GTP-Binding Protein 1-Like (GTPBP1l) Regulates Vascular Patterning during Zebrafish Development.

Genetic regulation of vascular patterning is not fully understood. Here, we report a novel gene, gtpbp1l (GTP-binding protein 1-like), that regulates vascular development in zebrafish. Amino acid sequence comparison and a phylogenetic study showed that gtpbp1l is conserved in vertebrates. Gtpbp1l mRNA is expressed in the vasculature during embryogenesis. Knockdown of gtpbp1l by morpholino impairs the patterning of the intersegmental vessel (ISV) and caudal vein plexus (CVP), indicating the role of gtpbp1l in vasculature. Further apoptosis assays and transgenic fish tests suggested that vascular defects in gtpbp1l morphants are not due to cell death but are likely caused by the impairment of migration and proliferation. Moreover, the altered expression of vessel markers is consistent with the vascular defects in gtpbp1l morphants. Finally, we revealed that gtpbp1l is regulated by VEGF/notch and BMP signaling. Collectively, these findings showed that gtpbp1l plays a critical role in vascular patterning during zebrafish development.

Efficacy and safety of traditional chinese medicine treatment for overweight and obese individuals: A systematic review and meta-analysis.

Background: The prevalence of obesity is increasing worldwide, causing a global health issue. Traditional Chinese medicine (TCM) used in treating overweight/obesity has been widely implemented in clinical practice, but its overall efficacy and safety remain unclear. This review aims to evaluate the effectiveness and safety of TCM based on randomized controlled trials (RCTs). Methods: A systematic review was conducted by searching PubMed, Cochrane Library, Web of Science, Embase, and Clinical Trails from their inception to March 2021. Two reviewers screened studies, extracted the data, and assessed the risk of bias independently. The data were pooled for meta-analysis or presented narratively. Results: Twenty-five RCTs involving 1,947 participants were included. Compared with placebo or blank control, TCM preparations reduced Body Mass Index (BMI) [MD = -1.16; 95% confidence interval (CI) = -1.44, -0.89; I2 = 34%], reduced weight (MD = -2.53; 95% CI = -3.08, -1.99; I2 = 34%), reduced waist circumference (MD = -2.64; 95% CI = -3.42, -1.87; I2 = 0%), reduced hip circumference (MD = -3.48; 95% CI = -4.13, -2.83; I2 = 0%), reduced total cholesterol (TCHO) (MD = -10.45; 95% CI = -18.92, -1.98; I2 = 63%), reduced triglycerides (TG) (MD = -4.19; 95% CI = -6.35, -2.03; I2 = 25%), increased high-density lipoprotein (HDL) (MD = -3.60; 95% CI = -6.73, -0.47; I2 = 81%), reduced fasting blood glucose (FBG) (MD = -0.77; 95% CI = -1.24, -0.29; I2 = 91%). Glycated hemoglobin (HbA1c)、body fat rate、low-density lipoprotein (LDL) were not statistically significant. For people with hypertension, decreased systolic blood pressure (SBP) (MD = -5.27; 95% CI = -8.35, -2.19; I2 = 58%), decreased diastolic blood pressure (DBP) (MD = -4.30; 95% CI = -5.90, -2.69; I2 = 0%). For people with normal blood pressure, there was no significant change. There was no significant difference in liver function. Conclusion: It has been demonstrated that TCM preparations have good clinical efficacy and safety for overweight/obesity. TCM may be suitable for overweight/obesity in adult populations for its efficacy and safety of long-term treatment.

Evidence and Potential Mechanisms of Traditional Chinese Medicine for the Adjuvant Treatment of Coronary Heart Disease in Patients with Diabetes Mellitus: A Systematic Review and Meta-Analysis with Trial Sequential Analysis.

Traditional Chinese medicine (TCM) has long been used to treat diabetes mellitus and angina. It has also gained widespread clinical applications in China as a common adjuvant treatment. Although there is high-quality evidence that TCM is effective in regulating glucose and lipid metabolism, the cardiovascular protective effect of TCM in the treatment of diabetes mellitus has not been fully elucidated, especially in patients with both diabetes mellitus and coronary heart disease (CHD). We systematically assessed the efficacy and safety of TCM for the adjuvant treatment of patients with CHD and diabetes mellitus and examined the pharmacological effects and potential mechanisms of TCM medication/herbs on diabetes mellitus with CHD. We found that TCM could improve the control effect of conventional treatment on cardiac function, hemorheology, blood glucose, blood lipid, and inflammation, thus reducing the frequency of angina and the incidence of cardiovascular events and all-cause mortality. These findings indicate that TCM may be used as a complementary approach for patients with diabetes mellitus and CHD. Nevertheless, more rigorously designed randomized controlled trials and long-term evaluations are needed to support these findings.

