[Applicability of H2FPEF and HFA-PEFF Scores in Chinese Patients Suffering From Heart Failure With Preserved Ejection Fraction and Heart Failure With Preserved Ejection Fraction Complicated With Atrial Fibrillation].

Objective To analyze the diagnostic values of H2FPEF and HFA-PEFF scores for heart failure with preserved ejection fraction (HFpEF) and HFpEF complicated with atrial fibrillation (HFpEF-AF) in Chinese patients and explore the related factors. Methods A cross-sectional study was conducted.A total of 835 consecutive HFpEF patients treated in the Department of Geriatric Cardiology,the First Hospital of Lanzhou University from 2009 to 2020 were selected and assigned to a HFpEF-AF group (n=267) and a HFpEF group (n=568) according to the presence of AF or not.HFA-PEFF and H2FPEF scores were used for retrospective diagnosis and the diagnostic consistency of the two scores was assessed.One hundred and thirty-six healthy volunteers with age and sex matching the patients during the same period were selected as healthy controls.The receiver operating characteristic (ROC) curves were established for H2FPEF and HFA-PEFF scores in diagnosing HFpEF-AF and HFpEF,on the basis of which the diagnostic performance of the two scores was evaluated. Results There was no difference in the HFA-PEFF score between the two groups (P=0.070).However,the HFpEF-AF group had higher mean H2FPEF score and higher proportion of patients with the score no less than 6 than the HFpEF group (P<0.001).According to the ROC curves,HFA-PEFF and H2FPEF scores demonstrated high performance in diagnosing all HFpEF patients,with the area under the curve (AUC) of 0.892 and 0.922 and the optimal cut-offs of 4 and 4,respectively.The HFA-PEFF score showed similar performance in diagnosing HFpEF and HFpEF-AF,with the AUC of 0.899 and 0.911,respectively.The H2FPEF score had higher performance in diagnosing HFpEF-AF (AUC of approximately 1.000) and low performance in diagnosing HFpEF (AUC of 0.885). Conclusions The HFA-PEFF score is applicable in the diagnosis of both HFpEF and HFpEF-AF.The H2FPEF score may underestimate HFpEF in Chinese patients,and its applicability in the Chinese patients with HFpEF alone remains to be investigated.

Interaction between systemic iron parameters and left ventricular structure and function in the preserved ejection fraction population: a two-sample bidirectional Mendelian randomization study.

BACKGROUND: Left ventricular (LV) remodeling and diastolic function in people with heart failure (HF) are correlated with iron status; however, the causality is uncertain. This Mendelian randomization (MR) study investigated the bidirectional causal relationship between systemic iron parameters and LV structure and function in a preserved ejection fraction population. METHODS: Transferrin saturation (TSAT), total iron binding capacity (TIBC), and serum iron and ferritin levels were extracted as instrumental variables for iron parameters from meta-analyses of public genome-wide association studies. Individuals without myocardial infarction history, HF, or LV ejection fraction (LVEF) < 50% (n = 16,923) in the UK Biobank Cardiovascular Magnetic Resonance Imaging Study constituted the outcome dataset. The dataset included LV end-diastolic volume, LV end-systolic volume, LV mass (LVM), and LVM-to-end-diastolic volume ratio (LVMVR). We used a two-sample bidirectional MR study with inverse variance weighting (IVW) as the primary analysis method and estimation methods using different algorithms to improve the robustness of the results. RESULTS: In the IVW analysis, one standard deviation (SD) increased in TSAT significantly correlated with decreased LVMVR (ß = -0.1365; 95% confidence interval [CI]: -0.2092 to -0.0638; P = 0.0002) after Bonferroni adjustment. Conversely, no significant relationships were observed between other iron and LV parameters. After Bonferroni correction, reverse MR analysis showed that one SD increase in LVEF significantly correlated with decreased TSAT (ß = -0.0699; 95% CI: -0.1087 to -0.0311; P = 0.0004). No heterogeneity or pleiotropic effects evidence was observed in the analysis. CONCLUSIONS: We demonstrated a causal relationship between TSAT and LV remodeling and function in a preserved ejection fraction population.

[Cardiac Structural and Functional Features in Patients With Type 2 Diabetes Mellitus and Heart Failure With Preserved Ejection Fraction:A Study Based on Propensity Score Matching].

