Publications by authors named "Jun Geng"

36 Publications

Presacral Benign Schwannoma Mimics Malignancy on 18F-FDG and 68Ga-FAPI PET/CT.

Clin Nucl Med 2021 Oct 12. Epub 2021 Oct 12.

From the Department of Nuclear Medicine, The First People's Hospital of Neijiang, Neijiang Department of Nuclear Medicine, The Affiliated Hospital of Southwest Medical University Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province Academician (Expert) Workstation of Sichuan Province, Luzhou, Sichuan, China.

Abstract: We present findings of FDG PET/CT and FAPI PET/CT in a 55-year-old woman with a history of black stools and low-back pain. Pelvic CT detected a giant presacral mass that was suspected to be malignant. 18F-FDG and 68Ga-FAPI PET/CT showed that the mass had intense activity. Pathological examination confirmed the mass as a benign schwannoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLU.0000000000003933DOI Listing
October 2021

[Evaluation and Sources of Heavy Metal Pollution in the Surface Soil of the Qaidam Basin].

Huan Jing Ke Xue 2021 Oct;42(10):4880-4888

Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China.

To understand surface soil heavy metal pollution characteristics, and the spatial distribution and sources of pollution in the main sedimentary features of the Qaidam Basin, a total of 129 topsoil samples(0-10 cm) were collected within a 25 km radius. The concentrations of As, Ba, Cr, Mn, Nb, Ni, Pb, Ti, Zn, Zr, and ten kinds of heavy metals were determined, the degree of contamination and potential sources quantitatively analyzed based on enrichment factors(EFs), the ground accumulation index(), and the absolute principal component-multiple linear regression(APCS-MLR) receptor model. The results showed that the surface soils of the Qaidam Basin have experienced pollution from ten kinds of heavy metals since the 1960s, with varying degrees of enrichment. As and Pb represent probable point source pollutants, and the basin as a whole shows negligible to low levels of pollution. The APCS-MLR analysis showed that heavy metal pollution derives from two sources, natural factors and anthropogenic(transportation) sources. Specifically, As, Cr, Mn, Nb, Ni, Ti, Zn, and Zr are associated with natural sources, while Ba and Pb are associated with both natural and anthropogenic sources.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.13227/j.hjkx.202101052DOI Listing
October 2021

Performance of Regression Models as a Function of Experiment Noise.

Bioinform Biol Insights 2021 27;15:11779322211020315. Epub 2021 Jun 27.

Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.

Background: A challenge in developing machine learning regression models is that it is difficult to know whether maximal performance has been reached on the test dataset, or whether further model improvement is possible. In biology, this problem is particularly pronounced as sample labels (response variables) are typically obtained through experiments and therefore have experiment noise associated with them. Such label noise puts a fundamental limit to the metrics of performance attainable by regression models on the test dataset.

Results: We address this challenge by deriving an expected upper bound for the coefficient of determination ( ) for regression models when tested on the holdout dataset. This upper bound depends only on the noise associated with the response variable in a dataset as well as its variance. The upper bound estimate was validated via Monte Carlo simulations and then used as a tool to bootstrap performance of regression models trained on biological datasets, including protein sequence data, transcriptomic data, and genomic data.

Conclusions: The new method for estimating upper bounds for model performance on test data should aid researchers in developing ML regression models that reach their maximum potential. Although we study biological datasets in this work, the new upper bound estimates will hold true for regression models from any research field or application area where response variables have associated noise.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/11779322211020315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8243133PMC
June 2021

Formation free energy of an i-mer at spinodal.

J Chem Phys 2021 Jun;154(23):234108

Nuclear Engineering Department, Texas A&M University, 3133 TAMU, College Station, Texas 77843-3133, USA.

In statistical mechanics, the formation free energy of an i-mer can be understood as the Gibbs free energy change in a system consisting of pure monomers after and prior to the formation of the i-mer. For molecules interacting via Lennard-Jones potential, we have computed the formation free energy of a Stillinger i-mer [F. H. Stillinger, J. Chem. Phys. 38, 1486 (1963)] and a ten Wolde-Frenkel (tWF) [P. R. ten Wolde and D. Frenkel, J. Chem. Phys. 109, 9901 (1998)] i-mer at spinodal at reduced temperatures from 0.7 to 1.2. It turns out that the size of a critical Stillinger i-mer remains finite and its formation free energy is on the order of kT, and the size of a critical tWF i-mer remains finite and its formation free energy is even higher. This can be explained by Binder's theory [K. Binder, Phys. Rev. A 29, 341 (1984)] that for a system, when approaching spinodal, if the Ginzburg criterion is not satisfied, a gradual transition will take place from nucleation to spinodal decomposition, where the free-energy barrier height is on the order of kT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/5.0051879DOI Listing
June 2021

CODY enables quantitatively spatiotemporal predictions on in vivo gut microbial variability induced by diet intervention.

