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Remote ischemic pre-conditioning (RIPC) protects against ischemia/reperfusion (I/R) injury. However, the mechanisms underlying this protection remain unclear. In the present study, we investigated the role of Janus-activated kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway and cell cycle arrest, and their relationship with neuronal apoptosis following RIPC.A rat cerebral I/R injury model was induced by middle cerebral artery occlusion (MCAO), and AG490 was used to investigate the mechanisms of RIPC. p-JAK2-, p-STAT3-, cyclin D1-, and cyclin-dependent kinase 6 (CDK6) expression was assessed by Western blotting and immunofluorescence staining.RIPC reduced the infarct volume, improved neurological function, and increased neuronal survival. Furthermore, p-JAK2 and p-STAT3 were detected during the initial phase of reperfusion; the expression levels were significantly increased at 3 and 24 h after reperfusion and were suppressed by RIPC. Additionally, the MCAO-induced upregulation of the cell cycle regulators cyclin D1 and CDK6 was ameliorated by RIPC. Meanwhile, cyclin D1 and CDK6 were colocalized with p-STAT3 in the ischemic brain.RIPC ameliorates the induction of the JAK2/STAT3 pathway and cell cycle regulators cyclin D1 and CDK6 by MCAO, and this net inhibition of cell cycle re-entry by RIPC is associated with downregulation of STAT3 phosphorylation.

Biochar provides an important pathway for the global response to climate change. The abiotic stability of biochar is important for its application in carbon capture and sequestration. To systematically illustrate the effects of pyrolysis temperature on composition, carbon fraction and abiotic stability of straw biochar, four kinds of straw biochars were prepared at pyrolysis temperatures of 300 °C, 400 °C, 500 °C, and 600 °C, respectively. The ultimate and proximate compositions, different carbon fractions and abiotic stability of prepared biochar were characterized, and their qualitative and quantitative relationships were established by Kendall correlation analysis, factor analysis and different regression analysis methods. Results showed that pyrolysis temperature influenced compositions and carbon fractions directly, which affected the abiotic stability of biochar (p R50), dissolution stability and chemical oxidation-resistant stability of biochar, all followed exponential functions with pyrolysis temperature. Unitary and binary linear regression equations among compositions, carbon fractions and the abiotic stability evaluation indicators were established. We hope that the results are scientifically valuable for a better understanding of the inherent properties of straw biochar, and thus help simplify the screening of appropriate indicators for evaluating the properties and abiotic stability of biochar. Graphical Abstract

Automatically generated static code warnings suffer from a large number of false alarms. Hence, developers only take action on a small percent of those warnings. To better predict which static code warnings should not be ignored, we suggest that analysts need to look deeper into their algorithms to find choices that better improve the particulars of their specific problem. Specifically, we show here that effective predictors of such warnings can be created by methods that locally adjust the decision boundary (between actionable warnings and others). These methods yield a new high water-mark for recognizing actionable static code warnings. For eight open-source Java projects (cassandra, jmeter, commons, lucene-solr, maven, ant, tomcat, derby) we achieve perfect test results on 4/8 datasets and, overall, a median AUC (area under the true negatives, true positives curve) of 92%., Accepted to TSE

The vertical volute centrifugal pump is widely used in the long-distance water division project. Flow separation and vortex phenomenon can be observed in the vaned diffuser under near stall operating conditions. This kind of unsteady flow structures would result in the instability of the pump unit which affect the safety and reliability of the unit operation. In this paper, the unsteady flow patterns and induced pressure fluctuation in a vertical volute centrifugal pump with vaned diffuser were simulated based on the SAS turbulence model and refined mesh under near stall conditions. The research results show that the SST turbulence model combined with the selected grid can be validated in the CFD uncertainty analysis during the steady calculation based on the ITTC relevant procedures. The performance results predicted by the SAS turbulence model show quite good agreement with the experimental data, and the prediction errors were less than 5%. The 3D flow matching between the flow angle at the impeller blade outlet and the incidence angle of the guide vane at different spans would induce the stall inception of the pump. The flow patterns of the pump under near stall conditions were revealed combined with vorticity and streamline distributions. When the pump unit was operated under near stall conditions, the main frequency changed from the blade passing frequency 7fn to 0.9fn. It was found that the main frequency was mainly affected by the large-scale vortices in the vaned diffuser, and the main vortices in the vaned diffuser appear at every 0.9 time of the period of one revolution of impeller.

