Antibacterial photodynamic properties of silver nanoparticles-loaded curcumin composite material in chitosan-based films.

In order to cope with the increasingly severe food contamination and safety problems, a powerful sterilization of food packaging material is urgently needed. Chitosan (CS) has potential applications in food packaging due to its good film-forming properties, but its antibacterial activity is not sufficient to meet the needs in practical applications. Silver nanoparticles (AgNPs) have the problem of weak immediate antibacterial activity as a broad-spectrum antibacterial agent. Therefore, in this study, AgNPs@GA@Cur-POTS (AGCP) composite antibacterial system was prepared by combining AgNPs with antibacterial photodynamic therapy using gallic acid (GA) as a reducing agent, curcumin (Cur) as a photosensitizer and perfluorosilane (POTS) for surface modification. The results showed that AGCP could produce a large number of reactive oxygen species under blue light irradiation, killing >90 % of E. coli and S. aureus within 2 h. Subsequently, the composite film of CS loaded with AGCP (CS/AGCP) was prepared by the flow-delay method. The CS/AGCP composite film exhibited excellent barrier properties and antioxidant activity, while its antibacterial rates against E. coli and S. aureus reached 98.44 ± 1.27 % and 99.11 ± 0.24 %, respectively, while the OD630 values of the two groups of bacteria treated with it showed no significant increase in incubation for up to 132 h, exhibiting remarkable and sustained antibacterial effects. Taken together, this work will provide a new strategy for antibacterial food packaging.

Morphogenesis and metabolomics reveal the compatible relationship among Suillus bovinus, Phialocephala fortinii, and their co-host, Pinus massoniana.

Ectomycorrhizal (ECM) fungi and dark septate endophytes (DSEs) can both form a symbiotic relationship with the same host plant. However, the interactions that occur among these two types of fungi and their co-hosts are largely unknown. Here, we investigated interactions that occur among the ECM fungus Suillus bovinus, the DSE Phialocephala fortinii, and their co-host Pinus massoniana. We used both scanning electron microscopy and optical microscopy to characterize the morphogenesis of the two symbionts and employed the ultra-high-performance liquid chromatography-tandem mass spectrometry technique to assess the effects of fungal inoculation on the root metabolome. Under pure culture conditions, no synergistic or antagonistic effects were observed between Phi. fortinii and S. bovinus. Generally, S. bovinus and Phi. fortinii can simultaneously colonize P. massoniana roots without affecting each other's symbiotic processes. S. bovinus can colonize the root locus where Phi. fortinii has already invaded but not vice versa, which may be due to the physical barrier effect of the mantle. Both fungi can significantly promote the growth of P. massoniana, and they have a synergistic effect on host N and K uptake. Metabolite accumulation patterns in roots inoculated with Phi. fortinii and/or S. bovinus were greatly altered, especially with respect to organic acids, flavonoids, lipids, and phenolic acids. S. bovinus inoculation significantly enhanced root flavonoid biosynthesis, whereas Phi. fortinii and dual-inoculation treatments mainly induced phenylpropanoid biosynthesis. These findings reveal compatible relationships among P. massoniana, S. bovinus, and Phi. fortinii, and suggest a theoretical basis for ECM fungi and DSE co-application when cultivating seedlings. IMPORTANCE The prevalence of both ectomycorrhizal fungi and dark septate endophytes in the roots of a wide spectrum of tree species is well recognized. In this study, we investigated the interactions that occur among the ECM fungus S. bovinus, the DSE Phi. fortinii, and their co-host, P. massoniana. The two fungi can simultaneously colonize P. massoniana roots without affecting each other's symbiotic processes. S. bovinus appears to be superior to Phi. fortinii in microniche competition, which may be due to the physical barrier effect of the mantle. The two fungi have different effects on root metabolite accumulation patterns. S. bovinus inoculation significantly enhanced root flavonoid biosynthesis, whereas Phi. fortinii and dual-inoculation treatments mainly induced phenylpropanoid biosynthesis. This is the first study revealing the morphological and metabolic mechanisms that contribute to the compatible relationship among ECM fungi, DSEs, and their co-host.

High PD-L1 expression associates with low T-cadherin expression and poor prognosis in human papillomavirus-negative head and neck squamous cell carcinoma.

