MiR-223-5p inhibitor suppresses microglia inflammation and promotes Nrg-1 in rats of spinal cord injury

OBJECTIVE

The aim of this study was to investigate the role of microRNA-233-5p (miR-233-5p) in spinal cord injury (SCI), and to explore the possible underlying mechanism.

MATERIALS AND METHODS

Microglia were first isolated from neonate rats and cultured in a suitable environment in vitro. Lipopolysaccharide (LPS) and interleukin-4 (IL-4) were used to activate microglia. The expressions of miR-223-5p, inducible nitric oxide synthase (iNOS) and arginase 1 (Arg-1) were measured by qRT-PCR, respectively. After transfection of miR-233-5p inhibitor, the expression levels of miR-223-5p, iNOS and Arg-1 in cells were detected as well. A moderate SCI model was successfully established in rats (10 g fallen on T10 spinal cord at the height of 5 cm). Subsequently, inflammation indexes at miR-223-5p peak moment were observed. Meanwhile, its neuro-protective effect at 28 days after SCI was estimated. Finally, Basso, Beattie, and Bresnahan (BBB) rating scale was applied to evaluate the hindlimb locomotor function of rats at 1, 3, 7, 14, 21, 28 days after SCI.

RESULTS

MiR-223-5p inhibitor significantly promoted M2 microglia expression and degenerated M1 microglia expression in vitro. SCI elevated the level of miR-223-5p in injured spinal cord tissues within one week, which reached a peak at 5 days after injury. Meanwhile, miR-223-5p inhibitor remarkably reduced the expressions of inflammatory factors, including interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) at 3 days after SCI, as well as increased neuregulin1 (NRG-1) expression. However, miR-223-5p inhibitor significantly declined the levels of apoptosis key enzyme-caspase-3 and glia reaction marker-glial fibrillary acidic protein (GFAP) at 7 and 28 days after SCI, respectively. As a result, BBB rating scale demonstrated that hindlimb locomotor function was significantly recovered in miR-223-5p injection group.

CONCLUSIONS

MiR-223-5p was up-regulated in M1 microglia, whereas down-regulated in M2 microglia. MiR-223-5p inhibitor could significantly increase M2 microglia expression, while decrease M1 microglia expression in vitro. In vivo, miR-223-5p inhibitor suppressed the inflammatory response and reinforced NRG-1 level to reduce glia reaction and neuron apoptosis. Thereby, its treatment promoted the hindlimb locomotor function of rats.

No pulsed radio emission during a bursting phase of a Galactic magnetar

Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

Periodontal Inflammation Primes the Systemic Innate Immune Response

The presence of periodontal diseases (PDs) often strongly correlates with other severe chronic inflammatory conditions, including cardiovascular disease, diabetes, and arthritis. However, the mechanisms through which these diseases interact are unclear. In PD, tissue and bone destruction in the mouth is driven by elevated recruitment of polymorphonuclear neutrophils (PMNs), which are primed and recruited from the circulation to sites of inflammation. We predicted that systemic effects on PMN mobilization or priming could account for the interaction between PD and other inflammatory conditions. We tested this using a mouse model of ligature-induced PD and found elevated PMN counts specifically in bone marrow, supporting a systemic effect of periodontal tissue inflammation on PMN production. In contrast, mice with induced peritonitis had elevated PMN counts in the blood, peritoneum, and colon. These elevated counts were further significantly increased when acute peritonitis was induced after ligature-induced PD in mice, revealing a synergistic effect of multiple inflammatory events on PMN levels. Flow cytometric analysis of CD marker expression revealed enhanced priming of PMNs from mice with both PD and peritonitis compared to mice with peritonitis alone. Thus, systemic factors associated with PD produce hyperinflammatory PMN responses during a secondary infection. To analyze this systemic effect in humans, we induced gingival inflammation in volunteers and also found significantly increased activation of blood PMNs in response to ex vivo stimulation, which reverted to normal following resolution of gingivitis. Together, these results demonstrate that periodontal tissue inflammation has systemic effects that predispose toward an exacerbated innate immune response. This indicates that peripheral PMNs can respond synergistically to simultaneous and remote inflammatory triggers and therefore contribute to the interaction between PD and other inflammatory conditions. This suggests larger implications of PD beyond oral health and reveals potential new approaches for treating systemic inflammatory diseases that interact with PD.