Nitric oxide (NO) was one of the key factors to sustain hypoxia-inducible factor-1- α (HIF-1α) activation during hypoxia. However, the mechanism by which NO production promotes upregulation of HIF-1α to cause cerebral ischemia/reperfusion (I/R) injury remains unclear. The present study investigated whether eliminating NO would decrease HIF-1α level, and then reduce the subsequent inflammatory actions as well as neuronal apoptotic death in middle cerebral artery occlusion (MCAO) rats. Our results revealed that HIF-1α was correlated with 3-NT, a marker for nitrosative/oxidative stress, in the brain of MCAO rats. Treatment with NOS inhibitor L-NAME suppressed HIF-1α/3-NT double-positive cells, suggesting that HIF-1α was correlated with NO overproduction during cerebral I/R. Furthermore, pro-inflammatory cytokines TNF-α, IL-1β and NF-κB p65 were significantly increased and colocalized with HIF-1α in the brain of MCAO rats, all of which could be attenuated by NO inhibition, suggesting that eliminating NO reduced MCAO-induced HIF-1α upregulation, which in turn exerted anti-inflammatory actions. Accordingly, cleaved caspase-3, as well as HIF-1α and TUNEL double-positive cells in ischemic brain were also decreased by L-NAME treatment. These results suggest that NO accumulation after cerebral ischemia leads to HIF-1α upregulation, which may activate pro-inflammatory cytokines, resulting in neuronal apoptotic death. These findings demonstrate a novel mechanism of NO-induced cerebral I/R injury.

Background To further optimize the mechanochemical pretreatment process, a combined wet alkaline mechanical pretreatment of corn stover was proposed with a short time and less chemical consumption at room temperature. Results The combined alkaline mechanical pretreatment significantly enhanced enzymatic hydrolysis resulting a highest glucose yield (YG) of 91.9% with 3% NaOH and ball milling (BM) for 10 min. At this optimal condition, 44.4% lignin was removed and major portion of cellulose was retained (86.6%). The prehydrolysate contained by-products such as monosaccharides, oligosaccharides, acetic acid, and lignin but no furfural and 5-HMF. The alkaline concentration showed a significant impact on glucose yield, while the BM time was less important. Quantitative correlation analysis showed that YG (%) = 0.68 × BM time (min) + 19.27 × NaOH concentration (%) + 13.71 (R2 = 0.85), YG = 6.35 × glucan content − 231.84 (R2 = 0.84), and YG = − 14.22 × lignin content + 282.70 (R2 = 0.87). Conclusion The combined wet alkaline mechanical pretreatment at room temperature had a boosting effect on the yield of enzymatic hydrolysis with short treatment time and less chemical consumption. The impact of the physical and chemical properties of corn stover pretreated with different BM times and/or different NaOH concentrations on the subsequent enzymatic hydrolysis was investigated, which would be beneficial to illustrate the effective mechanism of the mechanochemical pretreatment method.

Nowadays, the effective credit scoring becomes a very crucial factor for gaining competitive advantages in credit market for both customers and corporations. In this paper, we propose a credit scoring method which combines the non-kernel fuzzy 2-norm quadratic surface SVM model, T-test feature weighting strategy and fuzzy within-class scatter together. It is worth pointing out that this new method not only saves computational time by avoiding choosing a kernel and corresponding parameters in the classical SVM models, but also addresses the "curse of dimensionality" issue and improves the robustness. Besides, we develop an efficient way to calculate the fuzzy membership of each training point by solving a linear programming problem. Finally, we conduct several numerical tests on two benchmark data sets of personal credit and one real-world data set of corporation credit. The numerical results strongly demonstrate that the proposed method outperforms eight state-of-the-art and commonly-used credit scoring methods in terms of accuracy and robustness.

