Based on the Split Hopkinson Pressure Bar (SHPB) system, dynamic compressive tests were done on red-sandstone specimens, which were free from freeze-thaw (F-T) or suffered from 5, 10, 15, 25 F-T ...cycles. Stress–strain curves and energy evolution curves of specimens were analyzed as well as the dynamic mechanical properties and energy indexes. The results indicated that red-sandstone suffered a lot from the F-T weathering, with both the dynamic uniaxial compression strength and elastic modulus reduced with the adding-up of F-T cycles. Stress–strain curves of F-T weathered red-sandstone can be broadly divided into four stages, and the energy evolution characteristics of them differed from each other. Energy dissipation ratio was put forward to appraise the energy dissipation and damage accumulation degree during the four deformation stages, and the total input energy and dissipated energy were adopt to describe the F-T-mechanical coupling damage evolution properties during deformation and failure process of red-sandstone after freeze-thaw cycles and under impact loading. F-T influenced not only the initial damage values of red-sandstone, but also the damage evolution rules during the loading process. With the adding-up of F-T cycles, growth quantity of damage factor before the peak point reduced. Strain rate also affected the damage evolution rules clearly, and with the increase of strain rate, the damage factor grew more slowly.
•Impact tests are applied on sandstone free from or after freeze–thaw (F-T) cycles.•Dynamic stress–strain curves and energy evolution curves of rock suffered from F-T.•Damage analyses based on energy dissipation ratio of each stage during failure process.•F-T-mechanical coupling damage is defined based on input energy and dissipated energy.•Damage evolution during the dynamic compression failure process of F-T weathered rock.
The coupling effects of chemical corrosion and freeze-thaw (F-T) cycling on the compressive failure characteristics of yellow sandstone were investigated. Results show that both chemical corrosion ...and minimum temperature in F-T cycles have adverse effect on the mechanical properties of yellow sandstone. With decreasing minimum F-T temperature and pH of the corrosive solution, peak stress and elastic modulus both decrease while peak strain increases, illustrating that the bearing capacity and deformation resistant capacity both decrease while ductility increases. During UCS tests, less damaged samples with a lower porosity tend to exhibit double-cone failure and contain smaller pores and more trans-grain fractures. Higher-damage samples with higher porosity tend to exhibit split failure or slope failure and contain larger pores and more inter-grain fractures. Chemical reactions between yellow sandstone and various chemical solutions are analyzed. F-T damage primarily occurs during freezing while chemical corrosion primarily occurs during thawing. Additionally, both the friction state and the internal microstructural damage influence the final failure mode. Results of this work can provide reference for the construction and development of rock structures in cold regions.
•The coupled effect of chemical corrosion and F-T cycling on sandstone are studied.•Possible chemical reactions are analyzed to explain this coupling effect.•Failure modes of UCS tests are from three basic patterns or their combinations.•SEM is adopted to analyze the micro-structure of the samples.•Internal micro-structures and frictional states both affect the final failure modes.
Abstract The response of cardiac fibroblast proliferation to detrimental stimuli is one of the main pathological factors causing heart remodeling. Reactive oxygen species (ROS) mediate the ...proliferation of cardiac fibroblasts. However, the exact molecular mechanism remains unclear. In vivo, we examined the oxidative modification of miRNAs with miRNA immunoprecipitation with O 8 G in animal models of cardiac fibrosis induced by Ang II injection or ischemia‒reperfusion injury. Furthermore, in vitro, we constructed oxidation-modified miR-30c and investigated its effects on the proliferation of cardiac fibroblasts. Additionally, luciferase reporter assays were used to identify the target of oxidized miR-30c. We found that miR-30c oxidation was modified by Ang II and PDGF treatment and mediated by excess ROS. We demonstrated that oxidative modification of G to O 8 G occurred at positions 4 and 5 of the 5′ end of miR-30c (4,5-oxo-miR-30c), and this modification promoted cardiac fibroblast proliferation. Furthermore, CDKN2C is a negative regulator of cardiac fibroblast proliferation. 4,5-oxo-miR-30c misrecognizes CDKN2C mRNA, resulting in a reduction in protein expression. Oxidized miR-30c promotes cardiac fibroblast proliferation by mismatch mRNA of CDKN2C.
