Storage of plasma-derived exosomes: evaluation of anticoagulant use and preserving temperatures.

Exosomes carry large cargo of proteins, lipids, and nucleic acids, serving as versatile biomarkers for disease diagnosis and vehicles for drug delivery. However, up to date, no well recognized standard procedures for exosome storage were available for clinical application. This study aimed to determine the optimal storage conditions and the anticoagulants for plasma-derived exosome isolation. Fresh whole blood samples were collected from healthy participants and preserved in four different anticoagulants including sodium citrate (SC1/4), sodium citrate (SC1/9), lithium heparin (LH), or Ethylenediamine tetraacetic acid (EDTA), respectively. Exosomes were extracted from the plasma by differential ultracentrifugation and stored at three different temperatures, 4°C, -20°C or - 80°C for a duration ranging from one week to six months. All plasma samples for storage conditions comparison were pretreated with LH anticoagulant. Exosome features including morphological characteristics, pariticles size diameter, and surface protein profiles (TSG101, CD63, CD81, CD9, CALNEXIN) were assessed by transmission electron microscopy, Nanoparticle Tracking Analysis, and Western Blotting, respectively. Exosomes preserved in LH and SC1/4 group tended to remain intact microstructure with highly abundant protein biomarkers. Exosomes stored at 4°C for short time were prone to be more stable compared to thos at -80°C. Exosomes stored in plasma were superior in terms of ultrastructure, size diameter and surface protein expression to those stored in PBS. In conclusion, plasma-dervied exosome characteristics strictly depend on the anticoagulants and storage temperature and duration.

What is the context? Effective isolation of exosomes is a prerequisite for subsequent investigation into its involvemnt in disease development as well as potentialtherapeutic applications.Anticoagulants, storage temperature and durations might change the microscopical structure, integrity and also the stability of plasma-derived exosomes. However, no internationally recognized standard of exosome storage procedure was available for clinical use.What is new? Our finding evaluated the effect of anticoagulants and storage on plasma exosome characteristics.Exosomes isolated from plasma preserved with Li-heparin and sodium citrate (1/4) showed better physical properties and surface marker protein expression.Isolated exosomes appeared more stable in a short time for 4°C compared to −80°C. Storage of exosomes in plasma showed better physical properties and surface marker protein expression than in PBS.What is the impact? Our findings inform the significance of standardizing procedure of exosome isolation and preservation.

[Expression and diagnostic value of growth differentiation factor 15 in patients with septic cardiomyopathy].

OBJECTIVE: To explore the expression of growth differentiation factor 15 (GDF15) in patients with septic cardiomyopathy and its value in the diagnosis of septic cardiomyopathy. METHODS: A observational study was conducted. Fifty patients with septic cardiomyopathy admitted to Shanxi Bethune Hospital from May 2022 to March 2023 were selected as the experimental group. Forty-six patients with acute coronary syndrome (ACS) in the same period were selected as the case control group. Forty-nine healthy adults were selected as the healthy control group, who underwent physical examination in the physical examination center during the same period. The demographic data and clinical indicators of the subjects were recorded, and the serum GDF15 level was detected by double sandwich enzyme-linked immunosorbent assay (ELISA). And the 28-day outcome of patients with septic cardiomyopathy was followed up, and they were divided into survival group and death group. The serum GDF15 level of subjects in each group and its correlation with clinical indicators were analyzed and compared. Binary Logistic regression was used to analyze the risk factors of septic cardiomyopathy. Receiver operator characteristic curve (ROC curve) was used to evaluate the value of GDF15 in the diagnosis of septic cardiomyopathy. RESULTS: The serum GDF15 level of experimental group was significantly higher than that in the case control group and healthy control group [ng/L: 314.14 (221.96, 469.56) vs. 39.08 (26.27, 76.85), 6.39 (3.35, 14.42), both P < 0.01]. Correlation analysis showed that serum GDF15 level in patients with septic cardiomyopathy were correlated with cardiac troponin I (cTnI, r = 0.295, P = 0.038), brain natriuretic peptide (BNP, r = 0.464, P = 0.009), sequential organ failure assessment (SOFA, r = 0.363, P = 0.010) and acute physiology and chronic health evaluation II (APACHE II, r = 0.316, P = 0.025). However, there was no significant correlation with white blood cell count, neutrophil count, lymphocyte count, procalcitonin, C-reactive protein, lactic acid, albumin and other clinical indicators (r values were 0.086, 0.123, -0.051, 0.055, 0.119, 0.199, -0.234, all P > 0.05). Serum GDF15 level, SOFA score and APACHE II score in the death group (30 cases) were significantly higher than those in the survival group [20 cases; GDF15 (ng/L): 382.93±159.61 vs. 289.66±158.46, SOFA: 10.00 (7.00, 12.00) vs. 6.00 (5.00, 9.50), APACHE II: 21.70±6.07 vs. 14.85±7.57, all P < 0.05]. Binary Logistic regression analysis showed that serum GDF15 was an independent risk factor for the onset of septic cardiomyopathy [odds ratio (OR) = 1.062, 95% confidence interval (95%CI) was 1.011-1.115, P = 0.016]. ROC curve showed that the area under the curve (AUC) of GDF15 for predicting septic cardiomyopathy was 0.971, the specificity was 100%, and the sensitivity was 90.3%. CONCLUSIONS: The serum GDF15 level of patients with septic cardiomyopathy is significantly increased, and GDF15 may be used as an effective biomarker for the early diagnosis of septic cardiomyopathy.