Proc Natl Acad Sci U S A 2021 03;118(13)

Department of Biology and Biological Engineering, Chalmers University of Technology, 412 96 Gothenburg, Sweden;

Microbial variations in the human gut are harbored in temporal and spatial heterogeneity, and quantitative prediction of spatiotemporal dynamic changes in the gut microbiota is imperative for development of tailored microbiome-directed therapeutics treatments, e.g. precision nutrition. Given the high-degree complexity of microbial variations, subject to the dynamic interactions among host, microbial, and environmental factors, identifying how microbiota colonize in the gut represents an important challenge. Here we present COmputing the DYnamics of microbiota (CODY), a multiscale framework that integrates species-level modeling of microbial dynamics and ecosystem-level interactions into a mathematical model that characterizes spatial-specific in vivo microbial residence in the colon as impacted by host physiology. The framework quantifies spatiotemporal resolution of microbial variations on species-level abundance profiles across site-specific colon regions and in feces, independent of a priori knowledge. We demonstrated the effectiveness of CODY using cross-sectional data from two longitudinal metagenomics studies-the microbiota development during early infancy and during short-term diet intervention of obese adults. For each cohort, CODY correctly predicts the microbial variations in response to diet intervention, as validated by available metagenomics and metabolomics data. Model simulations provide insight into the biogeographical heterogeneity among lumen, mucus, and feces, which provides insight into how host physical forces and spatial structure are shaping microbial structure and functionality.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.2019336118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8020746PMC
March 2021

Large Renal Cysts on Bone Scintigraphy in a Patient With Lower Back Pain.

Clin Nucl Med 2020 Feb;45(2):168-169

Department of Nuclear Medicine, Zigong First People's Hospital, Zigong, Sichuan, People's Republic of China.

Bone scintigraphy is often utilized to detect the osseous etiology of lower back pain. Here we report a 70-year-old man with lower back pain who was referred a Tc-MDP bone scan to identify possible vertebral compression fracture. The images did not detect any osseous lesion. However, the images revealed photopenic regions in the both kidneys, which were confirmed as renal cysts on the CT images. The patient received laparoscopic unroofing of renal cysts, and his symptoms improved. Our case illustrated that back pain is not always due to osseous etiology, it might be caused by urinary disorder.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLU.0000000000002867DOI Listing
February 2020

Formation free energies of clusters at high supersaturations.

J Chem Phys 2019 Oct;151(13):134111

Nuclear Engineering Department, Texas A&M University, 3133 TAMU, College Station, Texas 77843-3133, USA.

The Helmholtz free energy of a constrained supersaturated vapor with a cluster size distribution consisting of clusters of various sizes is modeled as a mixture of hard spheres of various sizes attracting each other. This model naturally takes into account monomer-monomer and monomer-cluster interactions, so it implicitly pertains to nonideal gases, unlike prior work. Based on this model, the expressions for the equilibrium concentration and the formation free energies of clusters in a metastable supersaturated vapor have been derived. These results indicate that the widely used formula, n = nexp(-βΔG), that computes the formation free energy of a cluster does not work at high supersaturations. As an example, the formation free energies of clusters with Stillinger's physical cluster definition in metastable, highly supersaturated vapors interacting via Lennard-Jones potential are studied using these expressions. Noticeable differences have been found for both the formation free energies of clusters and sizes of the critical clusters computed from our proposed expressions vs those from the formula n = nexp(-βΔG).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.5111943DOI Listing
October 2019

MiR-19a Promotes Migration And Invasion By Targeting RHOB In Osteosarcoma.

Onco Targets Ther 2019 23;12:7801-7808. Epub 2019 Sep 23.

Medical Laboratory Diagnosis Center, Jinan Central Hospital, Jinan 250013, People's Republic of China.

Introduction: Osteosarcoma is the most common bone tumor with high metastasis and recurrence rate. MicroRNA-19a (miR-19a) has been reported to act as tumor oncogene in multiple cancers. The objective of the study was to explore the molecular mechanisms of miR-19a in osteosarcoma cell migration and invasion.

Materials And Methods: Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blotting were employed to measure the levels of miR-19a and RhoB in osteosarcoma tissues and cell lines. Transwell assay was employed to analyze the tissues and cell lines' migratory and invasive abilities. Dual luciferase reporter assay was utilized to analyze the association between miR-19a and RhoB.

Results: MiR-19a was overexpressed in osteosarcoma tissues and cell lines. MiR-19a promoted osteosarcoma cell migration and invasion in vitro. RhoB was thus confirmed as a direct and functional target of miR-19a, and it could partially reverse the function of miR-19a. Knockdown miR-19a inhibited osteosarcoma cell epithelial-mesenchymal transition (EMT) and suppressed osteosarcoma xenograft growth.

Conclusion: MiR-19a enhanced cell migration, invasion and EMT through RhoB in osteosarcoma. The newly identified miR-19a/RhoB axis provides novel insight into the progression of osteosarcoma and offers a promising target for osteosarcoma therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/OTT.S218047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6765345PMC
September 2019

Acetaldehyde Dehydrogenase 2 rs671 Polymorphism Affects Hypertension Susceptibility and Lipid Profiles in a Chinese Population.

DNA Cell Biol 2019 Sep 30;38(9):962-968. Epub 2019 Jul 30.

Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong University, Jinan, P.R. China.