We report here the use of a keyword-based and regular expression-based approach to identify bug-fixing commits by linking commit messages and issue tracker data in a recent FSE '20 paper by Penta et al. in their paper "On the Relationship between Refactoring Actions and Bugs: A Differentiated Replication". The approach replicated is a keyword-based and regular expression-based approach as studied by Fischer et al.

We report here the use of the static analysis dataset generated by FindBugs in a recent EMSE '21 paper by Yang et al. The artifact reproduced is supervised models to perform static analysis based on a golden feature set as studied by Wang et al.

In this paper, an optimization design of the vertical centrifugal pump with vaned diffuser was accomplished, and analyzed the internal flow pattern of the model before and after optimization under stall conditions to explore the relationship between design parameters and the stall characteristics. The reasons for the improvement of efficiency and hump characteristics curve after optimization were revealed combined with streamline distributions, entropy production theory and pressure fluctuation. The results show that the error between the external characteristic result calculated by Computational Fluid Dynamics (CFD) and the experimental value is less than 5%, which proves the reliability of the numerical simulation method adopted in this paper. The hydraulic efficiency under multiple operating conditions and stall characteristics of the optimized model have been significantly improved. After optimization, the entropy production rate in the vaned diffuser is greatly reduced, and the improvement of the internal flow pattern in the vaned diffuser is the main reason for slowing down the hump characteristic curve. The hydraulic performance and the stall characteristics of the vertical centrifugal pump can be significantly improved by properly increasing the radial distance of the vaneless region. The matching relationship between the vaned diffuser and the impeller is one of the important factors that affect the stall characteristics. The large-scale vortices in the vaned diffuser is the main reason for the low-frequency pressure fluctuation signal when operating in the hump region. The low-frequency signal in the vaned diffuser of the optimized model is obviously weakened.

In order to meet the requirements of high reliability and economy of space launch vehicle control system, a heterogeneous redundancy method of flight control computer based on mutual exclusion and spin mechanism is proposed in this paper. This method avoids common cause failure mode and improves hardware resource utilization efficiency by resolving redundancy. The reliability and economy of the launch vehicle control system can be improved without increasing the cost of volume and weight.

Ring-stiffened composite offshore rubber hose of single carcass is commonly used for offshore oil transfer. Common hose dimensions are length of 10.7 m and nominal diameter of 500 mm. The nominal burst pressure is 7.5 MPa, equal to five times rated working pressure of 1.5 MPa. The hose carcass is composite cylindrical tube made of rubber, reinforcing fiber cords and steel spiral stiffener that provides radial stiffness. In hose design, the burst pressure shall be determined to verify its pressure bearing capacity. In this paper, a nonlinear finite element hose model is created with commercial software ABAQUS and validated to predict its structural behavior under internal pressure. The large deformations, interactions between components and nonlinear material properties of hyperelastic rubber and fibers are considered. Stresses of stiffener, radial and axial deformation and load in reinforcement plies are obtained. A bulging phenomenon amid two stiffeners is found, which indicates the confine effect of stiffeners. Failure pressure is jointly determined by the strength limit of polymer cords and steel stiffener. The influence of different fibers and rubbers on hose pressure-deformation response are compared. The results demonstrate good accordance with requirement of specification. The finite element model can predict hose failure pressure and provide guidance for reliable hose design in practice.

Background Cutaneous intravascular NK/T cell lymphoma (CIVNKTC) is a rare form of extranodal non-Hodgkin's lymphoma with its unique histological and immunophenotypic characteristics. Methods We report a case presenting with an over 2-month history of nodules on the extremities and trunk with intermittent fever. Skin biopsy was taken from the patient and a histopathological examination was made from the material. Results The histopathological examination showed some expanding vessels filled with atypical lymphoid cells in the dermis and subcutaneous tissue. The tumor cells had large nuclei and one or two small nucleoli, with the expression of CD3, cytotoxic protein, and Epstein-Barr virus (EBV)-encoded messenger RNAs (EBER), and without the expression of tumor cytokeratin (CK), CD20, CD79A, CD4, and CD8. After being diagnosed as CIVNKTC and treated with a CHOP regimen 6 times, the patient died of this disease 1 year later. Conclusions The clinical course is dangerous and the prognosis is extremely poor.