Three-axis angle measurement method based on an optical wedge.

A three-axis angle measurement method is proposed using an optical wedge as a reflector. In this paper, the mathematical model of three-axis angle solving corresponding to the method is derived, and it is verified and corrected by establishing an optical simulation model, and, finally, the feasibility and measurement accuracy of the method are verified by using a principle prototype. The experimental results show that the RMS values of the measurement errors of pitch angle α, yaw angle ß, and roll angle γ are 6.27 ' ' , 4.35 ' ' , and 17.68 ' ' , respectively, within the measurement range of ±2∘, and the measurement accuracy is insensitive to the measurement distance.

An ultra-sensitive biosensor based on surface plasmon resonance and weak value amplification.

An ultra-sensitive phase plasmonic sensor combined with weak value amplification is proposed for the detection of IgG, as a model analyte. Phase detection is accomplished by self-interference between the p-polarization and the s-polarization of the light. With the principles of weak value amplification, a phase compensator is used to modulate the coupling strength and enhance the refractive index sensitivity of the system. On a simple Au-coated prism-coupled surface plasmon resonance (SPR) structure, the scheme, called WMSPR, achieves a refractive index sensitivity of 4.737 × 104 nm/RIU, which is about three times higher than that of the conventional phase-based approach. The proposed WMSPR biosensor gives great characteristics with a high resolution of 6.333 × 10-8 RIU and a low limit of detection (LOD) of 5.3 ng/mL. The results yield a great scope to promote the optimization of other SPR biosensors for high sensitivity.

Gene signatures to therapeutics: Assessing the potential of ivermectin against t(4;14) multiple myeloma.