•Approximately 15% of the patients with schizophrenia had recent SI.•Patients with SI had significantly higher PRL levels than those without SI.•SI severity was significantly associated with serum ...levels of PRL, TG and RBANS visuospatial skill subscore.
Patients with schizophrenia have a high risk for suicide, and therefore, identification of risk factors for suicidal ideation (SI) may be helpful to reduce suicide rate. This study aimed to detect which clinical symptoms and biochemical parameters were most strongly associated with SI. A total of 174 patients and 35 healthy controls were enrolled in our study. Patients were evaluated by the Positive and Negative Syndrome Scale (PANSS), Scale of Assessment Negative Symptoms (SANS) and the Calgary Depression Scale for Schizophrenia (CDSS) for psychiatric and depressive symptoms, and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) for cognitive function. We examined the levels of prolactin (PRL) and metabolic parameters in all participants. Our results showed a significantly increased level of PRL in patients compared to the controls before (t = 10.414, P < 0.001) and after (F = 31.308, P < 0.001) covariates were controlled for. In addition, we found that patients with SI had significantly higher PRL levels than those without SI (t = 2.586, P = 0.011). And there were positive correlations between serum PRL levels (r = 0.194, P = 0.010), serum fasting triglyceride levels (TG) (r = 0.188, P = 0.013), and RBANS visuospatial skill subscores (r = 0.162, P = 0.036) and SI severity. Finally, the stepwise multiple linear regression analysis revealed that SI severity was significantly associated with PRL levels, fasting TG levels and RBANS visuospatial skill subscores. This study provides support that greater cognitive ability, specifically visuospatial skill, PRL and TG, may confer an elevated risk for more severe SI in schizophrenia patients.
The aims of this study were to (1) evaluate the efficacy and safety of targeted antibiotics for the treatment of culture-negative prosthetic joint infection based on metagenomic next-generation ...sequencing results and (2) verify the accuracy and reliability of metagenomic next-generation sequencing for identifying pathogens related to culture-negative prosthetic joint infection.
Ninety-seven consecutive PJI patients, including 27 patients with culture-negative prosthetic joint infection, were treated surgically at our center. Thirteen of the 27 culture-negative prosthetic joint infection patients, who were admitted before June 2017 and treated with empirical antibiotics, comprised the empirical antibiotic group (EA group), and the other 14 patients, who were admitted after June 2017 and treated with targeted antibiotics according to their metagenomic next-generation sequencing results, were classified as the targeted antibiotic group (TA group). The short-term infection control rate, incidence of antibiotic-related complications and costs were compared between the two groups.
Two of the patients in the EA group experienced debridement and prolonged antimicrobial therapy due to wound infection after the initial revision surgery. No recurrent infections were observed in the TA group; however, no significant difference in the infection control rate was found between the two groups (83.33% vs 100%, P = 0.217). More cases of antibiotic-related complications were recorded in the EA group (6 cases) than in the TA group (1 case), but the difference was not statistically significant (P = 0.0697). The cost of antibiotics obtained for the EA group was 20,168.37 Yuan (3236.38-45,297.16), which was higher than that found for the TA group (10,164.16 Yuan, 2959.54-16,661.04, P = 0.04).
Targeted antibiotic treatment for culture-negative prosthetic joint infection based on metagenomic next-generation sequencing results is associated with a favorable outcome, and metagenomic next-generation sequencing is a reliable tool for identifying pathogens related to culture-negative prosthetic joint infection.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Negative symptoms and cognitive impairments in schizophrenia patients are associated with the patients' functional outcomes and quality of life. However, pharmacotherapy has little effect on such ...symptoms. This study aimed to systematically evaluate the efficacy of transcranial direct current stimulation (tDCS) in ameliorating negative symptoms and cognitive impairments in schizophrenia patients.