Advances in SARS-CoV-2: a systematic review

OBJECTIVE

In December 2019, Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection broke out in Wuhan, China. However, we still lack a comprehensive understanding of this emerging virus. In this manuscript, we collected relevant articles and reviewed the characteristics about SARS-CoV-2.

MATERIALS AND METHODS

We performed an online search on PubMed and Web of Science with the keywords COVID-19, 2019-nCoV and SARS-CoV-2, and summarized the epidemiology, virology, clinical features and treatments of SARS-CoV-2 infection.

RESULTS

We retrieved 157 published papers about SARS-CoV-2 from January, 2020 to April, 2020. We found that SARS-CoV-2 was a kind of virus with low mortality rate and high infectivity. This virus can enter human cells through angiotensin-converting enzyme 2 (ACE2) in alveoli and activate immune response in human body. SARS-CoV-2 infection can be classified as asymptomatic, mild, common, severe, and critical. We summarized antiviral drugs against SARS-CoV-2, such as remdesivir, hydroxychloroquine and favipiravir. Because the vaccine of SARS-CoV-2 is developing, more clinical studies are needed to verify the safety and efficacy of these treatments.

CONCLUSIONS

SARS-CoV-2 is a novel coronavirus that has caused a global pandemic. We should pay more attention to prevent SARS-CoV-2 and try to control it sooner.

[Current status of the clinical practice and analysis on the ratioanl prescription of antiarrhythmic drugs in Chinese patients with atrial fibrillation: Results from the Chinese Atrial Fibrillation Registry (CAFR) trial]