BACKGROUND: Multiple myeloma (MM) is a terminal differentiated B-cell tumor disease characterized by clonal proliferation of malignant plasma cells and excessive levels of monoclonal immunoglobulins in the bone marrow. The translocation, (t)(4;14), results in high-risk MM with limited treatment alternatives. Thus, there is an urgent need for identification and validation of potential treatments for this MM subtype. Microarray data and sequencing information from public databases could offer opportunities for the discovery of new diagnostic or therapeutic targets. AIM: To elucidate the molecular basis and search for potential effective drugs of t(4;14) MM subtype by employing a comprehensive approach. METHODS: The transcriptional signature of t(4;14) MM was sourced from the Gene Expression Omnibus. Two datasets, GSE16558 and GSE116294, which included 17 and 15 t(4;14) MM bone marrow samples, and five and four normal bone marrow samples, respectively. After the differentially expressed genes were identified, the Cytohubba tool was used to screen for hub genes. Then, the hub genes were analyzed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. Using the STRING database and Cytoscape, protein-protein interaction networks and core targets were identified. Potential small-molecule drugs were identified and validated using the Connectivity Map database and molecular docking analysis, respectively. RESULTS: In this study, a total of 258 differentially expressed genes with enriched functions in cancer pathways, namely cytokine receptor interactions, nuclear factor (NF)-κB signaling pathway, lipid metabolism, atherosclerosis, and Hippo signaling pathway, were identified. Ten hub genes (cd45, vcam1, ccl3, cd56, app, cd48, btk, ccr2, cybb, and cxcl12) were identified. Nine drugs, including ivermectin, deforolimus, and isoliquiritigenin, were predicted by the Connectivity Map database to have potential therapeutic effects on t (4;14) MM. In molecular docking, ivermectin showed strong binding affinity to all 10 identified targets, especially cd45 and cybb. Ivermectin inhibited t(4;14) MM cell growth via the NF-κB pathway and induced MM cell apoptosis in vitro. Furthermore, ivermectin increased reactive oxygen species accumulation and altered the mitochondrial membrane potential in t(4;14) MM cells. CONCLUSION: Collectively, the findings offer valuable molecular insights for biomarker validation and potential drug development in t(4;14) MM diagnosis and treatment, with ivermectin emerging as a potential therapeutic alternative.

Uncovering the key factors influencing sustainable green production behavior among Chinese medicinal herb growers.

Promoting green production behavior among farmers is crucial for enhancing income, improving industrial efficiency, and ensuring ecological security. This study analyzes the determinants of green production behavior among farmers in Cheifeng, China, Using a binary logistic model on a sample of 860 microdata. The result of empirical analysis pointed out that the implementation rate of rural households was low at 54.5 %, highlighting the need for intervention. The results suggest that age, party members, total income, total area, irrigation conditions, market, policy, social factors, and knowledge transfer ability significantly influence green production behavior. Among these factors, age, party member, total area, irrigation conditions, and knowledge transfer ability have negative effects, while other factors positively affect green production. To promote green production behavior, this study recommends improving access to information, developing a training system, enhancing quality and safety information disclosure, establishing traceability mechanisms, and providing policy subsidies. This stud also highlights the need to strengthen publicity, technical guidance, and media persuasion for promoting the green production of Chinese medicinal materials.

Evaluating the Microheterogeneous Distribution of Photochemically Generated Singlet Oxygen Using Furfuryl Amine.

Singlet oxygen (1O2) is an important reactive species in natural waters produced during photolysis of dissolved organic matter (DOM). Prior studies have demonstrated that 1O2 exhibits a microheterogeneous distribution, with [1O2] in the interior of DOM macromolecules ∼30 to 1000-fold greater than in bulk solution. The [1O2] profile for DOM-containing solutions has been determined mainly by the use of hydrophobic probes, which are not commercially available. In this study, we employed a dual-probe method combining the widely used hydrophilic 1O2 probe furfuryl alcohol (FFA) and its structural analogue furfuryl amine (FFAm). FFAm exists mainly as a cation at pH <9 and was therefore hypothesized to have an enhanced local concentration in the near-DOM phase, whereas FFA will be distributed homogeneously. The probe pair was used to quantify apparent [1O2] in DOM samples from different isolation procedures (humic acid, fulvic acid, reverse osmosis) and diverse origins (aquatic and terrestrial) as a function of pH and ionic strength, and all samples studied exhibited enhanced reactivity of FFAm relative to FFA, especially at pH 7 and 8. To quantify the spatial distribution of [1O2], we combined electrostatic models with Latch and McNeill's three-phase distribution model. Modeling results for Suwannee River humic acid (SRHA) yield a surface [1O2] of ∼60 pM, which is ∼96-fold higher than the aqueous-phase [1O2] measured with FFA. This value is in agreement with prior reports that determined 1-3 orders of magnitude higher [1O2] in the DOM phase compared to bulk solution. Overall, this work expands the knowledge base of DOM microheterogeneous photochemistry by showing that diverse DOM isolates exhibit this phenomenon. In addition, the dual-probe approach and electrostatic modeling offer a new way to gain mechanistic insight into the spatial distribution of 1O2 and potentially other photochemically produced reactive intermediates.