Nitrobenzoate-Derived Compound X8 Impairs Vascular Development in Zebrafish.

Proper growth and patterning of blood vessels are critical for embryogenesis. Chemicals or environmental hormones may interfere with vascular growth and cause developmental defects. Nitrobenzoate-based compounds have been demonstrated to have a wide range of biological and pharmacological functions, leading to the development of numerous 4-nitrobenzoate derivatives for clinical application. In this study, we tested a novel nitrobenzoate-derived compound, X8, and investigated its effects on vascular development using zebrafish as a model organism. We first determined the survival rate of embryos after the addition of exogenous X8 (0.5, 1, 3, 5, and 10 µM) to the fish medium and determined a sublethal dose of 3 µM for use in further assays. We used transgenic fish to examine the effects of X8 treatment on vascular development. At 25-32 h postfertilization (hpf), X8 treatment impaired the growth of intersegmental vessels (ISVs) and caudal vein plexuses (CVPs). Moreover, X8-treated embryos exhibited pericardial edema and circulatory defects at 60-72 hpf, suggesting the effects of X8 in vasculature. Apoptosis tests showed that the vascular defects were likely caused by the inhibition of proliferation and migration. To investigate the molecular impacts underlying the defects in the vasculature of X8-treated fish, the expression levels of vascular markers, including ephrinb2, mrc1, and stabilin, were assessed, and the decreased expression of those genes was detected, indicating that X8 inhibited the expression of vascular genes. Finally, we showed that X8 treatment disrupted exogenous GS4012-induced angiogenesis in Tg(flk:egfp) zebrafish embryos. In addition, vascular defects were enhanced during cotreatment with X8 and the VEGFR2 inhibitor SU5416, suggesting that X8 treatment causes vascular defects mediated by disruption of VEGF/VEGFR2 signaling. Collectively, our findings indicate that X8 could be developed as a novel antiangiogenic agent.

Identification of Novel Vascular Genes Downstream of Islet2 and Nr2f1b Transcription Factors.

The genetic regulation of vascular development is not elucidated completely. We previously characterized the transcription factors Islet2 (Isl2) and Nr2f1b as being critical for vascular growth. In this study, we further performed combinatorial microarrays to identify genes that are potentially regulated by these factors. We verified the changed expression of several targets in isl2/nr2f1b morphants. Those genes expressed in vessels during embryogenesis suggested their functions in vascular development. We selectively assayed a potential target follistatin a (fsta). Follistatin is known to inhibit BMP, and BMP signaling has been shown to be important for angiogenesis. However, the fsta's role in vascular development has not been well studied. Here, we showed the vascular defects in ISV growth and CVP patterning while overexpressing fsta in the embryo, which mimics the phenotype of isl2/nr2f1b morphants. The vascular abnormalities are likely caused by defects in migration and proliferation. We further observed the altered expression of vessel markers consistent with the vascular defects in (fli:fsta) embryos. We showed that the knockdown of fsta can rescue the vascular defects in (fli:fsta) fish, suggesting the functional specificity of fsta. Moreover, the decreased expression of fsta rescues abnormal vessel growth in isl2 and nr2f1b morphants, indicating that fsta functions downstream of isl2/nr2f1b. Lastly, we showed that Isl2/Nr2f1b control vascular development, via Fsta-BMP signaling in part. Collectively, our microarray data identify many interesting genes regulated by isl2/nr2f1b, which likely function in the vasculature. Our research provides useful information on the genetic control of vascular development.

Interaction of transcription factors Islet2 and Nr2f1b to control vascular patterning during zebrafish development.