Objective: To explore the practice patterns and the related factors of oral antiarrhythmic drug (AAD) treatment in Chinese patients with atrial fibrillation (AF), and to evaluate the compliance of AAD application to atrial fibrillation management guidelines. Methods: From August 2011 to August 2016, medical records from 18 014 patients with AF were analyzed based on data from the Chinese Atrial Fibrillation Registry trial. Patients were divided into AAD group (7 788 cases, 43.23%) and non-AAD group (10 226 cases, 56.77%) according to whether AAD was used at baseline or at the time of first use during follow-up. Amiodarone (4 129 cases, 53.02%) and propafenone (3 211 cases, 41.23%) were the mostly prescribed AAD and subgroup analysis was performed accordingly. Medical records were analyzed by random forest regression to evaluate the use of AAD and related factors in patients with AF, and the rationality of AAD was analyzed according to the guidelines for the management of atrial fibrillation. Result: A total of 18 014 patients were included in this study, of which 60.48% (10 895/18 014) were male patients, 22.65% (4 081/18 014) were elderly patients(≥75 years old), there were 7 788 patients (43.23%) in AAD group, and 10 226 patients(56.77%) in non-AAD group. Compared with the non-AAD group, the elderly patients (≥75 years old, 13.74%(1 070/7 788) vs. 29.44%(3 011/10 226)), persistent AF (28.95% (2 250/7 788) 45.80% (4 683/10 226)), heart failure(8.29% (646/7 788) vs. 21.95% (2 245/10 226)), stroke and (or) TIA(12.15% (946/7 788) vs. 19.95% (2 040/10 226)), renal dysfunction(16.36%(1 274/7 788) vs. 29.37% (3 003/10 226)), and high thromboembolism risk(60.17% (4 748/7 788) vs. 76.40% (7 813/10 226)) were less prevalent in the AAD subgroup (P<0.001). Multivariate analysis showed that patients in tertiary hospitals (OR=3.72, 95%CI 3.17-4.37) were more likely to use AAD, elderly patients (≥75 years old, OR=0.47, 95%CI 0.39-0.55), persistent atrial fibrillation (OR=0.66, 95%CI 0.60-0.72), and patients with heart failure (OR=0.54, 95%CI 0.47-0.63), stroke and (or) TIA (OR=0.77, 95%CI 0.68-0.87), renal dysfunction (OR=0.75, 95%CI 0.59-0.95) and high thromboembolism risk(OR=0.7, 95%CI 0.58-0.84) were more likely not to use AAD(P<0.05). In the AAD group, amiodarone and propafenone were the most commonly used AAD, accounting for 53.02% (4 129/7 788) and 41.23% (3 211/7 788), respectively. Multivariate analysis showed that patients with persistent atrial fibrillation (OR=4.57, 95%CI 3.94-5.29) and coronary heart disease (OR=4.14, 95%CI 3.03-5.64), heart failure (OR=2.07, 95%CI 1.48-2.89), non-ischemic cardiomyopathy (OR=4.84, 95%CI 2.41-9.73) were more likely to use amiodarone, and those with normal left ventricular ejection fraction (OR=0.31, 95%CI 0.15-0.65) and low thromboembolism risk (OR=0.78, 95%CI 0.63-0.97) were more likely to use propafenone (P<0.001). The overall incidence of AAD treatment, which was not indicated by the guidelines was 6.5% (480/7 340); 5.1% (212/4 129) in the amiodarone group and 8.3% (268/3 211) in the propafenone group, respectively. Compared with the rational AAD use group, the proportion of irrational drug use was higher in the elderly (≥75 years old) (20.4% (98/480) vs. 12.9% (887/6 860)), patients of high thromboembolism risk (77.1% (379/480) vs. 59.0% (4 047/6 860)), and in non-tertiary hospitals (7.1% (34/480) vs. 3.3% (299/6 860)), but lower in men(50.8% (244/480) vs. 64.5% (4 427/6 860)), P<0.001. Conclusions: The patients with paroxysmal atrial fibrillation, who were treated with AAD, were mostly patients with fewer complications, and the patients who were treated with amiodarone were mostly patients with persistent atrial fibrillation, patients were more likely to complicate with organic heart disease. The incidence of AAD that do not comply with the guidelines was low, and it was more common in non-tertiary hospitals and the elder patients with high thromboembolism risk.

Low dose novel PARP-PI3K inhibition via nanoformulation improves colorectal cancer immunoradiotherapy

Multimodal therapy is often used in oncology to overcome dosing limitations and chemoresistance. Recently, combination immunoradiotherapy has shown great promise in a select subset of patients with colorectal cancer (CRC). Furthermore, molecularly targeted agents delivered in tandem with immunotherapy regimens have been suggested to improve treatment outcomes and expand the population of responding patients. In this study, radiation-sensitizing small molecules niraparib (PARP inhibitor) and HS-173 (PI3K inhibitor) are identified as a novel combination that synergistically enhance toxicity and induce immunogenic cell death both in vitro and in vivo in a CRC model. These inhibitors were co-encapsulated in a polymer micelle to overcome solubility limitations while minimizing off-target toxicity. Mice bearing syngeneic colorectal tumors (CT26) were administered these therapeutic micelles in combination with X-ray irradiation and anti-CTLA-4 immunotherapy. This combination led to enhanced efficacy demonstrated by improved tumor control and increased tumor infiltrating lymphocytes. This report represents the first investigation of DNA damage repair inhibition combined with radiation to potentiate anti-CTLA-4 immunotherapy in a CRC model.