Previous studies revealed that the rs671 polymorphism in the acetaldehyde dehydrogenase 2 () genes is correlated with alcohol consumption in Japanese population. The gene variants and drinking are associated with hypertension and dyslipidemia. However, it remains unclear whether there might be potent relationships among rs671 polymorphism, alcohol consumption, hypertension, and dyslipidemia in Shandong population. A total of 467 male volunteers from Shandong area were enrolled in this study. The rs671 polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism. The concentrations of total cholesterol (TC), triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) in serum were measured using commercial kits. SPSS 23.0 was used for statistical analysis. The significance of differences between subgroups was determined using chi-square test, and multiple comparisons were performed with the least-significant difference method. The variant frequencies were 80.5% with GG, 17.1% with GA, and 2.4% with AA. The genotypes had significant correlations with alcohol consumption ( = 0.001), whereas the GA genotype was associated with a decreased risk of alcohol consumption (odds ratio = 0.27; 95% confidence interval = 0.130-0.539;  = 0.001). The genotypes frequencies and drinking habits were significantly different between hypertension and healthy individuals ( = 0.034;  = 0.044). The GG genotype individuals have high average lipids levels, and the proportion of TC disorder among GG individuals was higher than that of GA individuals ( = 0.006). Individuals who had drinking habits have a high average lipids levels; especially average TC levels ( = 0.048), and had high proportions of dyslipidemia (TC and HDL;  = 0.016 and  = 0.033, respectively). The frequencies of variants were evaluated according to the Hardy-Weinberg equilibrium among enrolled population. Our study suggested that the individuals with rs671 GA genotype were less prone to developing a drinking habit in Shandong population. The genotypes and drinking habit were associated with hypertension and lipid profiles especially TC profile in Shandong province. The rs671 genotypes indicated that the gene-related drinking habit and gene variant altogether may affect hypertension and dyslipidemia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/dna.2019.4647DOI Listing
September 2019

Influence of propofol intravenous anesthesia on hemorheology, haemodynamics and immune function of colorectal carcinoma patients undergoing radical resection.

Pak J Med Sci 2019 ;35(3):780-785

Jun Geng, Inpatient Operating Rooms II, Binzhou People's Hospital, Shandong, 256610, China.

Objective: To analyze the changes of hemorheology, haemodynamics and immune function of patients during propofol intravenous anesthesia in the radical resection of colorectal carcinoma and its significance.

Methods: The study included 112 patients who underwent radical resection of colorectal carcinoma in our hospital between August 2016 and December 2017, and they were divided into an observation group (N=56) and a control group (N=56) using random number table. Patients in the observation group were given propofol intravenous anesthesia, while patients in the control group received inhalation anesthesia of sevoflurane. Hemorheological and haemodynamical indexes were compared and analyzed before anesthesia (T0), 90 min after induction (T1), 150 min after induction (T2) and 30 min after entering post-anesthesia care unit (T3), and the changes of immune function before and after surgery was also observed.

Results: The whole blood viscosity under high, medium and low shear rates of the observation group declined significantly compared to that of the control group at T1, T2 and T3 (P<0.05). The heart rate (HR) and systolic pressure (SPB) of the observation group significantly decreased at T2 compared to those at T1 (P<0.05), but recovered to the level observed at T0 at T3. The diastolic blood pressure (DBP) of the two groups at T1, T2 and T3 was not significantly different with that at T0 (P>0.05). The levels of CD45RA+ and CD45RO+ of both groups had a significant decrease at the end of the surgery compared to before anesthesia (P<0.05); the levels of the observation group recovered at the postoperative 72 h, and the differences with the levels before anesthesia had no statistical significance (P>0.05); the level of CD45RA+ of the control group also recovered at the postoperative 72 h, but the difference with the level before anesthesia had no statistical significance (P>0.05); the level of CD45RO+ of the control group had a significant decrease, and the difference with the level before anesthesia was statistically significant (P<0.05). The level of CD45RA+/CD45RO+ of the observation group at the end of surgery and the postoperative 72 h was not significantly different with those before anesthesia (P>0.05). The level of CD45RA+/CD45RO+ of the control group at the postoperative 72 h showed a significant increase compared to before anesthesia (P<0.05).

Conclusion: Propofol intravenous anesthesia has a significant improvement effect on hemorheology before radical resection of colorectal carcinoma and has a small influence on haemodynamics. Moreover it is beneficial to the recovery of immune function. The therapy is worth promotion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12669/pjms.35.3.590DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6572957PMC
January 2019

Postoperative analgesia with ropivacaine and dexmedetomidine for ultrasound-guided fascia iliaca compartment block after arthroscopic knee surgery.

Saudi J Anaesth 2019 Apr-Jun;13(2):100-105

Department of Anesthesiology, Jiangyin Hospital, Affiliated to Southeast University Medical School, Jiangyin, China.

Objective: The objective of this study is to evaluate the postoperative analgesic effect of a combination of ropivacaine and dexmedetomidine for ultrasound-guided fascia iliaca compartment block (FICB) after knee arthroscopy.

Materials And Methods: Forty patients scheduled for knee arthroscopy were randomized to receive either 30 ml of 0.25% ropivacaine alone (Group A, = 20) or combined with dexmedetomidine 1 μg/kg (Group B, = 20). Pain intensity was evaluated using the visual analogue scale (VAS), at rest and during activity at 4, 6, 8, 12, and 24 h after surgery. Level of consciousness was evaluated using the Ramsay sedation score. Time to first analgesic request after surgery, the dose of analgesic used in the first 24 h after surgery, variation of heart rate, and adverse reactions were also recorded.

Results: VAS scores at 6 and 12 h after surgery were significantly lower in Group B compared to Group A ( < 0.05). No significant difference was observed in the Ramsay sedation score or time to first analgesic request after surgery ( > 0.05). The total dose of analgesic used in the first 24 h after surgery was higher in Group A than in Group B. The incidence of bradycardia was higher in Group B compared to Group A. No adverse reactions were observed in either group.