BACKGROUND: This study aimed at exploring the correlation between T-cadherin and programmed death-ligand 1 (PD-L1), as well as their prognostic value in patients with human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). METHODS: Immunohistochemical staining was used to identify the protein expression of T-cadherin and PD-L1. Spearman linear correlation analysis was used to determine their association. Kaplan-Meier analysis was utilized to plot overall survival (OS) and disease-free survival (DFS) curves. Cox proportional hazards regression was used to conduct univariate and multivariate analysis. RESULTS: The results showed a negative association between protein expression of T-cadherin and PD-L1 (r = -0.760, p < 0.001), positive expression of T-cadherin was associated with a better OS (p < 0.001) and DFS (p < 0.001), while positive PD-L1 expression was associated with a worse OS (p = 0.002) and DFS (p < 0.001). The expression of T-cadherin and PD-L1 were independent prognostic predictors for OS and DFS. CONCLUSIONS: In conclusion, expression of T-cadherin and PD-L1 were largely inversely correlated and independent prognostic factors for patients with HPV-negative HNSCC.

[Research progress in targeting autophagy of traditional Chinese medicine and natural compounds to regulate atherosclerosis].

Atherosclerosis(AS) is the common pathological basis of many ischemic cardiovascular diseases, and its formation process involves various aspects such as vascular endothelial injury and platelet activation. Vascular endothelial injury is the initiating factor of AS plaque. Monocytes are recruited to differentiate into macrophages at the damaged endothelial cells, which absorb oxidized low-density lipoprotein(ox-LDL) and slowly transform into foam cells. Smooth muscle cells(SMCs) proliferate and migrate continuously. As the only cell producing interstitial collagen fibers in the fibrous cap, SMCs largely determine whether the plaque ruptured or not. The amplifying inflammatory response during the formation of AS recruits platelets to adhere to the damaged area of vascular endothelium and stimulates excessive platelet aggregation. Autophagy activity is associated with vascular lesions and abnormal platelet activation, and excessive autophagy is considered to be a negative factor for plaque stability. Therefore, precise regulation of different types of vascular autophagy and platelet autophagy to treat AS may provide a new therapeutic perspective for the prevention and treatment of atherosclerotic ischemic cardiovascular disease. Currently, treatment strategies for AS still focus on lowering lipid levels with high-intensity statins, which often cause significant side effects. Therefore, the development of safer and more effective drugs and treatment modes is the focus of current research. Traditional Chinese medicine and natural compounds have the potential to treat AS by targeted autophagy, and have been playing an increasingly important role in the prevention and treatment of cardiovascular diseases in China. This paper summarizes the experimental studies on different vascular cell types and platelet autophagy in AS, and sums up the published research results on targeted autophagy of traditional Chinese medicine and natural plant compounds to regulate AS, providing new ideas for further research.

Preparation and characterization of PVA/arginine chitosan/ZnO NPs composite films.

In this study, arginineated chitosan (ACS) was used as a soft brain membrane and chelating agent to synthesize ACS-ZnO NPs, and then ACS and ACS-ZnO NPs were added to a polyvinyl alcohol (PVA) matrix as an antimicrobial agent to form films by casting. The formation and structural morphology of ACS and ACS-ZnO NPs were investigated by applying FTIR, 1H NMR, XRD, EDS, SEM, and TEM techniques, and ACS has shown better water solubility. The cytotoxicity experiments of ACS and ACS-ZnO NPs on A549 cells showed that both had good cytocompatibility. The incorporation of ACS and ACS-ZnO NPs improves the composite film's mechanical properties, water barrier, and oxygen barrier and exhibits excellent antibacterial activities against S. aureus and E. coli. More importantly, in addition to extending the shelf life of cherry tomatoes, the composite film is also biodegradable to some degree. Therefore, polyvinyl alcohol films based on ACS and ACS-ZnO NPs added as antimicrobial agents have great potential for food packaging applications.

Gallic acid functionalized chitosan immobilized nanosilver for modified chitosan/Poly (vinyl alcohol) composite film.

Food spoilage caused by bacterial growth is a serious threat to human health. Silver nanoparticles (AgNPs) have antibacterial activity against various pathogenic microorganisms, but their rapid release often leads to cumulative toxicity. In this paper, silver nanoparticles (AgNPs@CG) were reduced and immobilized in situ using gallic acid-functionalized chitosan (CG) as a reducing and stabilizing agent to achieve a long-lasting and stable controlled release of Ag+. The AgNPs@CG was incorporated into the CG/PVA composite film. The results showed that the release of Ag+ was only 0.686 ± 0.022 mg·L-1 after seven days, which had a long-lasting antibacterial effect on E. coli and S. aureus. In addition, CG/PVA/AgNPs-2 composite film can significantly improve the freshness preservation effect in fresh-cut apple preservation applications. In conclusion, CG/PVA/AgNPs composite film has potential applications as effective and safe packaging material to extend the shelf life of food products.

