous RAR gamma-RXR alpha heterodimers. Histologically, the epidermis of dnRXR alpha mice showed no detectable developmental abnormalities. Surprisingly, in adult animals, the suprabasal expression of dnRXR alpha significantly reduced the ability of topically applied tRA to stimulate proliferation of undifferentiated keratinocytes in the basal layer of epidermis. RXR-selective ligands alone had no detectable effects on both normal and transgenic mouse epidermis. Accordingly, we suggest that in vivo: (1) in suprabasal keratinocytes, retinoids regulate gene transcription via RAR-RXR heterodimers in which RAR confers a predominant ligand response, whereas RXR AF-2 is required for liganded RAR AF-2 to efficiently trans-activate target genes, and (2) this suprabasal RXR-assisted mechanism indirectly regulates proliferation of basal keratinocytes likely via intercellular signaling.

The application of prostaglandin E1 indirect portal vein angiography and color Doppler ultrasound in patients with post-devascularization portal hypertension

The selection of proper treatment is based on identification of the causes of massive hemorrhage of gastrointestinal tract after pericardial devascularization. The combined use of prostaglandin E1 indirect portal vein angiography, DSA of celiac artery and color Doppler can provide detailed information about portal vein system, including the presence of embolism, spongioid changes and devascularization of left gastric vein and left gastric artery and the direction of blood flow. If these techniques failed to reveal the causes of digestive tract bleeding, the endoscopy may show lesions of gastric mucosa, which could be accountable for the bleeding.

The relationship between the morphology of nucleus of liver cells and the liver functions and prognosis of portal hypertension due to hepatic cirrhosis

The morphology of nucleus of liver cells from 30 patients with portal hypertension due to hepatic cirrhosis and 5 normal persons were measured using an image analyzer coupled with a computer. It was found that the diameters, perimeters, areas and form factor (FF) of the nucleus of liver cirrhosis portal hypertension patients were significantly increased as compared with those of the normal subjects (P < 0.05 or P < 0.01). There was a very significant difference in this parameters between the normal persons and patients with Child-Pugh A liver function or patients with Child-Pugh C liver function (P < 0.01 for both). Significant difference in these parameters existed between the normal persons or patients with Child-Pugh A liver function and patients with liver function of Child-Pugh B (P < 0.05). No significant difference in the parameter of optic density (OD) were found between the normal persons and patients with impairment of liver function of varying degrees (Child-Pugh Classification) (P > 0.05). Our results suggest that the hepatocytes of patients with portal hypertension due to hepatic cirrhosis became juvenile and the morphology of the hepatocytes of patients with impairment of liver function of Child-Pugh C changed obviously. The enlargement and sparsity of nucleus of hepatocytes as revealed by pathological examination is a sign of severe impairment of liver function.

Morphometric measurement of collagen in liver tissue with posthepatitis liver cirrhosis portal hypertension

A correct estimation of the collagen content in cirrhosis liver tissue and analysis of its relation to the degree of liver function injury are important to the clinician in the establishment of the diagnosis in the liver diseases. The author has performed the morphometric measurement of collagen with liver tissue pathological section by using TJTY-300 image analysis system. It was found that the cirrhotic liver tissue's collagen area and collagen average grey degree were notably higher than those in normal men (P < 0.05), average optical density was markedly lower than that in normal men (P < 0.05), integral optical density had no significant difference (P > 0.05) between patients and normal controls, but the integral optical density in cirrhotic liver was 1.21 times that of normal men. It suggests that the collagen content in cirrhotic liver tissue increased obviously, the average density of the increased collagen was lower than that in the normal liver tissue and the density of increased collagen was not homogeneous. Comparison between normal controls and patients with different Child-Pugh liver function grades in liver tissue collagen parameters revealed that the cirrhotic liver's collagen content can, to different degree, directly reflect the function status of cirrhotic liver.

Multi-variate stepwise discriminant analysis research affecting portal hypertension's grade factors of liver function

The ideal time for selecting portal hypertension operation is the accurate judgement of the grade of liver function, yet the present criterion in grading liver function is controversial. 50 patients with 20 factors related to portal hypertension were undergone stepwise discriminant analysis by using SAS software on the IBM/PC computer (significance level alpha = 0.05). The results show that ascites degree prothrombin time (PT), serum total bilirubin, serum albumin content, main portal vein flow are significant factors. In the light of above variates contributing to grading liver function as to establish a discriminant equation, it was found that the total agreement rate between replaceable discrimination and original Child-Pugh classification is 86%. A test for agreement was performed between discriminant and original classification, showing that the two kinds of classification methods have a good agreement rates (Kappa = 0.7856), indicating the discriminant classification is of practical values.

Application of CDFI and portal system pressure measurement in the study of portal hypertension hemodynamics

It has been discovered in portal system hemodynamics research using CDFI and pressure measurement, that among 40 portal hypertension patients the demonstrating rate of left gastric vein (LGV) was 77.5%, and all were hepatofugal. The demonstrating rates of spontaneous splenorenal vein shunt collaterals and of patency umbilical vein (UV) with blood signal were 85%, 12.5% respectively, and the thrombosis rate of portal system was 10%. Blood flow direction of main portal vein (MPV) in all patients was hepatopetal, and one case of superior mesenteric vein (SMV) and another one of splenic vein (SV) were hepatofugal. The patients with MPV thrombosis or portal system hepatofugal should be operated on by shunt. Shunt capacity of portal vein in gastroplenic region was 34.07% on average. This demonstrated that devascularization was applicable. Internal diameter, blood capacity and time average velocity (TAV) of the left portal vein (LPV) and right portal vein (RPV) with portal hypertension were almost equal, their difference being not significant (P > 0.2). This should be a basis for the diagnosis of portal hypertension. Free portal pressure (FPP) and internal diameter, blood capacity and TAV of MPV, SV, SMV, LGV were not correlative with each other.

[Hemodynamics of portal system using color ultrasonography and direct pressure measurement before and after pericardial devascularization]

Controlled study on the portal hemodynamics was carried out before and after pericardial devascularization in 23 patients with portal hypertension. Color ultrasonography detected LGV in 87% of the patients, total prehepatic shunt volume was larger than 46.92%, That through SV more than 15. 48%, and LGV about 15.97%. Hence the total volume shunted through gastrosplenic region was more than 31.45%. Postoperative FPP was significantly decreased (P < 0.05) and SOPP and gastris wall venous pressure increased (P < 0.01). Postoperative PVF did not change significantly. When the ratio of SAV to SVF was less than 1.0, postoperative PVF was significantly increased (P < 0.05). Shunt surgery is the treatment of choice. In the case when the ratio in larger than 1.0, PVF may, decrease (P < 0.01); Patients should receive devascularization. When SVF plus SMVF is greater than PVF, patients should be operated on only with splenectomy or devascularization.