Objective To investigate the cardiac structural and functional characteristics in the patients with heart failure with preserved ejection fraction (HFpEF) and type 2 diabetes mellitus (T2DM),and predict the factors influencing the characteristics. Methods A total of 783 HFpEF patients diagnosed in the Department of Geriatric Cardiology,the First Hospital of Lanzhou University from April 2009 to December 2020 were enrolled in this study.Echocardiography and tissue Doppler technique were employed to evaluate cardiac structure and function.According to the occurrence of T2DM,the patients were assigned into a HFpEF+T2DM group (n=332) and a HFpEF group (n=451).Propensity score matching (PSM)(in a 1∶1 ratio) was adopted to minimize confounding effect.According to urinary albumin excretion rate (UAER),the HFpEF+T2DM group was further divided into three subgroups with UAER<20 µg/min,of 20-200 µg/min,and>200 µg/min,respectively.The comorbidities,symptoms and signs,and cardiac structure and function were compared among the groups to clarify the features of diabetes related HFpEF.Multivariate linear regression was conducted to probe the relationship of systolic blood pressure,blood glucose,glycosylated hemoglobin,and UARE with cardiac structural and functional impairment. Results The HFpEF+T2DM group had higher prevalence of hypertension (P=0.001) and coronary heart disease (P=0.036),younger age (P=0.020),and larger body mass index (P=0.005) than the HFpEF group,with the median diabetic course of 10 (3,17) years.After PSM,the prevalence of hypertension and coronary heart disease,body mass index,and age had no significant differences between the two groups(all P>0.05).In addition,the HFpEF+T2DM group had higher interventricular septal thickness (P=0.015),left ventricular posterior wall thickness (P=0.040),and left ventricular mass (P=0.012) and lower early diastole velocity of mitral annular septum (P=0.030) and lateral wall (P=0.011) than the HFpEF group.Compared with the HFpEF group,the HFpEF+T2DM group showed increased ratio of early diastolic mitral filling velocity to early diastolic mitral annular velocity (E/e') (P=0.036).Glycosylated hemoglobin was correlated with left ventricular mass (P=0.011),and the natural logarithm of UAER with interventricular septal thickness (P=0.004),left ventricular posterior wall thickness (P=0.006),left ventricular mass (P<0.001),and E/e' ratio (P=0.049). Conclusion The patients with both T2DM and HFpEF have thicker left ventricular wall,larger left ventricular mass,more advanced left ventricular remodeling,severer impaired left ventricular diastolic function,and higher left ventricular filling pressure than the HFpEF patients without T2DM.Elevated blood glucose and diabetic microvascular diseases might play a role in the development of the detrimental structural and functional changes of the heart.

Bibliometric study of soluble guanylate cyclase stimulators in cardiovascular research based on web of science from 1992 to 2021.

Background: Several studies have shown that soluble guanylate cyclase (sGC) stimulators have cardiovascular (CV) benefits. However, few bibliometric analyses have examined this field systematically. Our study aimed to examine the publications to determine the trends and hotspots in CV research on sGC stimulators. Methods: Publications on sGC stimulators in CV research were retrieved from the Web of Science Core Collection. VOSviewer and CiteSpace visualization software were used to analyze publication trends, countries (regions) and institutions, journals and cited journals, authors and cited references, as well as keywords. Results: A total of 1,212 literatures were obtained. From its first appearance in 1992-2021 (based on WOSCC record), the overall volume of publications has shown a gradual increasing trend. Nearly one-third were authored by American scholars, and most were published in Circulation, Circulation Research, and Proceedings of the National Academy of Sciences of the United States of America. Bayer Agency in Germany was the leading driving force, and has a high academic reputation in this field. Stasch JP has published the most related articles and been cited most frequently. Half of the top 10 co-cited references were published in the leading highly co-cited journal Circulation and New England Journal of Medicine. "NO," "allosteric regulation" and "free radicals" were the focus of previous research, "chronic thromboembolic pulmonary hypertension," "pulmonary hypertension" and "heart failure" were the main research hotspots. The key words "chronic thromboembolic pulmonary hypertension," "Pulmonary hypertension," "preserved ejection fraction" and "heart failure" appeared most recently as research frontiers. Conclusion: The research in the CV field of sGC stimulators was relatively comprehensive, and there was a close relationship among countries, research institutions and authors, but it is still in the exploratory stage in the treatment of CV disease. At present, most studies focus on the results of clinical trials. sGC stimulators in the treatment of heart failure, especially heart failure with preserved ejection fraction, may be the hotpots and Frontier at present and in the future, and should be closely monitored.