Innovative hydrolysis of corn stover biowaste by modified magnetite laccase immobilized nanoparticles

Intensive studies have been performed on the improvement of bioethanol production by transformation of lignocellulose biomass. In this study, the digestibility of corn stover was dramatically improved by using laccase immobilized on Cu²⁺ modified recyclable magnetite nanoparticles, Fe₃O₄-NH₂. After digestion, the laccase was efficiently separated from slurry. The degradation rate of lignin reached 40.76%, and the subsequent cellulose conversion rate 38.37% for 72 h at 35 °C with cellulase at 50 U g^-1 of corn stover. Compared to those of free and inactivated mode, the immobilized laccase pre-treatment increased subsequent cellulose conversion rates by 23.98% and 23.34%, respectively. Moreover, the reusability of immobilized laccase activity remained 50% after 6 cycles. The storage and thermal stability of the fixed laccase enhanced by 70% and 24.1% compared to those of free laccase at 65 °C, pH 4.5, respectively. At pH 10.5, it exhibited 16.3% more activities than its free mode at 35 °C. Our study provides a new avenue for improving the production of bioethanol with immobilized laccase for delignification using corn stover as the starting material.

Identification, characterization and functional differentiation of the NAC gene family and its roles in response to cold stress in ginseng, Panax ginseng C.A. Meyer

The NAC gene family is one of the important plant-specific transcription factor families involved in variety of physiological processes. It has been found in several plant species; however, little is known about the gene family in ginseng, Panax ginseng C.A. Meyer. Here we report identification and systematic analysis of this gene family in ginseng. A total of 89 NAC genes, designated PgNAC01 to PgNAC89, are identified. These genes are alternatively spliced into 251 transcripts at fruiting stage of a four-year-old ginseng plant. The genes of this gene family have five conserved motifs and are clustered into 11 subfamilies, all of which are shared with the genes of the NAC gene families identified in the dicot and monocot model plant species, Arabidopsis and rice. This result indicates that the PgNAC gene family is an ancient and evolutionarily inactive gene family. Gene ontology (GO) analysis shows that the functions of the PgNAC gene family have been substantially differentiated; nevertheless, over 86% the PgNAC transcripts remain functionally correlated. Finally, five of the PgNAC genes, PgNAC05-2, PgNAC41-2, PgNAC48, PgNAC56-1, and PgNAC59, are identified to be involved in plant response to cold stress, suggesting that this gene family plays roles in response to cold stress in ginseng. These results, therefore, provide new insights into functional differentiation and evolution of a gene family in plants and gene resources necessary to comprehensively determine the functions of the PgNAC gene family in response to cold and other abiotic stresses in ginseng.

[Clinical analysis of 150 cases of 2019 novel coronavirus infection in Nanyang City, Henan Province]

Objective: To analyze the epidemiological characteristics and clinical features of the patients with 2019-nCoV infection in Nanyang City, so as to provide evidence for clinical diagnosis and treatment. Methods: The epidemiology, clinical symptoms, atory and radiologic data of 150 patients with 2019-nCoV infection admitted to the designated hospitals in Nanyang City from January 24,2020 to February 16, 2020 were retrospectively analyzed. Results: The 150 patients with 2019 nCov infection consisted of 67 men and 83 women, and the median age was (45±16) years; 69 of them were the first generation case,60 of them were the second generation case, 6 of them were the third generation case,the median incubation period of the first generation case was (5.4±2.2) days, and the second generation case was (6.7±3.1) days, and the first-generation cases are the majority in severe patients (69%) . The most common basic disease was hypertension (13 cases, 9%), diabetes (9 cases, 6%), and the most common symptom is fever(142 cases, 95%, 63% showed moderate fever) , cough and sputum(108 cases,72%), fatigue(23 cases,15%), anorexia(20 cases, 13%), headache, diarrhea, muscle soreness, sore throat as the first symptoms. The average time from onset of symptoms to consultation was (4.2±2.2) days for all patients. The changes in peripheral blood cells were mainly lymphonpenia (83 cases, 55%) and eosinophilia (95 cases, 63%), The lymphocyte count of the severe and critically ill patients was more significantly reduced, and some patients had increased myocardial enzymes, mainly LDH (47 cases, 31%), and a few patients had liver function damage, mainly manifested in ALT and AST. High, very few patients have renal impairment. Among the inflammation-related indicators, the main manifestations are increased CRP (66 cases, 43%) and ESR (86 cases, 57%), elevated D-Dimer in 29% of patients. 144 cases have different degrees of infective lesions in chest CT examination, with 30 cases (21%) on one side and 144 cases (79%) on both sides. Morphologically, most of the lesions were patchy ground glass lesions, which could be accompanied by air bronchus signs and some consolidation and paving stone signs. Of the cases showing "white lung", 87% were sever ill or critically ill. After active treatment, 45% of patients were discharged according to discharge standards. 33% of sever and critically ill patients were discharged, 49% of them were degraded hospitalization.The average length of hospitalization was (12±4) days. Conclusion: A history of epidemiological exposure, fever, chest CT with signs of pneumonia, normal or decreased WBC, and lymphocytopenia, eosinophilia are the clinical basis for the diagnosis of this disease, and most of the sever patients were the first generation cases. The degree of lymphocytopenia is related to the severity of the disease.