Many regulators controlling arterial identity are well described; however, transcription factors that promote vein identity and vascular patterning have remained largely unknown. We previously identified the transcription factors Islet2 (Isl2) and Nr2f1b required for specification of the vein and tip cell identity mediated by notch pathway in zebrafish. However, the interaction between Isl2 and Nr2f1b is not known. In this study, we report that Nr2f2 plays minor roles on vein and intersegmental vessels (ISV) growth and dissect the genetic interactions among the three transcription factors Isl2, Nr2f1b, and Nr2f2 using a combinatorial knockdown strategy. The double knockdown of isl2/nr2f1b, isl2/nr2f2, and nr2f1b/nr2f2 showed the enhanced defects in vasculature including less completed ISV, reduced veins, and ISV cells. We further tested the genetic relationship among these three transcription factors. We found isl2 can regulate the expression of nr2f1b and nr2f2, suggesting a model where Isl2 functions upstream of Nr2f1b and Nr2f2. We hypothsized that Isl2 and Nr2f1b can function together through cis-regulatory binding motifs. In-vitro luciferase assay results, we showed that Isl2 and Nr2f1b can cooperatively enhance gene expression. Moreover, co-immunoprecipitation results indicated that Isl2 and Nr2f1b interact physically. Together, we showed that the interaction of the Nr2f1b and Nr2f2 transcription factors in combination with the Islet2 play coordinated roles in the vascular development of zebrafish.

Effectiveness of the Shenzhuo formula in the treatment of patients with macroalbuminuria secondary to diabetic kidney disease: protocol update and statistical analysis plan.

BACKGROUND: Diabetic kidney disease (DKD) is a significant complication of diabetes and has garnered considerable attention. Our previous retrospective study indicated that Shenzhuo formula (SZF) potentially reduces macroalbuminuria secondary to DKD. METHODS: This trial is a 24-week, randomized, multicentric, double-blinded, double-dummy clinical trial. A total of 120 patients with DKD will be equally and randomly divided into two groups: SZF+ irbesartan simulator or irbesartan + SZF simulator. The 24-h urinary protein change from baseline to week 24 is the primary outcome measure. The secondary outcome measures include serum creatinine, estimated glomerular filtration rate, urinary albumin excretion rate, improvement in traditional Chinese medicine symptoms, fasting blood glucose, 2-h postprandial plasma glucose, hemoglobin A1c, cholesterol, triglycerides, high density lipoprotein, low density lipoprotein, blood pressure, albumin to creatinine ratio, and the Audit of Diabetes-Dependent Quality of Life 19. Our recruitment began in May 2015; currently, we have recruited 100 participants, with a designed maximum sample size of 120. The interim results were reviewed at N = 60, and continuing recruitment was recommended. This statistical analysis plan includes our approach to missing data imputation, primary and secondary outcomes analyses, and safety endpoints. DISCUSSION: This statistical analysis plan will standardize the clinical trial's statistical analysis and avoid outcome selective reporting bias and data-driven analysis. This trial will provide further clinical evidence regarding the effectiveness of SZF in managing macroalbuminuria secondary to DKD. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-ICR-15006311. Registered on 26 May 2013. http://www.chictr.org.cn/showproj.aspx?proj=10862.

Cordyceps cicadae Prevents Renal Tubular Epithelial Cell Apoptosis by Regulating the SIRT1/p53 Pathway in Hypertensive Renal Injury.

Hypertensive renal injury is a primary etiology of end-stage renal disease, and satisfactory therapeutic strategies are urgently required. Cordyceps cicadae, a traditional Chinese herb, has potential renoprotective benefits and is widely used in the treatment of many kidney diseases. To investigate the mechanisms underlying the renoprotective effect of C. cicadae on hypertensive renal injury, we studied the effect of C. cicadae on tubular epithelial cells (TECs) in a spontaneously hypertensive rat (SHR) model and angiotensin II- (AngII-) cultured primary TECs. Our study showed that C. cicadae treatment could decrease 24-hour urine albumin, albumin-to-creatinine ratio (ACR), ß2-MG level, and kidney injury molecule-1 (kim-1) level in SHR urine, alleviate interstitial fibrosis, and reduce α-smooth muscle actin (α-SMA) expression in SHR kidney. In primary TECs, medicated serum containing C. cicadae (CSM) might significantly reduce the AngII-induced production of kim-1 and neutrophil gelatinase-associated lipocalin (NGAL). Furthermore, C. cicadae treatment could decrease TEC apoptosis in SHRs as assessed by the terminal transferase-mediated biotin dUTP nick-end labeling (TUNEL) assay. CSM could inhibit caspase-3 activity and enhance cellular viability as measured by methyl thiazolyl tetrazolium in AngII-cultured TECs, suggesting that CSM might reduce the apoptosis level in TECs induced by AngII. We found that the SIRT1 expression level was markedly lowered, while the protein level of acetylated-p53 was elevated in the TECs of patients with hypertensive renal injury and SHRs. C. cicadae presented the effect of regulating the SIRT1/p53 pathway. Further SIRT1 inhibition with EX527 reversed the effect of C. cicadae on AngII-induced apoptosis. Taken together, our results indicate that C. cicadae offers a protective effect on TECs under hypertensive conditions, which may be related to its antiapoptotic effect through regulation of the SIRT1/p53 pathway.