With the development of deep-space exploration, electronic components and integrated circuits in the spacecraft must face the harsh environment in deep space, including cryogenic temperature. For CMOS devices, cryogenic temperature may cause issues in reliability. To qualify the normal application of CMOS devices, an evaluation method of CMOS devices at cryogenic temperature based on stress-strength interference theory was proposed. Moreover, according to the method, stress-strength interference models were built to calculate the failure probability of SN74AHC14 CMOS Inverters at cryogenic temperature.

Static code warning tools often generate warnings that programmers ignore. Such tools can be made more useful via data mining algorithms that select the "actionable" warnings; i.e. the warnings that are usually not ignored. In this paper, we look for actionable warnings within a sample of 5,675 actionable warnings seen in 31,058 static code warnings from FindBugs. We find that data mining algorithms can find actionable warnings with remarkable ease. Specifically, a range of data mining methods (deep learners, random forests, decision tree learners, and support vector machines) all achieved very good results (recalls and AUC (TRN, TPR) measures usually over 95% and false alarms usually under 5%). Given that all these learners succeeded so easily, it is appropriate to ask if there is something about this task that is inherently easy. We report that while our data sets have up to 58 raw features, those features can be approximated by less than two underlying dimensions. For such intrinsically simple data, many different kinds of learners can generate useful models with similar performance. Based on the above, we conclude that learning to recognize actionable static code warnings is easy, using a wide range of learning algorithms, since the underlying data is intrinsically simple. If we had to pick one particular learner for this task, we would suggest linear SVMs (since, at least in our sample, that learner ran relatively quickly and achieved the best median performance) and we would not recommend deep learning (since this data is intrinsically very simple)., 24 pages, 5 figures, 7 tables, accepted to Empirical Software Engineering and to appear

Photoperiod regulates the seasonal reproductive rhythms of mammals by influencing the development and function of sexual organs; however, the underlying mechanism remains unclear. We examined the morphology and functioning of the main sex organs of striped dwarf hamsters (Cricetulus barabensis) under different photoperiods (short daylight [SD], moderate daylight [MD], and long daylight [LD]) and further investigated the underlying molecular mechanisms. There was an inverse correlation between blood melatonin levels and photoperiod in the order SD > MD > LD. Decreases in body and tissue weights were observed under SD, whereas testis and epididymis weights between MD and LD were comparable. The diameters of the spermatogenic tubules, thickness of the spermatogenic epithelium, and the number of spermatogonia and Sertoli cells decreased under SD, whereas the serum-luteinizing hormone, follicle-stimulating hormone, and fecal testosterone concentrations decreased under LD. In SD, bax/bcl2 protein expression increased in the testes and decreased in the epididymides, whereas LC3II/LC3I remained unchanged in the testes and increased in the epididymides compared with the MD group. In LD, bax/bcl2 and LC3II/LC3I protein expression levels were unchanged in the testes but were decreased in the epididymides. In SD and LD, adenosine triphosphate synthase and citrate synthase protein expression levels were unchanged in the testes but were decreased in the epididymides. Drp1 and Mff protein expression increased in the testes and decreased in the epididymides. Overall, different regulatory mechanisms in the testis and epididymis led to degeneration under SD and maintenance under LD, preferentially protecting mitochondrial function in the testis by regulating mitochondrial fission.

The seventh oil layer of the Upper Triassic Yanchang Formation (Chang-7) tight oil sandstone reservoirs is a major exploration target. A significant amount of hydrocarbons has been discovered in these reservoirs in the southwestern Ordos basin in China. The Chang-7 tight sandstones are characterised as tight with low porosity, low permeability, and strong heterogeneity. This study investigates the sedimentary facies, diagenesis, and their impact on the reservoir quality of the Chang-7 tight oil sandstones. The sandstones were deposited in a deltaic-lacustrine depositional system. Three major depositional facies are identified consisting of delta front fed by braided rivers and meandering rivers, and slump turbidite fans. The depositional environment exerts a key control on reservoir quality. The distinct low-energy sedimentary environment produced fine to very fine-grained sandstones with high matrix and mica contents, characterised by low initial porosity and permeability. Diagenesis mainly comprised mechanical compaction and cementation by quartz, carbonate minerals and various clay minerals. The reservoir properties of the Chang-7 sandstones are generally poor, with porosity of 1.4–20.7% (average porosity 8.6%) and permeability of 0.001–116.7 mD (average 0.2 mD), which are attributed to significant compaction and cementation. Mechanical compaction was more important than cementation for reducing porosity, whereas secondary dissolution porosity was significant for the Chang-7 tight oil sandstones due to closer proximity to the underlying Chang-73 source rocks.