A literature search was performed in the PubMed, Embase, PsycINFO and Cochrane Library databases through March 23, 2020. Studies were included if they met all the following criteria: (1) subjects were exclusively patients with schizophrenia, schizoaffective disorder or psychosis, (2) active tDCS and shame stimulation were conducted in two parallel groups, (3) sufficient data were present, and (4) the study design was based on a randomized controlled trial. Two authors conducted the search strategy, publication assessment and data extraction independently, and a third person was consulted when any disagreement emerged.
A total of 14 studies were included (12 studies included negative symptoms and 7 studies included cognitive impairments). The overall meta-analysis showed no significant difference between active and sham tDCS in ameliorating negative symptoms in schizophrenia patients (SMD: −0.14, 95% CI: −0.33– 0.05). Subgroup analysis including studies with a high stimulation frequency, twice daily, revealed a significant difference in therapeutic effects between active tDCS and sham stimulation (SMD: −0.31, 95% CI: −0.58 to −0.05). With respect to cognitive impairments, there was a trend indicating that active tDCS might improve cognitive impairment (SMD: −0.21, 95% CI: −0.46– 0.04), but the overall meta-analysis failed to obtain statistically significant results.
Our meta-analysis indicates that tDCS is a potential strategy for improving negative symptoms, but the therapeutic benefit for negative symptoms requires a high stimulation frequency (twice a day).
•mNGS is superior to standard culture in the PJI diagnosis and improve pathogen detection rate;•mNGS can improve diagnosis of co-colonization, which can lead to improved treatment strategy and ...improved clinical outcome;•mNGS of periprosthetic tissue can potentially replace analyses of synovial fluid or sonication fluid.
The purpose of this study was to explore the role of mNGS in the diagnosis of PJI by detecting the presence of bacteria in periprosthetic tissues.
Patients who were suspected of PJI and underwent surgery in our center were enrolled. Microbial culture and mNGS were performed on periprosthetic tissues collected intraoperatively. Patient age, body mass index (BMI), laboratory tests, microbial culture and mNGS results were recorded. The diagnostic performance of microbial culture and mNGS in the diagnosis of PJI was compared.
A total of 44 patients were included. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of periprosthetic tissue microbial culture in the diagnosis of PJI were 72.72%, 77.27%, 76.19%, 73.91% and 75%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of periprosthetic tissue mNGS in the diagnosis of PJI were 95.45%, 90.91%, 91.3%, 95.24% and 93.18%, respectively. The sensitivity and specificity of mNGS in the diagnosis of PJI were superior to those of microbial culture.
Periprosthetic tissue can be used as an alternative to synovial fluid and sonication fluid, as mNGS can improve the diagnosis of PJI. mNGS of the periprosthetic tissues showed higher sensitivity than microbial culture.
Suicide risk is greatly increased in depression. Detection of those at risk is clinically important. Hence, this study aimed to evaluate the prevalence and identify independent risk factors ...associated with suicidal ideation (SI) in a widespread symptomatology within and outside DSM framework.
This study was part of the National Survey on Symptomatology of Depression (NSSD) which was designed to investigate the magnitude of symptoms of current major depressive episode in China. Stepwise multivariable logistic regression was performed to examine the independent risk factors for SI, including variables that are statistically significant in univariate analysis. Receiver operating characteristic (ROC) was used to evaluate the performance of the regression model.