Research Progress of Ferroptosis Regulatory Network and Bone Remodeling in Osteoporosis.

Ferroptosis was induced the programmed cell death with iron overload Fenton reaction. Currently, ferroptosis has not been studied thoroughly. Existing studies have confirmed that ferroptosis involves the metabolisms of the Fe, lipids, amino acid, each mechanism is mutually independent but interrelated, and they are formed a complex regulatory network. Other evidence supports that ferroptosis is participated osteoporotic bone remodeling, predominantly affecting the interaction between bone formation and bone resorption, explicitly bone resorption exceeded bone formation. Based on previous studies, this review will summarize the regulatory network mechanism of ferroptosis on bone remodeling and reveal the role of ferroptosis in osteoporosis (OP).

Zhongfeng Capsules protects against cerebral ischemia-reperfusion injury via mediating the phosphoinositide 3-kinase/Akt and toll-like receptor 4/nuclear factor kappa B signaling pathways by regulating neuronal apoptosis and inflammation.

Inflammatory reaction and neuronal apoptosis are the major pathophysiological mechanisms involved in cerebral ischemia-reperfusion injury (CI/RI). It has been reported that Zhongfeng Capsules (ZFCs), which contain Panax notoginseng, Hirudo, Red ginseng, Eupolyphaga sinensis, Pangolin scales, Rhubarb, and Radix Salvia miltiorrhizae, have a definite therapeutic effect on CI/RI. However, the specific molecular mechanisms of ZFCs are unclear. In this study, the effects of ZFCs on middle cerebral artery occlusion were investigated in rats. Our results showed that neurological impairment and neuronal apoptosis were alleviated in ZFC-treated rats. Additionally, infarct volume and cerebral edema decreased and there was an improvement in histopathological features. Furthermore, the expression levels of IL-1ß, IL-6, and TNF-α were downregulated in ZFC-treated rats. TLR 4, NF-κB, Bax, and Caspase-3 expression also tended to decrease, whereas the expression of Bcl-2, p-PI3K, p-Akt, and I-κBα increased. The results indicate that the ZFCs effectively protected the rats against CI/RI possibly via the TLR4/NF-κB signaling pathway. Additionally, the formulation regulated the transcriptional activity of NF-κB, secretion of downstream inflammatory factors, and the expression of Bcl-2-Bax proteins in the PI3K/Akt pathway. Our findings suggest that ZFCs suppress neuronal apoptosis and inflammatory reaction via the PI3K/Akt and TLR4/NF-κB signaling pathways, respectively. Moreover, activation of the PI3K/Akt pathway may result in the inhibition of proinflammatory cytokine secretion, which may be another mechanism by which ZFCs alleviate CI/RI.

[Effects of Zhongfeng capsule on autophagy related proteins expressions of brain tissue in rats with cerebral ischemia/reperfusion injury].

Objective: To investigate the effects of Zhongfeng capsule on the autophagy-related proteins expression in rats with cerebral ischemia/reperfusion injury (CI/ RI), and to explore its neural protection mechanisms of the decoction. Methods: Rat middle cerebral artery ischemia/reperfusion injury model (ischemia for 2 h, reperfusion for 24 h) was prepared by the improved line plug method. Sixty male SD rats were randomly divided into sham operation group, model group, butylphthalide group(0.054 g/kg), Zhongfeng capsule high-dose groups (1.08 g/kg), Zhongfeng capsule middle-dose groups (0.54 g/kg), Zhongfeng capsule low-dose groups (0.27 g/kg), with 10 rats in each group. Rats were treated with Zhongfeng capsule by gavage once a day for 10 days. The rats were sacrificed and the brain tissue was obtained after the experiment in each group. Score neurological deficit was evaluated after 24 h of the last intervention in rat of each group. The pathological changes of brain tissue were observed by HE staining. The serum levels of estradiol (E2) and follicle stimulating hormone (FSH) were determined by ELISA. The expressions of key genes and proteins of PI3K/Akt/Beclin1 signaling pathway in brain tissue were detected by qRT-PCR and Western blot respectively. Results: Compared with the sham operation group, the body weight and protein expressions of p-PI3k and p-Akt in brain tissue of rats were decreased significantly in the model group, while the brain index, neurological deficit score, gene and protein expressions of Beclin1 and LC3 were increased markedly in the model group(P＜0.05 or P＜0.01). In the model group, nerve cells of brain tissue were loosely packed, interstitial edema, triangular in shape, nuclear pyknosis and dark-blue staining were observed. Compared with the model group, the body weight of rats was increased obviously, the neurological deficit score was decreased significantly and the pathological injury of brain tissue was alleviated evidently in high-dose of Zhongfeng capsule group (P＜0.05). The brain index, the gene and protein expressions of Beclin1 and LC3 were decreased apparently in Zhongfeng capsule treatment groups(P＜0.05 or P＜0.01), while the expressions of p-PI3k and p-Akt in brain tissue were increased evidently in Zhongfeng capsule treatment groups(P＜0.05 or P＜0.01). Conclusion: Zhongfeng capsule can inhibit autophagy and improve brain neurons lesion of CIRI rats, the mechanism may be related to regulate the expression of Beclin1 and LC3 in PI3K/Akt/Beclin1 signaling pathway.