Efficacy of Intermittent or Continuous Very Low-Energy Diets in Overweight and Obese Individuals with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analyses.

OBJECTIVE: This study is aimed at investigating the efficacy of a very low-energy diet (VLED) in overweight and obese individuals with type 2 diabetes mellitus (T2DM). METHODS: We thoroughly searched eight electronic resource databases of controlled studies concerning the efficacy and acceptability of intermittent or continuous VLEDs in patients with T2DM compared with other energy restriction interventions. RESULTS: Eighteen studies (11 randomized and seven nonrandomized controlled trials) with 911 participants were included. The meta-analyses showed that compared with a low-energy diet (LED) and mild energy restriction (MER), VLED is superior in the reduction of body weight (mean difference (MD) MDLED = -2.77, 95% confidence interval (CI) CILED = -4.81 to - 0.72, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, I 2 = 0%) and TG level (MD = -0.25, 95%CI = -0.55 to 0.06, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, I 2 = 0%) and TG level (MD = -0.25, 95%CI = -0.55 to 0.06, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39, P LED = 0.008; MDMER = -6.72, 95%CIMER = -10.05 to - 3.39. CONCLUSION: Dietary intervention through VLEDs is an effective therapy for rapid weight loss, glycemic control, and improved lipid metabolism in overweight and obese individuals with T2DM. Thus, VLEDs should be encouraged in overweight and obese individuals with T2DM who urgently need weight loss and are unsuitable or unwilling to undergo surgery. As all outcome indicators have low or extremely low quality after GRADE evaluation, further clinical trials that focus on the remission effect of VLEDs on T2DM are needed.

Cisplatin induces chemoresistance through the PTGS2-mediated anti-apoptosis in gastric cancer.

It has been proposed that the aberrant expressions of the classical apoptosis-related genes and the subsequent decrease of apoptosis contribute to the development of cisplatin resistance in gastric cancer. However, little is known about the correlation and the molecular regulation mechanisms of cisplatin and the apoptosis-related gene expressions. Herein, we first identified the expressions of the anti-apoptotic BCL2 and the prostaglandin-endoperoxide synthase-2 (PTGS2) genes, which were abundant in the gastric carcinoma and associated with poor patient survival, were closely related with the resistance against cisplatin. Further investigations revealed that PTGS2 served as an essential mediator involved in the developing process of the resistance against cisplatin via mediating the inhibition effects of cisplatin on BCL2 expression. Mechanistically, cisplatin induced PTGS2 expression through ROS/NF-κB pathway. In addition, PTGS2 mediated cisplatin-induced BCL2 expression and subsequent resistance to apoptosis via PGE2/EP4/MAPKs (ERK1/2, P38) axis. Analysis of the clinical specimens demonstrated that PTGS2 and BCL2 were positively correlated in human gastric cancer. Moreover, in the xenograft models, inhibition of PTGS2 by celecoxib significantly augmented the cytotoxic efficacy of cisplatin in the resistant gastric cancer via suppression of PTGS2 and BCL2 expressions regulated by ERK1/2 and P38 signal axis, suggesting PTGS2 might be employed as an adjunctive therapeutic target for reversal of the chemoresistance in a subset of cisplatin resistant gastric cancer.

Antitumor effect of a short peptide on p53-null SKOV3 ovarian cancer cells.