Erratum to "The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity".

[This corrects the article DOI: 10.34133/2020/2640834.].

The Possibility of Changing the Wettability of Material Surface by Adjusting Gravity.

The contact angle, as a vital measured parameter of wettability of material surface, has long been in dispute whether it is affected by gravity. Herein, we measured the advancing and receding contact angles on extremely low contact angle hysteresis surfaces under different gravities (1-8G) and found that both of them decrease with the increase of the gravity. The underlying mechanism is revealed to be the contact angle hysteresis and the deformation of the liquid-vapor interface away from the solid surface caused by gradient distribution of the hydrostatic pressure. The real contact angle is not affected by gravity and cannot measured by an optical method. The measured apparent contact angles are angles of inclination of the liquid-vapor interface away from the solid surface. Furthermore, a new equation is proposed based on the balance of forces acting on the three-phase contact region, which quantitatively reveals the relation of the apparent contact angle with the interfacial tensions and gravity. This finding can provide new horizons for solving the debate on whether gravity affects the contact angle and may be useful for the accurate measurement of the contact angle and the development of a new contact angle measurement system.

Effects of large gradient high magnetic field (LG-HMF) on the long-term culture of aquatic organisms: Planarians example.

Large gradient high magnetic field (LG-HMF) is a powerful tool to study the effects of altered gravity on organisms. In our study, a platform for the long-term culture of aquatic organisms was designed based on a special superconducting magnet with an LG-HMF, which can provide three apparent gravity levels (µ g, 1 g, and 2 g), along with a control condition on the ground. Planarians, Dugesia japonica, were head-amputated and cultured for 5 days in a platform for head reconstruction. After planarian head regeneration, all samples were taken out from the superconducting magnet for a behavioral test under geomagnetic field and normal gravity conditions. To analyze differences among the four groups, four aspects of the planarians were considered, including head regeneration rate, phototaxis response, locomotor velocity, and righting behavior. Data showed that there was no significant difference in the planarian head regeneration rate under simulated altered gravity. According to statistical analysis of the behavioral test, all of the groups had normal functioning of the phototaxis response, while the planarians that underwent head reconstruction under the microgravity environment had significantly slower locomotor velocity and spent more time in righting behavior. Furthermore, histological staining and immunohistochemistry results helped us reveal that the locomotor system of planarians was affected by the simulated microgravity environment. We further demonstrated that the circular muscle of the planarians was weakened (hematoxylin and eosin staining), and the epithelial cilia of the planarians were reduced (anti-acetylated tubulin staining) under the simulated microgravity environment. Bioelectromagnetics. 2018;39:428-440. © 2018 Wiley Periodicals, Inc.

[Genetics of fertility restoration in the isocytoplasm allonuclear C-group of cytoplasmic male sterility in maize].