Ultra-precise weak measurement-based interfacial biosensors.

In this study, an interfacial biosensing scheme with ultra-precision is proposed. The scheme uses weak measurement techniques to ensure ultra-high sensitivity of the sensing system while improving the stability of the system through self-referencing and pixel point averaging, thus achieving ultra-high detection accuracy of biological samples. In specific experiments, we have used the biosensor in this study to perform specific binding reaction experiments for protein A and Mouse IgG with a detection line of 2.71 ng/mL for IgG. In addition, the sensor is non-coated, simple in structure, easy to operate, and low in cost of use.

Corrigendum: RAB42 promotes glioma pathogenesis via the VEGF signaling pathway.

[This corrects the article DOI: 10.3389/fonc.2021.657029.].

Clinicopathological characteristics and prognostic significance of HDAC11 protein expression in non-small cell lung cancer: a retrospective study.

Background: Although the prognosis of non-small cell lung cancer (NSCLC) can be assessed based on pathological type, disease stage and inflammatory indicators, the prognostic scoring model of NSCLC still needs to improve. HDAC11 is associated with poor prognosis of partial tumors, but its prognostic relationship with NSCLC is poorly understood. In this study, the role of HDAC11 in NSCLC was studied to evaluate relationship with disease prognosis and potential therapeutic target. Methods: The clinicopathological and paracancerous tissues of patients with NSCLC primarily diagnosed in Tangdu Hospital from 2009 to 2013 were collected. Follow-up of patients were made every three months and the last follow-up period was December 2018. The expression of HDAC11 was assessed by immunohistochemistry (IHC). Then, weighted gene co-expression network analysis (WGCNA) was used to analyze the relationship between HDAC11 expression and the prognosis of lung adenocarcinoma (LUAD) patients. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Kaplan-Meier plotter database was used to verify the connection between hub genes and tumor stage and prognosis. We accessed the relationship between HDAC11 expression and clinicopathological features, and impact on the prognosis. Results: The study assessed 326 patients with NSCLC. Compared with adjacent tissues, HDAC11 expression was upregulated (HR =1.503, 95% CI: 1.172 to 1.927, P=0.001). Kaplan-Meier survival analyses showed that HDAC11 expression was closely related to OS of NSCLC patients (P=0.0011). Univariate and multivariate analyses showed that the independent risk factors of OS were clinical stage, HDAC11 expression, and HDAC11 differentiation (all P≤0.001). HDAC11 was significantly associated with prognosis in LUAD. A total of 1,174 differential genes and WGCNA were obtained to construct a co-expression network in LUAD. The GO and KEGG pathway enrichment analyses showed the relevance with staphylococcus aureus infection, NOD-like receptor signaling pathway, and others. The results of LUAD survival analysis showed that HDAC11-related genes NKX2-5 and FABP7 were significantly associated with LUAD prognosis. Conclusions: The high expression of HDAC11 is related to the poor prognosis of LUAD, and it is expected to become a therapeutic target and prognostic evaluation therapy for LUAD in the future. However, the relevant results need to be further studied and verified.

A fatal case of pneumonia and sepsis caused by sequence type 398 methicillin-susceptible Staphylococcus aureus carrying Pantone-Valentine leukocidin in China.

Staphylococcus aureus (S. aureus) sequence type 398 (ST398) has aroused great concern for its spread throughout the world. ST398 community-acquired MRSA (CA-MRSA) has been given greater emphasis because of its high virulence and high probability of treatment failure. Herein, A 22-year-old male was admitted to our hospital with a history of fever, chest pain and dyspnea for 2 days. A chest CT scan showed infiltrative and nodular shadows. The sequence type of the isolates from blood culture was ST398, the virulence genes detected was PVL gene (lukS-PV and lukF-PV). Despite resuscitation efforts, he died of multiple organ failure on admission 3rd day. This is the first described case of severe pneumonia and sepsis due to hematogenous spread of scalp furuncles caused by Panton-Valentine leukocidin (PVL) positive community-acquired methicillin-susceptible S. aureus (CA-MSSA) ST398 strains in an immunocompentent adult in mainland China. This report highlight the emergence CA-PVL-MSSA ST398 infection and its association with life-threatening infections. Early decolonization and identification of ST398 is critical. Severe skin and soft tissue infections should be suspected for ST398 PVL-MSSA.