Fibroblast growth factor-2 (FGF2) is a protein ligand, which exerts essential roles in development, angiogenesis, and tumor progression via activation of the downstream signaling cascades. Accumulating evidence has demonstrated that FGF2 is involved in the progression of ovarian cancer, providing a novel potential target for ovarian cancer therapy. In this study, we showed that FGF2 is significantly increased in ovarian tumors, and is negatively associated with the overall survival of ovarian cancer by database analysis. A short peptide obtained from a heptapeptide phage display library suppressed FGF2-induced proliferation, migration, and invasion of the p53-null epithelial ovarian cancer (EOC) cells. Further investigations revealed that the short peptide antagonized the effects of FGF2 on G0/G1 to S cell phase promotion, cyclin D1 expression, and MAPK and Akt signaling activation, which might contribute to the mechanism underlying the inhibitory effects of the short peptide on the aggressive phenotype of the ovarian cancer cells triggered by FGF2. Moreover, the short peptide might have the potentials of reversing FGF2-induced resistance to the doxorubicin via downregulation of the antiapoptotic proteins and counteracting of the antiapoptotic effects of FGF2 on p53-null EOC cells. Taken together, the short peptide targeting FGF2 may provide a novel strategy for improving the therapeutic efficiency in a subset of EOC.

The Role of Prostaglandin-Endoperoxide Synthase-2 in Chemoresistance of Non-Small Cell Lung Cancer.

The prostaglandin-endoperoxide synthase-2 (PTGS2) plays essential roles in diverse pathological process. Although recent studies implied that PTGS2 was closely related with chemoresistance, the precise roles and the underlying mechanisms of PTGS2 in the developing process of chemoresistance in non-small cell lung cancer (NSCLC) remained elusive. In the present study, we revealed a novel molecular mechanism of PTGS2 implicated in the chemoresistance of NSCLC and proposed a model for the positive feedback regulation of PTGS2 in the process of developing resistance phenotype in NSCLC cells. Our results demonstrated that cisplatin induced PTGS2 expression through the ROS-ERK1/2-NF-κB signaling axis. The prostaglandin E2 (PGE2) derived from PTGS2 catalyzation further strengthened PTGS2 expression via the PGE2-EPs-ERK1/2 positive feedback loop, which induced multidrug resistance of NSCLC cells through up-regulation of BCL2 expression and the subsequent attenuation of cell apoptosis. Consistently, high levels of both PTGS2 and BCL2 were closely associated with poor survival in NSCLC patients. Inhibition of PTGS2 significantly reversed the chemoresistance in the resistant NSCLC in vitro and in vivo. Our results suggested that PTGS2 might be employed as an adjunctive therapeutic target for improving the response to the therapeutic agents in a subset of resistant NSCLC.

The effect of probiotic and synbiotic supplementation on biomarkers of inflammation and oxidative stress in diabetic patients: A systematic review and meta-analysis of randomized controlled trials.

The role of gut microbiota in the management of diabetes has been shown. Several current trials are investigating the effect of probiotics and prebiotics, which are widely used to modulate intestinal microbiota, on inflammatory factors and biomarkers of oxidative stress in diabetic patients; however, their findings are controversial. The aim of the current meta-analysis was to evaluate the effects of probiotic and synbiotic supplementation on levels of serum high-sensitivity C-reactive protein (hs-CRP) and biomarkers of oxidative stress in diabetic patients. We searched the PubMed, Web of Science, and The Cochrane Library databases from the inception to October 31, 2018. Randomized controlled trials (RCTs) which reported the effect of probiotics or synbiotics on circulating (serum and plasma) inflammatory marker (hs-CRP) and oxidative stress indicators (malondialdehyde [MDA], glutathione [GSH], nitric oxide [NO], and total antioxidant capacity [TAC]) among patients with diabetes were included. Eligible studies were assessed for risk of bias and subjected to qualitative and quantitative synthesis using either fixed- or random-effects models accounting for clinical heterogeneity. Our meta-analysis identified 16 eligible RCTs (n = 1060). The methodological quality varied across these trials. Pooled data from these trials demonstrated that probiotic and synbiotic consumption significantly decreased hs-CRP level (standardized mean difference [SMD]=-0.38; 95% confidence interval [CI]:-0.51,-0.24; P = 0.000) and MDA (SMD=-0.61; 95% CI: -0.89, -0.32; P = 0.000) in diabetic patients compared to those in subjects receiving placebos. In addition, probiotic and symbiotic supplementation was found to increase TAC (SMD = 0.31; 95% CI: 0.09, 0.52; P = 0.006), NO (SMD, 0.62; 95% CI, 0.25 to 0.99; P = 0.001) and GSH (SMD = 0.41; 95% CI: 0.26, 0.55, P = 0.000) levels. The results of this systematic review and meta-analysis suggest that probiotic and synbiotic supplementation may help to improve biomarkers of inflammation and oxidative stress in diabetic patients. Further studies are needed to develop clinical practice guidelines for the management of inflammation and oxidative stress in these patients.