The Upper Triassic Chang-7 tight oil sandstones are the main tight clastic reservoirs in the Ordos Basin, central China. Illite is one of the most important cements affecting porosity and permeability of the tight oil sandstones, and this study focuses on different types of illitization and its relative formation time. The Chang-7 tight sandstones are mainly fine-grained lithic arkose and feldspar lithic sandstones, rich in mica and illite (hydrous mica). They are formed in distal delta front to semi-deep and deep lake facies, mainly deposited in a low energy environment. Porosity and permeability are very low (average porosity 8.58% and permeability 0.20 mD). The illite has many morphological characteristics and is multiphase, incorporating six types of illitization: hydrous mica, mica, and smectite illitization at the eodiagenetic stage, and kaolinite and K-feldspar illitization, and neoformation illite particles, at the mesodiagenetic stage. These different types of illitization are mainly controlled by sedimentary environment and provenance. Quartz overgrowth and diagenetic illites appear to be locally mutually exclusive, competing for detrital grain surfaces, but neoformation illite particles appear to form on the quartz overgrowth. The systematic study of Upper Triassic Chang-7 tight oil sandstones carried out here, enhances our understanding of illitization and the diagenetic model of the Ordos Basin, and contributes to reducing the exploration risk of continental tight sandstone reservoirs.

Electrospun PVA (polyvinyl alcohol)-LiCl composite membranes were prepared as novel solid desiccants. Experimental results show that nanofibrous membranes (NFMs) exhibit notable advantages in sorption capacity, sorption rate and low-temperature desorption rate, as compared with the solution-cast PVA-LiCl membranes (SCMs). The PVA NFM with 15 wt% LiCl can sorb 1.04 g g −1 water at 25 °C and 90% relative humidity (RH), which is more than twice of the reported capacity of silica gel. Due to the nano-structure and small diffusion distance, the desiccant membranes have fast sorption and desorption rates. The desorption isobars show that about 90% of the sorbed moisture can be removed at temperatures between 40 °C and 60 °C, which makes it promising to utilize solar energy or exhaust heat for air dehumidification. The composite desiccant membranes can also be recycled without the degradation of sorption and desorption performance.

A new polymer-based composite desiccant, Polyvinyl alcohol-LiCl nanofibrous membrane (PVA-LiCl NFM), has been prepared by the electrospinning technique. The newly-developed desiccant membrane not only has large moisture adsorption capacity, fast moisture adsorption rate and favorable stability, but also is featured by its low regeneration temperature. In this work, adsorption and desorption kinetic models are explored for PVA-LiCl NFMs, which include the pseudo-first and the pseudo-second order model based on the rate law and a diffusion model based on the Fick's law. The results indicate that the moisture adsorption and desorption kinetics of the PVA-LiCl NFMs follow the pseudo-second-order law very well. As the key parameters in the diffusion model, the equilibrium adsorption capacity and the diffusion coefficient are focused on, and they can be well determined by the Brunauer–Emmett–Teller (BET) model and the radial-basis-functions artificial neural network (RBFANN) model, respectively. Finally, the adsorption and desorption activation energy of the PVA-LiCl NFM with a 0.15 mass ratio of LiCl to PVA are recognized as 24.36 and 26.52 kJ/mol, respectively. The work is of great importance to the better application of the newly-developed desiccant material (PVA-LiCl NFM).