Impact of Dairy Imports on Raw Milk Production Technology Progress in China.

China's dairy product import volume and output continue to grow rapidly, and to a certain extent, it will form a substitute for the Chinese dairy market. Therefore, it is necessary to study the impact of the import of dairy products on the technological progress of raw milk production in China. Using the data from 2005 to 2017, this paper uses the DEA model and the input-output model to analyze the impact of China's dairy product imports on the technological progress of raw milk production. The model results show that: (1) there are differences in the technological content of dairy products from different importing countries; (2) The total technological content of imported dairy products hinders the improvement of the technological progress index of small, medium and large-scale production of raw milk in China, and has the most prominent negative impact on the technological progress of large-scale raw milk production in China; (3) The technological content of dairy products imports from New Zealand, Australia, Germany, the Netherlands and other countries can help improve the technological progress index of China's moderate-scale production of raw milk, while importing countries from the United States, Canada and other countries hinder it.

Puerarin specifically disrupts osteoclast activation via blocking integrin-ß3 Pyk2/Src/Cbl signaling pathway.

OBJECTIVE: Given the limitations of current anti-resorption agents for postmenopausal osteoporosis, there is a need for alternatives without impairing coupling crosstalk between bone resorption and bone formation ie. osteoclastogenesis. Puerarin, a unique C-glycoside isoflavonoid, was found to be able to prevent bone loss by inhibiting bone resorption, but the underlying mechanism was controversial. In this study, we investigated the effects of puerarin on osteoclastic differentiation, activation and bone resorption and its underlying molecular mechanism in vitro, and then evaluated the effects of puerarin on bone metabolism using an ovariectomized (OVX) rat model. METHODS: In vitro, the effect of puerarin on osteoclastic cytotoxicity, differentiation, apoptosis, activation and function were studied in raw 264.7 â€‹cells and mouse BMMs. Mechanistically, osteoclast-related makers were determined by RT-PCR, western blot, immunofluorescence, and kinase activity assay. In vivo, Micro-CT, histology, serum bone biomarker, and mechanical testing were used to evaluate the effects of puerarin on preventing osteoporosis. RESULTS: Puerarin significantly inhibited osteoclast activation and bone resorption, without affecting osteoclastogenesis or apoptosis. In terms of mechanism, the expressions of protein of integrin-ß3 and phosphorylations of Src, Pyk2 and Cbl were lower in puerarin group than those in the control group. Oral administration of puerarin prevented OVX-induced trabecular bone loss and significantly improved bone strength in rats. Moreover, puerarin significantly decreased trap positive osteoclast numbers and serum TRAP-5b, CTx1, without affecting bone formation rate. CONCLUSIONS: Collectively, puerarin prevented the bone loss in OVX rat through suppression of osteoclast activation and bone resorption, by inhibiting integrin-ß3-Pyk2/Cbl/Src signaling pathway, without affecting osteoclasts formation or apoptosis. TRANSLATIONAL POTENTIAL OF THIS ARTICLE: These results demonstrate the unique mechanism of puerarin on bone metabolism and provide a novel agent for prevention of postmenopausal osteoporosis.

Cryptococcal Meningitis in a Patient with Sjogren's Syndrome: a Case Report.

BACKGROUND: Cryptococcal meningitis (CM) is a life-threatening infectious disease and causes high morbidity and mortality. No information about Cryptococcal meningitis in populations with Sjogren's syndrome (SS) was available. METHODS: This report details the first case of Cryptococcal meningitis in a 75-year-old female patient with 10-years history of Sjogren's syndrome. RESULTS: Detailed findings of C. neoformans from CSF examinations, including routine examination, India ink stain, immunological test, culturing, mass spectrum analysis and molecular biology identification were all delineated in this case, which facilitated understanding of detection methods in C. neoformans infection. The etiological exploration was initiated from a positive finding of yeast cells in routine examination of unstained CSF in the present case. Morphology description of C. neoformans in unstained CSF was depicted for the first time. CONCLUSIONS: Clinicians should consider the possible complication of Cryptococcal meningitis when patients with Sjogren's syndrome show neurological symptoms. Importance of screening yeast cells from unstained CSF for routine examination was emphasized, which may reduce errors in cell counting and trigger further etiological ex-ploration of C. neoformans infection in laboratory and clinical practice.