Maize is one of the first crops to produce hybrids using cytoplasmic male sterile lines. The C-type cytoplasmic male sterile (CMS-C) line is vital for hybrid seed production, and the fertility-restoration reaction along with its stability has a direct bearing on its applications. However, fertility restoration mechanism of CMS-C is complex and is still not clear so far. To further explore the factors affecting the fertility restoration of maize CMS, a series of test crosses were carried out by pollinating the isocytoplasm allonuclear CMS-C lines C48-2, Chuangzaosi and C478 with the test lines 18 bai, zi 330, 5022 and the restorer line A619, respectively. Four F2 populations and six double-cross combinations were obtained from the self-cross of fertility restored F1 and pollinating male-sterility-maintained F1 with the male-fertility-restored F1, respectively. Meanwhile, we developed the incomplete diallel-cross combinations using the isocytoplasm allonuclear male sterile lines as maternal parents and their respective maintainer lines 48-2, huangzaosi and 478 as paternal parents. All the F1, F2 and double-cross populations were planted at distinct locations in different years, and the fertility-restoration reaction was scored by field investigation and pollen staining with I2-IK. The results were as follows: 1) The same test line could restore the CMS-C line at a certain genetic background, but failed to restore the CMS-C line at the other genetic backgrounds, suggesting that the genetic background of CMS-C lines plays an important role in the fertility restoration. 2) The fertile-to-sterile segregation ratio of (C48-2×A619) F2 population planted in both Sichuan and Yunnan fited well to 15:1 by the χ 2 test. However, the fertility level of individuals in Yunnan mainly belonged to the 3 and 4grades, but which in Sichuan mainly belonged to the 5 grade, indicating the environmental factors had effect on the fertility-restoration reaction of (C48-2×A619) F2. 3) In our study, 18 bai could not restore C478, and 48-2 could not restore C478, but the fertile and sterile segregated plants were unexpectedly found in their double-cross population [(C478×18 bai) F1S×(C48-2×18 bai) F1F]. The similar case was also observed in the double-cross population [(C48-2 × zi 330) F1S × (C478 × zi 330) F1F]. Therefore, we speculated that there are minor fertility restorer genes not only in the nuclear background of C48-2 and C478, but also in zi 330 and 18 bai, and when these minor genes were gathered by hybridization, they could restore the fertility of C478 and C48-2. This conforms to the restorer genes dose-effect for fertility restoration in the plant CMS system. These results not only contribute to our understanding of the complexity and diversity of CMS-C restoration mechanism, but also provide an important reference for the practical applications about maize CMS-C.

Correlation between the GP78 Gene Polymorphism and Coronary Atherosclerotic Heart Disease.

OBJECTIVE: To study the correlation between the GP78 gene polymorphism and blood fat, blood glucose, blood pressure and coronary atherosclerotic heart disease. METHODS: A total of 72 patients with coronary atherosclerotic heart disease were selected as the observation group, and 68 healthy participants were selected as the control group. The gp78 gene polymorphism of both groups was studied via polymerase chain reaction-restriction fragment length polymorphism (RFLP). At the same time, the multiple expression quantities of the GP78 gene in the tissues of both groups were tested via fluorogenic quantitative PCR, enzyme-linked immunosorbent assay (ELISA) and Western-blotting assay. Furthermore, the blood fat, blood glucose and blood pressure of subjects in both groups were tested. RESULTS: The percentages of the gp78 gene polymorphisms of Arg/Arg, Arg/Gly and Gly/Gly at the 145 locus of the study subjects in the observation group were 12.3%, 43.2% and 44.5%, respectively, while those in the control group were 74.3%, 11.2% and 14.5%, respectively, and there were significant differences between both groups. Based on the test results of the blood fat, blood glucose and blood pressure of the objects in the observation group and control group, significant differences were found between the two groups (P<0.05). CONCLUSION: There was a significant correlation between the 145 locus of the gp89 gene and coronary atherosclerotic heart disease, indexes of blood fat, blood glucose and blood pressure.

Measurement of contact angles in a simulated microgravity environment generated by a large gradient magnetic field.

The contact angle is an important parameter that is essential for studying interfacial phenomena. The contact angle can be measured using commercially available instruments. However, these well-developed instruments may not function or may be unsuitable for use in some special environments. A simulated microgravity generated by a large gradient magnetic field is such an environment in which the current measurement instruments cannot be installed. To measure the contact angle in this environment, new tools must be designed and manufactured to be compatible with the size and physical environment. In this study, we report the development and construction of a new setup that was specifically designed for use in a strong magnetic field to measure the contact angle between a levitated droplet and a solid surface. The application of the setup in a large gradient magnetic field was tested, and the contact angles were readily measured.

A novel rotating experimental platform in a superconducting magnet.

This paper introduces a novel platform designed to be used in a strong static magnetic field (in a superconducting magnet). The platform is a sample holder that rotates in the strong magnetic field. Any samples placed in the platform will rotate due to the rotation of the sample holder. With this platform, a number of experiments such as material processing, culture of biological systems, chemical reactions, or other processes can be carried out. In this report, we present some preliminary experiments (protein crystallization, cell culture, and seed germination) conducted using this platform. The experimental results showed that the platform can affect the processes, indicating that it provides a novel environment that has not been investigated before and that the effects of such an environment on many different physical, chemical, or biological processes can be potentially useful for applications in many fields.