A total of 3275 patients (1293 males and 1982 females) were included in our analysis. Of these, 1750 patients (53.4%) had SI. Independent risk predictors included crying (P = 0.000; odds ratio = 1.827), helplessness (P = 0.000; odds ratio = 1.514), worthlessness (P = 0.001; odds ratio = 1.359), hopelessness (P = 0.000; odds ratio = 1.805), unusually restless (P = 0.005; odds ratio = 1.276), self-harm (P = 0.000; odds ratio = 3.385), mood-incongruent psychosis (P = 0.000; odds ratio = 2.782), feeling losing control of oneself (P = 0.009; odds ratio = 1.352), hypersomnia (P = 0.000; odds ratio = 1.805), sensory system complaints (P = 0.000; odds ratio = 1.546), derealization (P = 0.006; odds ratio = 1.580), guilt (P = 0.002; odds ratio = 1.332), suicidal attempts (P = 0.000; odds ratio = 2.841), male gender (P = 0.001; odds ratio = 0.756), the total course of depression (P = 0.010; odds ratio = 1.003) in the regression model. In addition, the areas under the curve of the ROC and the accuracy for the regression model were 0.80 and 0.76, respectively.
This study provided an effective risk model for SI in MDD and indicated that all these factors in our model allow better the employment of preventative measures.
Infectious diarrhea can lead to a considerable global disease burden. Thus, the accurate prediction of an infectious diarrhea epidemic is crucial for public health authorities. This study was aimed ...at developing an optimal random forest (RF) model, considering meteorological factors used to predict an incidence of infectious diarrhea in Jiangsu Province, China.
An RF model was developed and compared with classical autoregressive integrated moving average (ARIMA)/X models. Morbidity and meteorological data from 2012 to 2016 were used to construct the models and the data from 2017 were used for testing.
The RF model considered atmospheric pressure, precipitation, relative humidity, and their lagged terms, as well as 1-4 week lag morbidity and time variable as the predictors. Meanwhile, a univariate model ARIMA (1,0,1)(1,0,0)
(AIC = - 575.92, BIC = - 558.14) and a multivariable model ARIMAX (1,0,1)(1,0,0)
with 0-1 week lag precipitation (AIC = - 578.58, BIC = - 578.13) were developed as benchmarks. The RF model outperformed the ARIMA/X models with a mean absolute percentage error (MAPE) of approximately 20%. The performance of the ARIMAX model was comparable to that of the ARIMA model with a MAPE reaching approximately 30%.
The RF model fitted the dynamic nature of an infectious diarrhea epidemic well and delivered an ideal prediction accuracy. It comprehensively combined the synchronous and lagged effects of meteorological factors; it also integrated the autocorrelation and seasonality of the morbidity. The RF model can be used to predict the epidemic level and has a high potential for practical implementation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•The prevalence of comorbid depressive symptoms in schizophrenia patients treated with atypical antipsychotics was 53.8%.•Patients with depressive symptoms showed higher serum levels of LDL and TC ...compared to patients without depressive symptoms.•Serum levels of LDL and TC were significantly positive associated with HAMD total scores in schizophrenia patients after age, sex and education levels were controlled.
This study aimed to explore the relationship between serum levels of cardiometabolic biomarkers and depressive symptoms in schizophrenia patients treated with atypical antipsychotics. A total of 210 patients with schizophrenia and 70 healthy controls were recruited in our present study. All patients were rated on the 17-item Hamilton Depression Rating Scale (HAMD-17) to measure depressive symptoms and the Positive and Negative Syndrome Scale (PANSS) for psychopathology. Serum cardiometabolic biomarkers (HDL, LDL, TC, TG, GLU) in all participants were measured. Our results showed that schizophrenia patients had higher levels of serum GLU, TG, TC, LDL and BMI, but lower levels of HDL than controls (all P < 0.05). Compared to patients without depressive symptoms, those with depressive symptoms showed higher PANSS total, general psychopathology, positive and negative symptom scores (all p < 0.05), as well as higher serum levels of LDL (p < 0.001) and TC (p = 0.011). In addition, our correlation analysis showed that serum LDL (P < 0.001) and TC (P = 0.045) levels were positively associated with HAMD total scores in schizophrenia patients after age, sex and education levels were controlled. Our results suggest the appearance of depression in schizophrenia patients may be associated with high levels of metabolic parameters, especially TC and LDL.
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