RAB42 Promotes Glioma Pathogenesis via the VEGF Signaling Pathway.

Angiogenesis plays an important role in tumor initiation and progression of glioma. Seeking for biomarkers associated with angiogenesis is important in enhancing our understanding of glioma biologically and identifying its new drug targets. RNA-sequencing (RNA-seq) data and matched clinical data were downloaded from the CGGA database. A series of filtering analyses were performed to screen for reliable genes: survival, multivariate Cox, ROC curve filtration, and clinical correlation analyses. After immunohistochemical verification, RAB42 was identified as a reliable gene for further single gene analysis. Afterwards, we performed gene set enrichment analysis (GSEA) and co-expression analysis to establish the related molecular mechanisms and signal pathways in glioma. Finally, the gene functions and the mechanisms were investigated in vitro experiments. A total of 23270 mRNA expression and 1018 glioma samples were included in this study. After the three filtering analyses, we selected ten genes for immunohistochemical verification: KLHDC8A, IKIP, HIST1H2BK, HIST1H2BJ, GNG5, FAM114A1, TMEM71, RAB42, CCDC18, and GAS2L3. Immunostaining demonstrated that RAB42 was significantly expressed on the membrane of glioma tissues but not in normal tissues. These results were verified and validated in GEPIA datasets, and the association between RAB42 with clinical features was also evaluated. Analysis of gene functions indicated that RAB42 activated VEGF signaling pathways and the mechanism was associated with natural killer cell mediated cytotoxicity, JAK-STAT signaling pathway and apoptosis pathways by PI3K/AKT in gliomas. Experiments in vitro suggested that the proliferation and invasion of glioma cells might be inhibited after downregulating of RAB42. And the tumorigenesis promotion of RAB42 may relate to the activation of VEGF signaling pathway. Taken together, this study shows that the overexpression of RAB42 is an independent prognostic factor of adverse prognosis. Its pro-oncogenic mechanism may be associated with the activation of VEGF signaling pathways.

Portfolio Seismic Loss Estimation and Risk-based Critical Scenarios for Residential Wooden Houses in Victoria, British Columbia, and Canada.

This study presents a city-wide seismic risk assessment of single-family wooden houses in Victoria, British Columbia, and Canada. The novelty and uniqueness of this study include considerations of detailed building-by-building exposure model for residential houses, current national seismic hazard model for Canada, and rigorous seismic fragility modeling of wooden houses based on nonlinear dynamic analysis of structures subjected to mainshock-aftershock sequences. A full consideration of stochastic event scenarios in probabilistic seismic risk analysis allows the identification of critical scenarios from overall regional seismic risk perspectives and provides valuable insights in informing earthquake disaster risk management actions. Outputs from the developed catastrophe model for Victoria are compared with the empirical model that was developed based on insurance claim data from the 1994 Northridge earthquake. Results of the seismic loss calculations highlight the importance of seismic resistance of the existing houses and of aftershock effects. The integrated use of the outputs from the advanced catastrophe model facilitates risk-based identification of critical earthquake scenarios, which are useful for different stakeholders for earthquake risk management purposes.

Resveratrol and Puerarin loaded polymeric nanoparticles to enhance the chemotherapeutic efficacy in spinal cord injury.