Rap1 Negatively Regulates the Hippo Pathway to Polarize Directional Protrusions in Collective Cell Migration.

In collective cell migration, directional protrusions orient cells in response to external cues, which requires coordinated polarity among the migrating cohort. However, the molecular mechanism has not been well defined. Drosophila border cells (BCs) migrate collectively and invade via the confined space between nurse cells, offering an in vivo model to examine how group polarity is organized. Here, we show that the front/back polarity of BCs requires Rap1, hyperactivation of which disrupts cluster polarity and induces misoriented protrusions and loss of asymmetry in the actin network. Conversely, hypoactive Rap1 causes fewer protrusions and cluster spinning during migration. A forward genetic screen revealed that downregulation of the Hippo (Hpo) pathway core components hpo or mats enhances the Rap1V12-induced migration defect and misdirected protrusions. Mechanistically, association of Rap1V12 with the kinase domain of Hpo suppresses its activity, which releases Hpo signaling-mediated suppression of F-actin elongation, promoting cellular protrusions in collective cell migration.

Current Sensor Fault Reconstruction for PMSM Drives.

This paper deals with a current sensor fault reconstruction algorithm for the torque closed-loop drive system of an interior PMSM. First, sensor faults are equated to actuator ones by a new introduced state variable. Then, in αß coordinates, based on the motor model with active flux linkage, a current observer is constructed with a specific sliding mode equivalent control methodology to eliminate the effects of unknown disturbances, and the phase current sensor faults are reconstructed by means of an adaptive method. Finally, an αß axis current fault processing module is designed based on the reconstructed value. The feasibility and effectiveness of the proposed method are verified by simulation and experimental tests on the RT-LAB platform.

Current Sensor Fault Diagnosis Based on a Sliding Mode Observer for PMSM Driven Systems.

This paper proposes a current sensor fault detection method based on a sliding mode observer for the torque closed-loop control system of interior permanent magnet synchronous motors. First, a sliding mode observer based on the extended flux linkage is built to simplify the motor model, which effectively eliminates the phenomenon of salient poles and the dependence on the direct axis inductance parameter, and can also be used for real-time calculation of feedback torque. Then a sliding mode current observer is constructed in αß coordinates to generate the fault residuals of the phase current sensors. The method can accurately identify abrupt gain faults and slow-variation offset faults in real time in faulty sensors, and the generated residuals of the designed fault detection system are not affected by the unknown input, the structure of the observer, and the theoretical derivation and the stability proof process are concise and simple. The RT-LAB real-time simulation is used to build a simulation model of the hardware in the loop. The simulation and experimental results demonstrate the feasibility and effectiveness of the proposed method.

Multiple diffraction data analysis for macromolecular crystals in stereoscopic multibeam imaging.

A detailed analysis of multiple diffraction data collected by the stereoscopic multibeam imaging technique from a tetragonal lysozyme crystal is reported. Calculations based on the dynamical theory are employed to account for diffraction profiles obtained with Bragg-angle scan in stereoscopic imaging and the conventional azimuthal scan in Renninger arrangement. The formation of a multibeam intensity profile and the relationship and mutual influence between the two scans are investigated. A simple practical method of quantitative estimation of the reflection phases of structure-factor multiplets from the experimental data obtained with two inversion-symmetry-related diffractions is proposed. The procedures for data handling and for distinguishing "partial" diffraction images from "full" diffraction images are also developed considering multibeam diffraction geometry and experimental conditions. These procedures thus provide a practical way of reconstructing diffraction profiles for experimental phase determination for macromolecular crystals.