Research progress on mechanisms of male sterility in plants based on high-throughput RNA sequencing.

Male sterility is defined as failing to produce functional pollen during stamen development in plants, and it plays a crucial role in plant reproductive research and hybrid seed production in utilization of crop heterosis. High throughput RNA sequencing (RNA-seq) has been used widely in the study of different fields of life science, as it readily detects all the mRNA and non-coding RNA in cells. Recently, RNA-seq has been reported to be applied in different species and kinds of pollen abortion types in plants, which has contributed to the understanding of the molecular mechanism and metabolic networks of male sterility at the transcription level. In this review, we summarize research progress on the mechanisms of male sterility in plants, focusing on RNA-seq analysis encompassing strategies of RNA library construction, differentially expressed genes and functional characteristics of noncoding RNAs involved in stamen abortion. Furthermore, we also discuss application of transcriptome sequencing technology to elucidate pollen abortion mechanisms and map fertility-related genes. We hope to provide references to the study of male sterility in plants.

[Effect of Kanli Granule on Myocardial Mechanics in Pressure Overload Induced Diastolic Heart Failure Rats].

OBJECTIVE: To observe the effect of Kanli Granule (KG) on myocardial mechanics in pressure overload induced diastolic heart failure (DHF) rats. METHODS: Totally 60 male Wistar rats were divided into the sham-operation group, the model group, the KG group, and the Valsartan group according to random digit table, 15 in each group. The pressure overload induced DHF model was established in all groups except the sham-operation group using abdominal aortic constriction surgery. Totally 7 rats died after modeling (with the mortality of 10. 67%) , and the rest 53 finished the following test. Rats in the KG group were administered with KG extract (calculated as 6. 75 g crude drug/kg) by gastrogavage. Rats in the Valsartan group were administered with Valsartan (7.2 µg/g) by gastrogavage. Equal volume of double distilled water was administered to rats in the model group and the sham-operation group by gastrogavage. All rats were intervened for 32 weeks. The response of isolated heart papillary muscle tonus to isoprenaline (ISO) and adenylate cyclase (Forskolin) was respectively observed. The enhancement phenomenon after resting development force (DF) of isolated heart papillary muscle tonus, and changes of DF in different Ca²âº concentrations were observed. RESULTS: (1) In the ISO response test: Compared with the sham-operation group, the amplifications of DF, ±df/dt, -df/dt were obviously elevated in the model group (P < 0.05). Compared with the model group, the amplifications of DF and ±df/dt were obviously lowered in the KG group (P < 0.01), and the amplification of ±df/dt was also reduced in the Valsartan group (P < 0.01). (2) In the Forskolin response test: Compared with the sham-operation group, the amplifications of DF and ±df/dt obviously increased in the model group (P < 0.05). Compared with the model group, the amplifications of DF and ±df/dt were obviously reduced in the KG group (P < 0.01), and the amplification of DF was also reduced in the Valsartan group (P < 0.05). (3) In post-resting DF enhancement test: Compared with the sham-operation group, the amplification of DF showed gradually decreasing tendency along with prolonged resting time in the model group, and they were obviously lowered at all time points (P < 0.05). Compared with the model group, the amplification of DF was gradually increasing along with prolonged resting time in the KG group. The amplification of DF at post-resting 240 s was obviously larger in the KG group than in the model group (P < 0.05). The amplification of post-resting DF still showed gradually decreasing tendency along with prolonged resting time in the Valsartan group, with increased amplifications of DF at post-resting 60 s and 120 s (P < 0. 05) (4) The amplifications of DF in different Ca²âº concentrations: Compared with the sham-operation group, the amplifications of DF were significantly elevated in different Ca²âº concentrations (1.75, 3.5, 7.0 mmol/L ) (P < 0.05, P < 0.01). Compared with the model group, there was no statistical difference in amplification of DF in different Ca²âº concentrations in the KG group (P > 0.05). The amplifications of DF in different Ca²âº concentrations were significantly reduced in the Valsartan group (P < 0.05). CONCLUSIONS: The ISO response and the Forskolin response were enhanced in isolated heart papillary muscle tonus of pressure overload induced DHF rats; enhanced post-resting DF was reduced; DF in different supra-physiologic levels of Ca²âº was still enhanced. KG could significantly improve excessive enhancement of pressure overload induced DHF rats in ISO response and Forskolin response, and improve enhancement of post-resting myocardium.