Conclusion: FICB with a combination of ropivacaine and dexmedetomidine resulted in significant reduction of VAS scores with lower postoperative analgesic requirement after arthroscopic knee surgery. No adverse reactions or complications were noted except for lower heart rate in Group B patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/sja.SJA_533_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6448445PMC
April 2019

The protective effect of kaempferol on heart via the regulation of Nrf2, NF-κβ, and PI3K/Akt/GSK-3β signaling pathways in isoproterenol-induced heart failure in diabetic rats.

Drug Dev Res 2019 05 12;80(3):294-309. Epub 2019 Mar 12.

Medical Research and Laboratory Diagnostic Center, Jinan Central Hospital Affiliated to Shandong University, Jinan, People's Republic of China.

This study was designed to delineate the effect of kaempferol (KF) on heart failure (HF) in diabetic rats. Streptozotocin-induced male diabetic rats received KF orally at 10 and 20 mg/kg for 42 consecutive days. In last 2 days of the experimental period, isoproterenol was subcutaneously injected at 85 mg/kg to induce HF. The hearts were processed for hemodynamic, biochemical, molecular, and histological investigations. Systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were elevated in KF-treated HF-induced diabetic rats. Moreover, KF treatment resulted in decreased fasting blood glucose and glycosylated hemoglobin levels with increased serum insulin levels. Besides, serum cardiac injury markers like troponin-I, creatine kinase-muscle/brain, lactate dehydrogenase, and brain natriuretic peptide levels were significantly reduced in KF treatment. KF treatment has shown decrease in cardiac heme oxygenase-1, nuclear factor erythroid 2-related factor 2 (Nrf-2), and γ-glutamylcysteine synthetase with increased Keap1 mRNA levels. The cardioprotection of KF was improved by inhibition of apoptosis via blocking phosphorylation of Akt/glycogen synthase kinase (GSK)-3β and p38 mitogen-activated protein-kinase/extracellular signal-regulated kinases signaling pathways in HF-induced diabetic rats. Moreover, reduced cardiac apoptosis in KF treatment was confirmed by decreased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) positive cells, histopathological changes in HF-induced diabetic rats. Therefore, the cardioprotective effect of KF is attributed to the regulation of Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells, and Akt/GSK-3β signaling pathways in HF-induced diabetic rats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/ddr.21495DOI Listing
May 2019

Thermal physiological performance of two freshwater turtles acclimated to different temperatures.

J Comp Physiol B 2019 02 27;189(1):121-130. Epub 2018 Nov 27.

Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, 310036, Zhejiang, People's Republic of China.

The thermal physiological performance of invasive species may play a crucial role in determining their invasion success. In this study, we acclimated two cohorts of hatchlings of freshwater turtles (native Mauremys reevesii and invasive Trachemys scripta elegans) from low and high-latitude collection sites, respectively, to different thermal conditions (20 and 30 °C) for 4 weeks, and then compared their thermal tolerance and locomotor performance. T. scripta elegans hatchlings could swim faster (but righted themselves more slowly), and tolerate a higher temperature and wider temperature range than M. reevesii hatchlings. Similarly, T. scripta elegans hatchlings had a greater maximal performance (P) value for swimming speed (but a lower P value for righting time) than M. reevesii hatchlings. Temperature acclimation had a significant impact on the thermal tolerance and locomotor ability of turtles, but the acclimation effect did not differ between the two species. T. scripta elegans hatchlings seemed to have a greater thermal plasticity than M. reevesii hatchlings. High-latitude individuals showed a greater low-temperature tolerance, but lower locomotor ability (longer righting time) than low-latitude ones. However, the thermal plasticity did not differ between latitudinal cohorts. Our results indicated that T. scripta elegans performed better than M. reevesii, which might contribute to its range expansion and invasive success.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00360-018-1194-xDOI Listing
February 2019

Combination of anginex gene therapy and radiation decelerates the growth and pulmonary metastasis of human osteosarcoma xenografts.

Cancer Med 2018 06 16;7(6):2518-2529. Epub 2018 Apr 16.

Jinan Central Hospital Affiliated to Shandong University, No. 105, Jiefang Road, Jinan, 250013, Shandong, China.

Investigate whether rAAV-anginex gene therapy combined with radiotherapy could decrease growth and pulmonary metastasis of osteosarcoma in mice and examine the mechanisms involved in this therapeutic strategy. During in vitro experiment, multiple treatment regimes (rAAV-eGFP, radiotherapy, rAAV-anginex, combination therapy) were applied to determine effects on proliferation of endothelial cells (ECs) and G-292 osteosarcoma cells. During in vivo analysis, the same multiple treatment regimes were applied to osteosarcoma tumor-bearing mice. Use microcomputed tomography to evaluate tumor size. Eight weeks after tumor cell inoculation, immunohistochemistry was used to assess the therapeutic efficacy according to microvessel density (MVD), proliferating cell nuclear antigen (PCNA), and terminal-deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) assays. Metastasis of lungs was also evaluated by measuring number of metastatic nodules and wet weight of metastases. The proliferation of ECs and the tumor volumes in combination therapy group were inhibited more effectively than the other three groups at end point (P < 0.05). Cell clone assay showed anginex had radiosensitization effect on ECs. Immunohistochemistry showed tumors from mice treated with combination therapy exhibited the lowest MVD and proliferation rate, with highest apoptosis rate, as confirmed by IHC staining for CD34 and PCNA and TUNEL assays (P < 0.05). Combination therapy also induced the fewest metastatic nodules and lowest wet weights of the lungs (P < 0.05). rAAV-anginex combined with radiotherapy induced apoptosis of osteosarcoma cells and inhibited tumor growth and pulmonary metastasis on the experimental osteosarcoma models. We conclude that the primary mechanism of this process may be due to sensitizing effect of anginex to radiotherapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cam4.1476DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6010866PMC
June 2018

The clinical benefits of perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery: a meta-analysis.