Herein, we analyzed the antibacterial effect of the TiO2 polymorphs and Ag3PO4/TiO2 heterojunctions. The sol-gel-derived TiO2 was calcined at 400 °C, 550 °C and 700 °C to get different polymorphs. Subsequently, Ag3PO4/TiO2 composites were synthesized by the in-situ precipitation method. These photocatalysts were characterized by XRD, TEM, UV–VIS–NIR, XPS, FP, AAS, and SEM. Photocatalytic sterilization was employed by the transferring and spreading tests with Gram-positive S. aureus (ATCC 25933) and Gram-negative E. coli (ATCC 25922) bacteria. It was noted that the anatase TiO2 has better antibacterial effect than rutile. And there was an existing synergetic effect between these two polymorphs. Besides partially preventing the photo corrosion, the Ag3PO4/TiO2 heterojunctions exhibit a remarkable bactericidal activity and almost completely collapse the high concentration bacterial cells. Moreover, The Ag3PO4/TiO2 heterojunctions show more pronounced in E. coli than S. aureus for their different cellular structure. The sterilization of the tolerant Gram-positive bacteria often needs the assistance of Ag-ion, while Gram-negative E. coli is more sensitive to •O2− radicals, and h+ during the photocatalytic sterilization.

Aiming at the aerodynamic optimization problem of guided ammunition airfoil, genetic algorithm is used to optimize the lift-drag ratio of the airfoil based CST geometric description method with given inflow velocity and fixed angle of attack. Firstly, the parameter space generated by CST parameterized airfoil description method is performed with binary code and the basic operations of genetic algorithm such as selection, crossover and mutation. Then, the external CFD solver is called to automatically divide the grid and calculate the lift-drag ratio through the control script. Finally, the target solution is obtained by searching. The calculation results show that this method can obtain a optimal target solution in relative less generation for a group of airfoils generated randomly in a certain search space.

Knowledge-based systems reason over some knowledge base. Hence, an important issue for such systems is how to acquire the knowledge needed for their inference. This paper assesses active learning methods for acquiring knowledge for "static code warnings". Static code analysis is a widely-used method for detecting bugs and security vulnerabilities in software systems. As software becomes more complex, analysis tools also report lists of increasingly complex warnings that developers need to address on a daily basis. Such static code analysis tools are usually over-cautious; i.e. they often offer many warnings about spurious issues. Previous research work shows that about 35% to 91% of warnings reported as bugs by SA tools are actually unactionable (i.e., warnings that would not be acted on by developers because they are falsely suggested as bugs). Experienced developers know which errors are important and which can be safely ignored. How can we capture that experience? This paper reports on an incremental AI tool that watches humans reading false alarm reports. Using an incremental support vector machine mechanism, this AI tool can quickly learn to distinguish spurious false alarms from more serious matters that deserve further attention. In this work, nine open-source projects are employed to evaluate our proposed model on the features extracted by previous researchers and identify the actionable warnings in a priority order given by our algorithm. We observe that our model can identify over 90% of actionable warnings when our methods tell humans to ignore 70 to 80% of the warnings., Comment: Accepted to Expert Systems with Applications

Blending perfluorosulfonic acid (e.g. Nafion) with other polymers is an effective approach to reduce the cost and adjust the properties of durable proton conducting membranes. In particular, poly(vinylidene fluoride) (PVDF) composites have attracted much attention because of its outstanding chemical/thermal stability and it can enhance the barrier property, mechanical strength and processibility of the membranes. One of the major issues with this approach, however, is that the proton conductivity of the Nafion/PVDF composite drops rapidly with increasing PVDF content. In this work, we demonstrate for the first time that through a simple and facile annealing process at 180 °C, the proton conductivity of the Nafion/PVDF blend membrane can be boosted by more than 200%, and the annealed membrane with 60 wt% Nafion shows proton conductivity as high as 45.2 mS cm−1. The barrier properties of the blend membranes are significantly superior to the neat Nafion as indicated by the vanadium ion permeability of approximately one third of the Nafion. In the single cell test of vanadium redox flow battery, the energy efficiency of the annealed membrane with 60 wt% Nafion reaches 83.6% at 100 mA cm−2, which is comparable to Nafion membranes. The annealed blend membranes possess a high chemical and dimensional stability, which makes them promising for practical applications in redox flow batteries or fuel cells.