Ten-Hour Stable Noninvasive Brain-Computer Interface Realized by Semidry Hydrogel-Based Electrodes.

Noninvasive brain-computer interface (BCI) has been extensively studied from many aspects in the past decade. In order to broaden the practical applications of BCI technique, it is essential to develop electrodes for electroencephalogram (EEG) collection with advanced characteristics such as high conductivity, long-term effectiveness, and biocompatibility. In this study, we developed a silver-nanowire/PVA hydrogel/melamine sponge (AgPHMS) semidry EEG electrode for long-lasting monitoring of EEG signal. Benefiting from the water storage capacity of PVA hydrogel, the electrolyte solution can be continuously released to the scalp-electrode interface during used. The electrolyte solution can infiltrate the stratum corneum and reduce the scalp-electrode impedance to 10 kΩ-15 kΩ. The flexible structure enables the electrode with mechanical stability, increases the wearing comfort, and reduces the scalp-electrode gap to reduce contact impedance. As a result, a long-term BCI application based on measurements of motion-onset visual evoked potentials (mVEPs) shows that the 3-hour BCI accuracy of the new electrode (77% to 100%) is approximately the same as that of conventional electrodes supported by a conductive gel during the first hour. Furthermore, the BCI system based on the new electrode can retain low contact impedance for 10 hours on scalp, which greatly improved the ability of BCI technique.

High-throughput production of kilogram-scale nanofibers by Kármán vortex solution blow spinning.

The interaction between gas flow and liquid flow, governed by fluid dynamic principles, is of substantial importance in both fundamental science and practical applications. For instance, a precisely designed gas shearing on liquid solution may lead to efficacious production of advanced nanomaterials. Here, we devised a needleless Kármán vortex solution blow spinning system that uses a roll-to-roll nylon thread to deliver spinning solution, coupled with vertically blowing airflow to draw high-quality nanofibers with large throughput. A wide variety of nanofibers including polymers, carbon, ceramics, and composites with tunable diameters were fabricated at ultrahigh rates. The system can be further upgraded from single thread to multiple parallel threads and to the meshes, boosting the production of nanofibers to kilogram scale without compromising their quality.

Noise-induced quasiperiod and period switching.

We employ a typical genetic circuit model to explore how noise can influence dynamic structure. With the increase of a key interactive parameter, the model will deterministically go through two bifurcations and three dynamic structure regions. We find that a quasiperiodic component, which is not allowed by deterministic dynamics, will be generated by noise inducing in the first two regions, and this quasiperiod will be more and more stable along with the increase in noise. In particular, in the second region the quasiperiod will compete with a stable limit cycle and perform a new transient rhythm. Furthermore, we ascertain the entropy production rate and the heat dissipation rate, and discover a minimal value with theoretical elucidation. In the end, we unveil the mechanism of the formation of quasiperiods, and show a practical biological example. We expect this work to be helpful in solving some biological or ecological problems, such as the genetic origin of periodical cicadas and population dynamics with fluctuation.

Clinical characteristics and neuroimaging findings of seven patients with Dyke Davidoff Masson syndrome.