Rapid isolation of non-aflatoxigenic Aspergillus flavus strains

In the present study, a method for screening non-aflatoxigenic Aspergillus flavus in soil samples collected from major peanut-growing regions of China was developed. The single colonies were picked and cultured on Aspergillus flavus and parasiticus agar (AFPA). If the reverse side of the colony on AFPA was orange-coloured, it was considered A. flavus or Aspergillus parasiticus. After the genomic DNA of each strain was extracted, 28S rRNA and calmodulin were amplified and sequenced to determine the species. The key gene, aflR, was amplified and digested via polymerase chain reaction-restriction fragment length polymorphism. The aflatoxigenic A. flavus and the non-aflatoxigenic A. flavus and A. parasiticus were distinguished by enzyme digestion of aflR. 156 strains of A. flavus were screened, which consisted of 135 aflatoxigenic and 21 non-aflatoxigenic strains. The aflatoxin producing ability of each strain was confirmed using solid-state fermentation experiments. Using the method developed in the present study, we confirmed that the non-aflatoxigenic A. flavus strains isolated lost their capacity to produce aflatoxins. Considering there could be some alterations in other functional genes, some non-aflatoxigenic strains could be identified inaccurately as aflatoxigenic strains, although that did not occur in the present study. The growth of non-aflatoxigenic A. flavus was observed, and the most rapidly growing non-aflatoxigenic strain was selected for plate confrontation assays and toxic mixed culture experiments. The inhibition rate of non-aflatoxigenic A. flavus against aflatoxigenic A. flavus was 55.4 and 72.6% in potato dextrose agar (PDA) plate and natural soybean medium, respectively. The screened non-aflatoxigenic A. flavus strains provide a microbial resource for biological control of aflatoxin contamination.

Chinese expert group consensus on diagnosis and clinical management of osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible (MORN) is one of the most devastating complications caused by radiation therapy in the head and neck region. It is characterized by infection and chronic necrosis of the mandible as the main manifestation. Clinically, MORN-related symptoms include swelling, pain, dysphagia, trismus, masticatory or speech disorders, refractory orocutaneous fistula, bone exposure, and even pathological fracture. MORN has become a challenging clinical problem for oral and maxillofacial surgeons to deal with, but thus far, this problem has not been solved due to the lack of widely accepted treatment algorithms or guidelines. Because of the nonexistence of standardized treatment criteria, most clinical treatment against MORN nowadays is largely based on controversial empirical understandings, while recommendations on post-therapeutic evaluations are scarce. Therefore, to further unify and standardize the diagnosis and treatment of MORN, to decrease the huge waste of medical resources, and ultimately, to improve the wellbeing of the patients, the Chinese Society of Oral and Maxillofacial Surgery (CSOMS) convened an expert panel specialized in MORN from 16 domestic medical colleges and affiliated hospitals to discuss the spectrum of diagnosis and and formulate treatment. In addition, consensus recommendations were also revised with a comprehensive literature review of the previous treatment experiences and research pearls. This 'expert consensus statement on diagnosis and clinical management of MORN' is for clinical reference.