Interact Cardiovasc Thorac Surg 2017 12;25(6):966-974

Jiangsu Province's Key Medical Center for Cardiovascular Surgery, Suzhou, Jiangsu, China.

The clinical benefits of perioperative antioxidant vitamin therapy in cardiac patients remain controversial. Here, we conducted a meta-analysis to determine the strength of the evidence supporting the perioperative use of antioxidant vitamins in patients undergoing cardiac surgery. We searched 4 databases (PubMed, EMBASE, Science Citation Index and Cochrane Library) for randomized controlled trials that reported the effects of antioxidant vitamin therapy on patients undergoing cardiac surgery until 6 June 2016. Risk ratio (RR) or mean difference (MD) and its 95% confidence interval (95% CI) served as the summarized results. Heterogeneity among included studies was evaluated using the I2 statistic, which help determine which effect model to apply. We constructed a funnel plot to assess the existence of publication bias. Sensitivity analyses were also conducted to evaluate the robustness of the outcomes. Twelve trials with 1584 cardiac patients were included. Compared with placebo or no antioxidant vitamin therapy, administration of antioxidant vitamin therapy resulted in a reduction in postoperative atrial fibrillation (POAF) (RR 0.55, 95% CI 0.42, 0.73, P < 0.0001), duration of hospital stay (MD -0.68, 95% CI -0.98, -0.39, P < 0.00001), intensive care unit length of stay (MD -0.21, 95% CI -0.30, -0.12, P < 0.00001) and intubation time (MD -2.41, 95% CI -3.83, -0.98, P = 0.001). Our results also showed a trend towards a decrease in postoperative complications (RR 0.72, 95% CI 0.48, 1.08, P = 0.11) and duration of POAF (MD -1.950, 95% CI -3.28, 0.29, P = 0.10). This meta-analysis demonstrated that perioperative antioxidant vitamin therapy in patients undergoing cardiac surgery can reduce the incidence of POAF, duration of hospital stay, intensive care unit length of stay and intubation time.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/icvts/ivx178DOI Listing
December 2017

Quickest Sequential Multiband Spectrum Sensing with Mixed Observations.

IEEE Trans Signal Process 2016 Nov 24;64(22):5861-5874. Epub 2016 Aug 24.

Department of Electrical and Computer Engineering, University of California, Davis, CA, 95616, USA ( ).

Spectrum sensing is a key technology enabling the cognitive radio system. In this paper, the problem of how to quickly and accurately find an unoccupied channel from a large amount of potential channels is considered. The cognitive radio system under consideration is equipped with a narrow band sensor, hence it can only sense those potential channels in a sequential manner. In this scenario, we propose a novel two-stage mixed-observation sensing strategy. In the first stage, which is named as scanning stage, the sensor observes a linear combination of the signals from a pair of channels. The purpose of the scanning stage is to quickly identify a pair of channels such that at least one of them is highly likely to be unoccupied. In the second stage, which is called refinement stage, the sensor only observers the signal from one of those two channels identified from the first stage, and selects one of them as the unoccupied channel. The problem under this setup is an ordered two concatenated Markov stopping time problem. The optimal solution is solved using the tools from the multiple stopping time theory. It turns out that the optimal solution has a rather complex structure, hence a low complexity algorithm is proposed to facilitate the implementation. In the proposed low complexity algorithm, the cumulative sum test is adopted in the scanning stage and the sequential probability ratio test is adopted in the refinement stage. The performance of this low complexity algorithm is analyzed when the presence of unoccupied channels is rare. Numerical simulation results show that the proposed sensing strategy can significantly reduce the sensing time when the majority of potential channels are occupied.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1109/TSP.2016.2602802DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5292203PMC
November 2016

The free energy of the metastable supersaturated vapor via restricted ensemble simulations. III. An extension to the Corti and Debenedetti subcell constraint algorithm.

J Chem Phys 2016 Apr;144(14):144503

Nuclear Engineering Department, Texas A&M University, 3133 TAMU, College Station, Texas 77843-3133, USA.

In order to improve the sampling of restricted microstates in our previous work [C. Nie, J. Geng, and W. H. Marlow, J. Chem. Phys. 127, 154505 (2007); 128, 234310 (2008)] and quantitatively predict thermal properties of supersaturated vapors, an extension is made to the Corti and Debenedetti subcell constraint algorithm [D. S. Corti and P. Debenedetti, Chem. Eng. Sci. 49, 2717 (1994)], which restricts the maximum allowed local density at any point in a simulation box. The maximum allowed local density at a point in a simulation box is defined by the maximum number of particles Nm allowed to appear inside a sphere of radius R, with this point as the center of the sphere. Both Nm and R serve as extra thermodynamic variables for maintaining a certain degree of spatial homogeneity in a supersaturated system. In a restricted canonical ensemble, at a given temperature and an overall density, series of local minima on the Helmholtz free energy surface F(Nm, R) are found subject to different (Nm, R) pairs. The true equilibrium metastable state is identified through the analysis of the formation free energies of Stillinger clusters of various sizes obtained from these restricted states. The simulation results of a supersaturated Lennard-Jones vapor at reduced temperature 0.7 including the vapor pressure isotherm, formation free energies of critical nuclei, and chemical potential differences are presented and analyzed. In addition, with slight modifications, the current algorithm can be applied to computing thermal properties of superheated liquids.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.4945723DOI Listing
April 2016

The Influence of Perioperative Dexmedetomidine on Patients Undergoing Cardiac Surgery: A Meta-Analysis.