Spinal cord injury includes inflammation and apoptosis of neurons, which is difficult to cure by systemic drug administration. Administration of natural active compounds (resveratrol and also Puerarin) by advance drug delivery technology improves the patient's conditions. Oil-in-water emulsion method was utilized to prepare resveratrol as well as puerarin loaded PLGA nanoparticles. The nanoparticles were subjected to mean zeta potential, mean particle size, encapsulation efficiency as well as in vitro drug release studies. The biochemical parameters i.e. malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), advanced oxidation products (AOPP), catalase (CAT) and nitrite/nitrate levels were tested for the loaded nanoparticles. Reperfusion injury induced rats treated with 10 mg/kg resveratrol and puerarin loaded nanoparticles protects spine from ischemia injury and supports biological parameters. The mean particle size varies from 238 nm to 274 nm and also particle size distribution was mono-dispersed (0.239 to 0.318). Zeta potential value of nanoparticles was observed to be -12.6 ± 2.1 mV. Optimized nanoparticles reveals 72% -79% of drug release over 36 h by diffusion mechanism. Significantly, lowers the levels of plasma nitrite/nitrate level as well as phosphorylation of p38MAPK pathways in reperfusion injury induced rats. The resveratrol and puerarin loaded nanoparticles decreases free radicals produced by reperfusion injury induced rats, as well as decrease of oxidative stress because of IRI. Resveratrol and puerarin loaded nanoparticles decreases GSH, SOD and CAT antioxidant level, which helps in overall health improvement of patients.

Sequence-based protein structure optimization using enhanced simulated annealing algorithm on a coarse-grained model.

The understanding of protein structure is vital to determine biological function. We presented an enhanced simulated annealing (ESA) algorithm to investigate protein three-dimensional (3D) structure on a coarse-grained model. Inside the algorithm, we adjusted exploration equations to achieve good search intensity. To that end, our algorithm used (i) a multivariable disturbance operator for diversification of solution, (ii) a sign function to improve randomness of solution, and (iii) taking remainder operation performed on floating-point number to tackle out-of-range solution. By monitoring energy value throughout the simulation, the energy-optimal state can be found. The ESA algorithm was tested on artificial and real protein sequences with different lengths. The results show that our algorithm outperforms conventional simulated annealing algorithm and can compete with the reported algorithms before. Especially, our algorithm can obtain folding conformations with specific structural features. Further analysis shows that simulating trajectory of seeking the lowest energy can exhibit thermodynamic behavior of protein folding. Graphical Abstract.

Protein structure optimization using improved simulated annealing algorithm on a three-dimensional AB off-lattice model.

This paper proposed an improved simulated annealing (ISA) algorithm for protein structure optimization based on a three-dimensional AB off-lattice model. In the algorithm, we provided a general formula used for producing initial solution, and designed a multivariable disturbance term, relating to the parameters of simulated annealing and a tuned constant, to generate neighborhood solution. To avoid missing optimal solution, storage operation was performed in searching process. We applied the algorithm to test artificial protein sequences from literature and constructed a benchmark dataset consisting of 10 real protein sequences from the Protein Data Bank (PDB). Otherwise, we generated Cα space-filling model to represent protein folding conformation. The results indicate our algorithm outperforms the five methods before in searching lower energies of artificial protein sequences. In the testing on real proteins, our method can achieve the energy conformations with Cα-RMSD less than 3.0 Šfrom the PDB structures. Moreover, Cα space-filling model may simulate dynamic change of protein folding conformation at atomic level.

1.7 µm band narrow-linewidth tunable Raman fiber lasers pumped by spectrum-sliced amplified spontaneous emission.

A 1.7 µm band tunable narrow-linewidth Raman fiber laser based on spectrally sliced amplified spontaneous emission (SS-ASE) and multiple filter structures is proposed and experimentally demonstrated. In this scheme, an SS-ASE source is employed as a pump source in order to avoid stimulated Brillouin scattering. The ring configuration includes a 500 m long high nonlinear optical fiber and a 10 km long dispersion shifted fiber as the gain medium. A segment of un-pumped polarization-maintaining erbium-doped fiber is used to modify the shape of the spectrum. Furthermore, a nonlinear polarization rotation scheme is applied as the wavelength selector to generate lasers. A high-finesse ring filter and a ring filter are used to narrow the linewidth of the laser, respectively. We demonstrate tuning capabilities of a single laser over 28 nm between 1652 nm and 1680 nm by adjusting the polarization controller (PC) and tunable filter. The tunable laser has a 0.023 nm effective linewidth with the high-finesse ring filter. The stable multi-wavelength laser operation of up to four wavelengths can be obtained by adjusting the PC carefully when the pump power increases.