[Research progress on urogenital function preservation in extralevator abdominoperineal resection]

Extralevator abdominoperineal excision (ELAPE) has been suggested to potentially improve oncological outcomes in advanced low rectal cancer patients. However, the urogenital function impairment as one of the main complications deteriorates the quality of life in these patients. The key point to prevent urogenital function impairment is to avoid autonomic nerve injury, including the superior and inferior hypogastric nerve plexus and neurovascular bundle. Three areas should be especially focused during surgery, including the posterolateral aspect of the prostate during the separation of the rectum from prostate, the lateral wall of ischioanal fossa and the area in front of anal canal. Previous presumption supposed that extended resection, though promoting oncologic outcomes, might lead to enlarged injury to surrounding vessels and nerves that deteriorated patients' urogenital function. But recent studies show that postoperative urogenital function outcomes of rectal cancer patients who underwent ELAPE are not inferior to conventional APE after the induction of minimal invasive approaches including laparoscopic and robotic surgery. Their quality of life can be comparable with patients who underwent conventional APE, and are even better in some particular area. Moreover, as further improvement of ELAPE procedure has been made, the concept of individualized ELAPE addressed the importance of personalized surgical procedure based on tumor stage and location, dedicating to avoid injury to vessels and nerves through preserving more surrounding tissues. Urogenital function outcomes, as part of postoperative outcomes, get more and more attention in recent years. We review current studies on urogenital function after ELAPE from anatomy to clinical research, in order to raise surgeons' attention of nerve preservation technique and to improve their understanding of ELAPE procedure.

[A review of immune-related adverse events associated with immunotherapy]

Immune checkpoint inhibitors have been approved for clinical application in China. However, the increased immune-related adverse event (irAE) needs more attention. This review summarized the incidence, characteristic clinical manifestation and treatment of irAEs associated with programmed cell death protein-1(PD-1) and programmed cell death ligand-1(PD-L1) inhibitors. To have a deep insight into irAE, the potential mechanisms, the different incidences of cancer types, influencing factors and the direction of future research were also discussed here to provide guidance for clinical oncologist to identify and monitor irAE.

Selection and validation of reference genes desirable for gene expression analysis by qRT-PCR in MeJA-treated ginseng hairy roots

Ginseng is a valuable herb of traditional Chinese medicine and ginsenosides, the main bioactive components of ginseng, have been proven to have multiple functions in human therapies and health. Methyl jasmonate (MeJA) is an elicitor that has been demonstrated to have a vital influence on ginsenoside biosynthesis. Quantitative real-time polymerase chain reaction (qRT-PCR) has been widely used in quantification of gene expressions. Here, we report the selection and validation of reference genes desirable for normalization of gene expressions quantified by qRT-PCR in ginseng hairy roots treated with MeJA. Twelve reference genes were selected as candidate genes, and their expressions were quantified by qRT-PCR, and analyzed by geNorm, NormFinder and BestKeeper. CYP and EF-1α were shown to be the most stable reference genes in geNorm, CYP was the most stable reference gene in NormFinder, and 18S was the most stable reference gene in BestKeeper. On this basis, we further quantified the relative expression levels of four genes encoding key enzymes that are involved in ginsenoside biosynthesis using CYP and 18S as the reference genes, respectively. Moreover, correlation analysis was performed between the quantified expressions of four genes and the ginsenoside content in MeJA-treated ginseng hairy roots. The results of relative expressions of the four genes quantified using CYP as the reference gene and their significant correlations with the ginsenoside content were better than those using 18S as the reference gene. The CYP gene, hence, was concluded as the most desirable reference gene for quantification of the expressions of genes in MeJA-treated ginseng hairy roots. This finding, therefore, provides information useful for gene research in ginseng, particularly in MeJA-treated ginseng hairy roots, which includes identification and characterization of genes involved in ginsenoside biosynthesis.