PLoS One 2016 6;11(4):e0152829. Epub 2016 Apr 6.

Department of Anesthesiology and Pain Medicine, University of California Davis Health System, Sacramento, California, United States of America.

Background: The use of dexmedetomidine may have benefits on the clinical outcomes of cardiac surgery. We conducted a meta-analysis comparing the postoperative complications in patients undergoing cardiac surgery with dexmedetomidine versus other perioperative medications to determine the influence of perioperative dexmedetomidine on cardiac surgery patients.

Methods: Randomized or quasi-randomized controlled trials comparing outcomes in patients who underwent cardiac surgery with dexmedetomidine, another medication, or a placebo were retrieved from EMBASE, PubMed, the Cochrane Library, and Science Citation Index.

Results: A total of 1702 patients in 14 studies met the selection criteria among 1,535 studies that fit the research strategy. Compared to other medications, dexmedetomidine has combined risk ratios of 0.28 (95% confidence interval [CI] 0.15, 0.55, P = 0.0002) for ventricular tachycardia, 0.35 (95% CI 0.20, 0.62, P = 0.0004) for postoperative delirium, 0.76 (95% CI 0.55, 1.06, P = 0.11) for atrial fibrillation, 1.08 (95% CI 0.74, 1.57, P = 0.69) for hypotension, and 2.23 (95% CI 1.36, 3.67, P = 0.001) for bradycardia. In addition, dexmedetomidine may reduce the length of intensive care unit (ICU) and hospital stay.

Conclusions: This meta-analysis revealed that the perioperative use of dexmedetomidine in patients undergoing cardiac surgery can reduce the risk of postoperative ventricular tachycardia and delirium, but may increase the risk of bradycardia. The estimates showed a decreased risk of atrial fibrillation, shorter length of ICU stay and hospitalization, and increased risk of hypotension with dexmedetomidine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0152829PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4822865PMC
August 2016

The Extraction Model of Paddy Rice Information Based on GF-1 Satellite WFV Images.

Guang Pu Xue Yu Guang Pu Fen Xi 2015 Nov;35(11):3255-61

In the present, using the characteristics of paddy rice at different phenophase to identify it by remote sensing images is an efficient way in the information extraction. According to the remarkably properties of paddy rice different from other vegetation, which the surface of paddy fields is with a large number of water in the early stage, NDWI (normalized difference water index) which is used to extract water information can reasonably be applied in the extraction of paddy rice at the early stage of the growth. And using NDWI ratio of two phenophase can expand the difference between paddy rice and other surface features, which is an important part for the extraction of paddy rice with high accuracy. Then using the variation of NDVI (normalized differential vegetation index) in different phenophase can further enhance accuracy of paddy rice information extraction. This study finds that making full advantage of the particularity of paddy rice in different phenophase and combining two indices (NDWI and NDVI) associated with paddy rice can establish a reasonable, accurate and effective extraction model of paddy rice. This is also the main way to improve the accuracy of paddy rice extraction. The present paper takes Lai'an in Anhui Province as the research area, and rice as the research object. It constructs the extraction model of paddy rice information using NDVI and NDWI between tillering stage and heading stage. Then the model was applied to GF1-WFV remote sensing image on July 12, 2013 and August 30, 2013. And it effectively extracted out of paddy rice distribution in Lai'an and carried on the mapping. At last, the result of extraction was verified and evaluated combined with field investigation data in the study area. The result shows that using the extraction model can quickly and accurately obtain the distribution of rice information, and it has the very good universality.
View Article and Find Full Text PDF

Download full-text PDF

Source
November 2015

Thermal preference, thermal resistance, and metabolic rate of juvenile Chinese pond turtles Mauremys reevesii acclimated to different temperatures.

J Therm Biol 2015 Oct 25;53:119-24. Epub 2015 Sep 25.

Hangzhou Key Laboratory for Animal Adaptation and Evolution, School of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China. Electronic address:

The thermal acclimatory capacity of a particular species may determine its resilience to environmental change. Evaluating the physiological acclimatory responses of economically important species is useful for determining their optimal culture conditions. Here, juvenile Chinese three-keeled pond turtles (Mauremys reevesii) were acclimated to one of three different temperatures (17, 25 or 33°C) for four weeks to assess the effects of thermal acclimation on some physiological traits. Thermal acclimation significantly affected thermal resistance, but not thermal preference, of juvenile M. reevesii. Turtles acclimated to 17°C were less resistant to high temperatures than those acclimated to 25°C and 33°C. However, turtles increased resistance to low temperatures with decreasing acclimation temperature. The acclimation response ratio of the critical thermal minimum (CTMin) was lower than that of the critical thermal maximum (CTMax) for acclimation temperatures between 17 and 25°C, but slightly higher between 25 and 33°C. The thermal resistance range (i.e., the difference between CTMax and CTMin) was widest in turtles acclimated to the intermediate temperature (25°C), and narrowest in those acclimated to low temperature (17°C). The standard metabolic rate increased as body temperature and acclimation temperature increased, and the temperature quotient (Q10) between acclimation temperatures 17 and 25°C was higher than the Q10 between 25 and 33°C. Our results suggest that juvenile M. reevesii may have a greater resistance under mild thermal conditions resembling natural environments, and better physiological performance at relatively warm temperatures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jtherbio.2015.09.003DOI Listing
October 2015

Morphology transition in lipid vesicles due to in-plane order and topological defects.