[Measuring the Spectrum of Extinction Coefficient and Reflectance for Cadmium Compounds from 400 to 900 nm].

The key to extract the contents of cadmium in water by using remote sensing technique is to measure the spectrum of extinction coefficient per g·L(-1) and reflectance for its compounds. So in this paper, firstly, we choose two kinds of cadmium compounds, cadmium sulfide (CdS) and cadmium oxide (CdO), which are most commonly exsit in natural water, to measure the spectrums of extinction coefficient and reflectance for them. We use the equipment, designed on our own, which can adjust the path length of light passing and make our measuring results more accurate at visible and near-infrared wavelength range than others. Then we use Analytical Spectral Devices (ASD) spectrometer to measure the radiance of the light spot, which is from the direct light passed through cadmium compounds solutions of different concentrations reflected by the standard board. Using the ratio method to eliminate environmental errors and the effects of the thimbleful of suspended solids in water, we obtain the extinction coefficient per g·L(-1) of these two kinds of cadmium compounds from 400 to 900 nm. Secondly, we use ASD spectrometer to measure the reflectance spectrum of them in the sunny day at outdoor. The reflectance we obtain in this paper can help us to calculate the absorption and scattering coefficient per g·L(-1) in the future. The measuring results show that the extinction coefficient spectrum of CdS has two troughs at 550 and 830 nm and one peak at 675 nm. And the extinction coefficient spectrum of CdO decrease from purple to near-infrared. Both of their coefficient spectrums in blue are larger than green and red. And the value of the extinction coefficient per g·L(-1) of CdS is larger than CdO in the whole measuring wavelength range. The reflectance of CdS in yellow and red is larger than purple and blue, which increases rapidly from 500 to 650 nm and then leveling off. While the reflectance of CdO increase linearly from 525 to 900 nm. Both have obvious spectral characteristic. According to our results, the largest extinction coefficient appear at blue color, while the largest reflectance appear at yellow and red, which means that those bands are the most sensitive wavelength to detect the change of cadmium concentration in water. This study carries out with optical parameters measurements for optical activity of cadmium compounds specifically for water quality remote sensing for the first time. We conclude that the extinction coefficient and reflectance spectrums we obtained are reasonable, and the results can be used as the base parameter in the remote sensing inversion model for cadmium contents in water, which provides a breakthrough on using remote sensing technique to extract the heavy metal contents in water. Obtained these two optical parameters in this paper can provide powerful reference for band selection of the remote sensing image, which is used to extract cadmium contents in water, as well as provide the necessary important parameters of the remote sensing inversion model of cadmium contents in water.

[Research progress of the bHLH transcription factors involved in genic male sterility in plants].

Male sterility exists widely in the spermatophytes. It contributes to the study of plant reproductive development and can be used as an effective tool for hybrid seed production in heterosis utilization. Therefore, the study on male sterility is of great value in both theory and application. As one of the largest transcription factor families in plants, basic helix-loop-helix proteins (bHLHs) play a crucial role in regulating plant growth and development. This paper introduces the mechanism of bHLH regulating stamen development in several important model plants. Furthermore, we discuss the molecular mechanisms of genic male sterility resulting from bHLH dysfunction to provide references for crop breeding and theoretical studies.

An ignored variable: solution preparation temperature in protein crystallization.

Protein crystallization is affected by many parameters, among which certain parameters have not been well controlled. The temperature at which the protein and precipitant solutions are mixed (i.e., the ambient temperature during mixing) is such a parameter that is typically not well controlled and is often ignored. In this paper, we show that this temperature can influence protein crystallization. The experimental results showed that both higher and lower mixing temperatures can enhance the success of crystallization, which follows a parabolic curve with an increasing ambient temperature. This work illustrates that the crystallization solution preparation temperature is also an important parameter for protein crystallization. Uncontrolled or poorly controlled room temperature may yield poor reproducibility in protein crystallization.