Resistive Switching Mechanism of HfO₂ Based Resistance Random Access Memory Devices with Different Electrode Materials

This study investigated the impact of electrode materials on HfO₂-based RRAM devices. The research includes three types of electrode materials: (1) the electrodes with strong ability of oxygen reservoirs; (2) the electrode with poor ability of oxygen reservoirs; (3) the active electrode with injection ability. Through implementing different combinations of electrodes, three types of switching modes were obtained and the relative conduction mechanism was analyzed, as well as conduction model. Those studies may offer ways of using electrodes to control the resistive switching processes and fabricating the RRAM devices with good performance.

Targeted inhibition of β-catenin by miR-320 and decreased MMP-13 expression in suppressing chondrocyte collagen degradation

OBJECTIVE

Wnt/β-catenin pathway plays a critical role in modulating embryonic development, cell growth, and differentiation. The over-expression of β-catenin activates this pathway and up-regulates expression of matrix metalloproteinase-13 (MMP-13), and promotes matrix degradation and occurrence of osteoarthritis (OA). This study aims to explore the effect of miR-320 expression in OA chondrocyte and underlying mechanisms.

PATIENTS AND METHODS

Chondrocyte tissues from OA patients and normal individuals were collected for the detection of expression levels of miR-320, β-catenin, MMP-13, and alpha-1 chain of type II collagen (COL2A1). Dual luciferase reporter assay was performed to test targeted regulation between miR-320 and β-catenin. IL-1β was used to simulate in vitro cultured chondrocytes, which were transfected with miR-320 mimic and/or si-β-catenin, followed by quantification of miR-320, β-catenin, MMP-13, and COL2A1.

RESULTS

In chondrocytes of OA patients, expression of microRNA (miR)-320 is decreased. Bioinformatics analysis revealed complementary binding sites between miR-320 and β-catenin. Compared to control group, increasing levels of β-catenin and MMP-13 expression with reduction of miR-320 and COL2A1 expressions were observed in OA chondrocytes. Transfection of miR-320 mimic and/or si-β-catenin depressed expression of β-catenin and MMP-13 inside chondrocytes, accompanied with elevation of COL2A1 expression.

CONCLUSIONS

MiR-320 expression in OA chondrocyte is decreased, accompanied with up regulation of β-catenin and MMP-13. MiR-320 can inhibit β-catenin and MMP-13 expressions, elevates COL2A1 expression, which provides novel insights for the treatment of osteoarthritis.

Demonstration of Machine Learning-Based Model-Independent Stabilization of Source Properties in Synchrotron Light Sources

Synchrotron light sources, arguably among the most powerful tools of modern scientific discovery, are presently undergoing a major transformation to provide orders of magnitude higher brightness and transverse coherence enabling the most demanding experiments. In these experiments, overall source stability will soon be limited by achievable levels of electron beam size stability, presently on the order of several microns, which is still 1-2 orders of magnitude larger than already demonstrated stability of source position and current. Until now source size stabilization has been achieved through corrections based on a combination of static predetermined physics models and lengthy calibration measurements, periodically repeated to counteract drift in the accelerator and instrumentation. We now demonstrate for the first time how the application of machine learning allows for a physics- and model-independent stabilization of source size relying only on previously existing instrumentation. Such feed-forward correction based on a neural network that can be continuously online retrained achieves source size stability as low as 0.2  μm (0.4%) rms, which results in overall source stability approaching the subpercent noise floor of the most sensitive experiments.