Proc Natl Acad Sci U S A 2013 Feb 11;110(9):3242-7. Epub 2013 Feb 11.

Physics Department, University of California, Merced, CA 95343, USA.

Complex morphologies in lipid membranes typically arise due to chemical heterogeneity, but in the tilted gel phase, complex shapes can form spontaneously even in a membrane containing only a single lipid component. We explore this phenomenon via experiments and coarse-grained simulations on giant unilamellar vesicles of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine. When cooled from the untilted L(α) liquid-crystalline phase into the tilted gel phase, vesicles deform from smooth spheres to disordered, highly crumpled shapes. We propose that this shape evolution is driven by nucleation of complex membrane microstructure with topological defects in the tilt orientation that induce nonuniform membrane curvature. Coarse-grained simulations demonstrate this mechanism and show that kinetic competition between curvature change and defect motion can trap vesicles in deeply metastable, defect-rich structures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1213994110DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3587188PMC
February 2013

Deformation of an asymmetric thin film.

Phys Rev E Stat Nonlin Soft Matter Phys 2012 Sep 12;86(3 Pt 2):036602. Epub 2012 Sep 12.

Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA.

Experiments have investigated shape changes of polymer films induced by asymmetric swelling by a chemical vapor. Inspired by recent work on the shaping of elastic sheets by non-Euclidean metrics [Y. Klein, E. Efrati, and E. Sharon, Science 315, 1116 (2007)], we represent the effect of chemical vapors by a change in the target metric tensor. In this problem, unlike that earlier work, the target metric is asymmetric between the two sides of the film. Changing this metric induces a curvature of the film, which may curve into a partial cylinder or a partial sphere. We calculate the elastic energy for each of these shapes and show that the sphere is favored for films smaller than a critical size, which depends on the film thickness, while the cylinder is favored for larger films.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevE.86.036602DOI Listing
September 2012

On enhancing productivity of bioethanol with multiple species.

Biotechnol Bioeng 2012 Jun 7;109(6):1508-17. Epub 2012 Jan 7.

School of Chemical Engineering, Purdue University, West Lafayette, Indiana, USA.

The present work is initiated to investigate whether a defined culture comprising a mixture of three yeast species, Kluyveromyces marxianus, Saccharomyces cerevisiae, and Pichia stipitis can ferment a mixture of sugars to produce bioethanol at rates higher than those achieved by pure cultures of the same. For this purpose, we develop models of single species based on the hybrid cybernetic model framework, and simulate fermentations in the mixed culture by combining individual models. An underlying assumption is that the behavior of each species is determined only by the common environment independently of the presence and metabolism of other species. Model performance is thoroughly assessed using the experimental data available in the literature. The dynamic behavior of mixed cultures in mixed culture experiments are accurately predicted by the model reflecting faithfully the simultaneous/sequential uptake patterns of mixed substrates. This model is then used to investigate performance of various possible reactor configurations. With the foregoing species of organisms, mixed culture itself does not lead to a significant increase of bioethanol productivity. Rather, the model shows that substantial improvement is acquired by sequential use of different, properly chosen organisms during fermentation. Thus, the successive use of K. marxianus and P. stipitis is shown to increase bioethanol productivity up to about 58% in comparison to fermentation by single species alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/bit.24419DOI Listing
June 2012

Manganese-doped ZnSe quantum dots as a probe for time-resolved fluorescence detection of 5-fluorouracil.

Anal Chem 2011 Dec 9;83(23):9076-81. Epub 2011 Nov 9.

State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.

Quantum dots (QDs) are generally used for the conventional fluorescence detection. However, it is difficult for the QDs to be applied in time-resolved fluorometry due to their short-lived emission. In this paper, high-quality Mn-doped ZnSe QDs with long-lived emission were prepared using a green and rapid microwave-assisted synthetic approach in aqueous solution. Fluorescence lifetime of the Mn-doped ZnSe QDs was extended as long as 400 μs, which was 10,000 times higher than that of conventional QDs such as CdS, CdSe, and CdTe. The QDs exhibited an excellent photostability over 35 h under continuous irradiation at 260 nm. Capped with mercaptopropionic acid (MPA), the Mn-doped ZnSe QDs were used for the time-resolved fluorescence detection of 5-fluorouracil (5-FU) with the detection limit of 128 nM. The relative standard deviation for seven independent measurements of 1.5 μM 5-FU was 3.8%, and the recovery ranged from 93% to 106%. The results revealed that the Mn-doped ZnSe QDs could be a good candidate as a luminescence probe for highly sensitive time-resolved fluorometry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/ac202101uDOI Listing
December 2011

Theory and simulation of two-dimensional nematic and tetratic phases.

Phys Rev E Stat Nonlin Soft Matter Phys 2009 Jul 23;80(1 Pt 1):011707. Epub 2009 Jul 23.

Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA.