Utilisation of adsorption and desorption for simultaneously improving protein crystallisation success rate and crystal quality.

High-quality protein crystals of suitable size are an important prerequisite for applying X-ray crystallography to determine the 3-dimensional structure of proteins. However, it is often difficult to obtain protein crystals of appropriate size and quality because nucleation and growth processes can be unsuccessful. Here, we show that by adsorbing proteins onto porous polystyrene-divinylbenzene microspheres (SDB) floating on the surface of the crystallisation solution, a localised high supersaturation region at the surface of the microspheres and a low supersaturation region below the microspheres can coexist in a single solution. The crystals will easily nucleate in the region of high supersaturation, but when they grow to a certain size, they will sediment to the region of low supersaturation and continue to grow. In this way, the probability of crystallisation and crystal quality can be simultaneously increased in a single solution without changing other crystallisation parameters.

[Establishment of a method to detect duck hepatitis B virus covalently closed circular DNA based on rolling circle amplification].

Rolling circle amplification (RCA) is a newly developed experimental technique that can specific ally amplify circular DNA. Since 2008, RCA has been extensively used in hepatitis B virus (HBV) research, such as the amplification of the full-length sequence of the HBV genome, and the analysis of the drug-resistant mutations of HBV covalently closed circular DNA (cccDNA), amongst others. To create an easy assay for the analysis of duck hepatitis B virus (DHBV) cccDNA, this study established an RCA-based method. DHBV cccDNA was amplified from the DHBV DNA samples of duck liver with four pairs of sulfur-modified primers, which were designed according to the highly conserved sequence of DHBV using sera DHBV DNA as the negative control. DHBV cccDNA was detected in the obtained RCA products by the sequencing of RCA amplicons that were amplified with primer pairs on both sides of the gap of DH BV relaxed circular DNA, rather than by digesting RCA products with a restriction enzyme. The liver and sera DHBV DNA samples of 39 ducks infected with DHBV were examined with the RCA-based DHBV cccDNA detection method, and the results showed that while DHBV cccDNA was detected from all 39 liver DHBV DNA samples, no DHBV cccDNA was found in any of the sera DHBV DNA samples. These results suggest that the method established in the study is highly specific and sensitive for the detection of DHBV cccDNA. The establishment of this RCA-based DHBV method for cccDNA detection lays the groundwork for using a DHBV model to study the role of cccDNA in the pathogenesis of hepatitis B and to evaluate the effect of anti-virus therapies.

Promoting protein crystallization using a plate with simple geometry.

Increasing the probability of obtaining protein crystals in crystallization screening is always an important goal for protein crystallography. In this paper, a new method called the cross-diffusion microbatch (CDM) method is presented, which aims to efficiently promote protein crystallization and increase the chance of obtaining protein crystals. In this method, a very simple crystallization plate was designed in which all crystallization droplets are in one sealed space, so that a variety of volatile components from one droplet can diffuse into any other droplet via vapour diffusion. Crystallization screening and reproducibility tests indicate that this method could be a potentially powerful technique in practical protein crystallization screening. It can help to obtain crystals with higher probability and at a lower cost, while using a simple and easy procedure.

[Effect of protein on the detection of antipsychotic drug residues in human serum and its elimination].

Using pure human serum albumin (HSA) as the model protein, the effects of protein on the extraction of antipsychotic drugs (APDs: diazepam, chlorpromazine hydrochloride, and perphenazine) in human serum sample were studied. The present paper investigated the interaction between APDs and HSA by fluorescence spectrometry in detail The influences of different ethanol concentration solution on protein denaturation were studied by Rayleigh scattering. The results showed that APDs strongly bound with HSA. In the phi (ethanol) 80% extracting solution, a slow but full protein denaturation takes place, which causes the unfolding of protein and the dissociation of drugs. Then K2 HPO4 was added into the extracting solution to form aqueous two-phase system, and meanwhile the drug residues were extracted into upper phase with high extraction efficiencies. After filtration, the upper phase was ready for analysis of drug residues by HPLC system. The detection limits were in the range of 18.8-38.4 ng x mL(-1), and the spiked recovery was 94.2%-98.7% for determination of antipsychotic drugs in human serum. The method is efficient, solvent-saving, environment-friendly, and accurate.