Recent experiments and simulations have shown that two-dimensional systems can form tetratic phases with fourfold rotational symmetry, even if they are composed of particles with only twofold symmetry. To understand this effect, we propose a model for the statistical mechanics of particles with almost fourfold symmetry, which is weakly broken down to twofold. We introduce a coefficient kappa to characterize the symmetry breaking, and find that the tetratic phase can still exist even up to a substantial value of kappa. Through a Landau expansion of the free energy, we calculate the mean-field phase diagram, which is similar to the result of a previous hard-particle excluded-volume model. To verify our mean-field calculation, we develop a Monte Carlo simulation of spins on a triangular lattice. The results of the simulation agree very well with the Landau theory.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevE.80.011707DOI Listing
July 2009

Cybernetic modeling based on pathway analysis for Penicillium chrysogenum fed-batch fermentation.

Bioprocess Biosyst Eng 2010 Aug 19;33(6):665-74. Epub 2009 Jun 19.

Department of Automation, Shanghai Jiao Tong University, 800 Dongchuan Road, 200240, Shanghai, People's Republic of China.

A macrokinetic model employing cybernetic methodology is proposed to describe mycelium growth and penicillin production. Based on the primordial and complete metabolic network of Penicillium chrysogenum found in the literature, the modeling procedure is guided by metabolic flux analysis and cybernetic modeling framework. The abstracted cybernetic model describes the transients of the consumption rates of the substrates, the assimilation rates of intermediates, the biomass growth rate, as well as the penicillin formation rate. Combined with the bioreactor model, these reaction rates are linked with the most important state variables, i.e., mycelium, substrate and product concentrations. Simplex method is used to estimate the sensitive parameters of the model. Finally, validation of the model is carried out with 20 batches of industrial-scale penicillin cultivation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00449-009-0340-yDOI Listing
August 2010

Synthesis and electrogenerated chemiluminescence of PbS nanospheres.

J Nanosci Nanotechnol 2009 Apr;9(4):2387-91

Key Laboratory of Analytical Chemistry for Life Science (MOE), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.

The uniform PbS nanospheres with an average diameter of 110 nm were synthesized via a sonochemical approach using PVP as a template reagent in aqueous solution. The chemiluminescence of the as-prepared PbS induced by electrochemical method was investigated. Stable electrogenerated chemiluminescence was first observed from the PbS nanospheres in the existence of peroxodisulfate ions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1166/jnn.2009.se46DOI Listing
April 2009

The free energy of the metastable supersaturated vapor via restricted ensemble simulations. II. Effects of constraints and comparison with molecular dynamics simulations.

J Chem Phys 2008 Jun;128(23):234310

School of Physics and Information Engineering, Jianghan University, Wuhan 430056, People's Republic of China.

Extensive restricted canonical ensemble Monte Carlo simulations [D. S. Corti and P. Debenedetti, Chem. Eng. Sci. 49, 2717 (1994)] were performed. Pressure, excess chemical potential, and excess free energy with respect to ideal gas data were obtained at different densities of the supersaturated Lennard-Jones (LJ) vapor at reduced temperatures from 0.7 to 1.0. Among different constraints imposed on the system studied, the one with the local minimum of the excess free energy was taken to be the approximated equilibrium state of the metastable LJ vapor. Also, a comparison of our results with molecular dynamic simulations [A. Linhart et al., J. Chem. Phys. 122, 144506 (2005)] was made.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2937893DOI Listing
June 2008

Study of thermal properties of the metastable supersaturated vapor with the integral equation method.

J Chem Phys 2008 Feb;128(5):054305

School of Physics and Information Engineering, Jianghan University, Wuhan 430056, People's Republic of China.

Pressure, excess chemical potential, and excess free energy data for different densities of the supersaturated argon vapor at reduced temperatures from 0.7 to 1.2 are obtained by solving the integral equation with perturbation correction to the radial distribution function [F. Lado, Phys. Rev. 135, A1013 (1964)]. For those state points where there is no solution, the integral equation is solved with the interaction between argon atoms modeled by Lennard-Jones potential plus a repulsive potential with one controlling parameter, alpha exp(-rsigma) and in the end, all the thermal properties are mapped back to the alpha=0 case. Our pressure data and the spinodal obtained from the current method are compared with a molecular dynamics simulation study [A. Linhart et al., J. Chem. Phys. 122, 144506 (2005)] of the same system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2831328DOI Listing
February 2008

The free energy of the metastable supersaturated vapor via restricted ensemble simulations.

J Chem Phys 2007 Oct;127(15):154505

School of Physics and Information Engineering, Jianghan University, Wuhan, People's Republic of China 430056.

Pressure, excess chemical potential, and excess free energy, with respect to ideal gas data at different densities of the supersaturated Lennard-Jones particle vapor at the reduced temperature 0.7 are obtained by the restricted canonical ensemble Monte Carlo simulation method [D. S. Corti and P. Debenedetti, Chem. Eng. Sci. 49, 2717 (1994)]. The excess free energy values depend upon the constraints imposed on the system with local minima exhibited for densities below the spinodal density and monotonic variation for densities larger than the spinodal density. The results are compared with a molecular dynamics simulation study [A. Linharton et al., J. Chem. Phys. 122, 144506 (2005)] on the same system. The current study verifies the conclusion drawn by the simulation work that clustering of Lennard-Jones atoms exists even in the vicinity of spinodal. Our method gives an alternative to molecular dynamic simulations for the determination of equilibrium properties of a metastable fluid, especially close to the spinodal, and does not require a very large system to carry out the simulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1063/1.2794752DOI Listing
October 2007
-->