BACKGROUND: DDMS is a rare disease diagnosed by clinical and radiological characteristics. But the complexity of radiological and clinical manifestations of DDMS has become a challenge diagnostically. To date, the reported cases with DDMS had highly varied clinical manifestations including seizures, contralateral hemiplegia/hemiparesis, facial asymmetry, mental retardation, etc. In addition to typical clinical findings, some new characteristics have been recently added to the spectrum of DDMS. However, few cases have been reported to be associated with neuropsychiatric symptoms according to the literature. This study aimed to investigate the neuropsychiatric manifestations associated with Dyke-Davidoff-Masson syndrome (DDMS) and related imaging findings. METHODS: This study included 7 patients diagnosed with DDMS between 2014 and 2020. The clinical characteristics, neuropsychiatric manifestations, and radiological results were retrospectively evaluated. RESULTS: Seven patients (five males and two females) with a mean age of 28.0 ± 9.73 (range 15.0-41.0) years were included. Five patients were admitted to the psychiatric unit due to psychological and behavioral disorders. Two patients were referred to the neurology unit mainly due to epilepsy. Six patients had epileptic seizures, 4 had hemiplegia, 3 had mental retardation, 2 patients had external ear deformities, and 2 had facial asymmetry. Neuropsychiatric symptoms were presented in 6 (85.7 %) cases. Cases 2-6 developed affective disorders. Deficits in verbal communication, impairment of social interaction, lack of insight, adulia and hypobulia appeared in cases 1-4. Schizophrenia with apathy, and epileptic schizoid psychosis were observed in cases 4 and 5 respectively. Case 6 had behavioral disorders, hyperactivity, tic disorder, mental retardation, anxiety, catatonic symptoms and suicidal tendency. Case 7 had seizures and mental retardation, and no psychiatric symptoms were presented. Radiological examinations showed unilateral cerebral atrophy, enlarged lateral ventricles, and various compensatory hypertrophy of the skull in all cases. The midline structure has shifted to the affected side in 5(71.4 %) cases. Atrophy of the basal ganglia or brain stem was observed in 4(57.1 %) cases. CONCLUSIONS: The hallmark imaging manifestations of DDMS facilitated the diagnosis in most cases. This study illustrated that a variety of psychoneurotic disorders and ear abnormalities were correlated with DDMS.

Aberrant promoter methylation of T-cadherin in sera is associated with a poor prognosis in oral squamous cell carcinoma.

T-cadherin functions as a suppressor gene, which is frequently inactivated by aberrant promoter methylation in several human cancers, but its methylation status in oral squamous cell carcinoma (OSCC) has been scarcely studied. Thus this study aimed at exploring the clinical significance and prognostic value of T-cadherin methylation in sera of patients with OSCC. Methylation-specific PCR (MSP) and bisulfate sequencing PCR (BSP) was performed to examine the methylation status of T-cadherin. Then, the associations between methylation status of T-cadherin and various clinicopathological variables or patient survival were investigated in 202 patients with OSCC and 68 controls. T-cadherin methylation was detected in 62 out of 202 (30.7%) patients with OSCC, and the methylation status of T-cadherin in corresponding tissues was confirmed by BSP. Methylation of T-cadherin was significantly associated with advanced tumor T-stage (p<0.001) and N-stage (p=0.003), positive lymphatic metastasis (p=0.004) and tumor recurrence (p=0.001). In addition, patients with methylation of T-cadherin had worse overall survival (p=0.018) and progression-free survival (p<0.001) than patients without, and methylation of T-cadherin in sera was an independent prognostic factor for worse overall survival (HR: 3.626, 95% CI: 1.112-9.624, p=0.007) and progression-free survival (HR: 4.201, 95% CI: 1.562-10.038, p<0.001) of patients with OSCC. These results demonstrated that methylation of T-cadherin was frequently detected in sera of patients with OSCC, which was associated with risk factors of poor outcomes, and may act as a potential independent prognostic marker for patients with OSCC.

Pooled analysis of the Xpert MTB/RIF assay for diagnosing tuberculous meningitis.

BACKGROUND: Tuberculous meningitis (TBM) is one of the most serious types of extrapulmonary tuberculosis. However, low sensitivity of culture of cerebrospinal fluid (CSF) increases the difficulty in clinical diagnosis, leading to diagnostic delay, and misdiagnosis. Xpert MTB/RIF assay is a rapid and simple method to detect tuberculosis. However, the efficacy of this technique in diagnosing TBM remains unclear. Therefore, a meta-analysis was conducted to evaluate the diagnostic efficacy of Xpert MTB/RIF for TBM, which may enhance the development of early diagnosis of TBM. METHODS: Relevant studies in the PubMed, Embase, and Web of Science databases were retrieved using the keywords 'Xpert MTB/RIF', 'tuberculous meningitis (TBM)'. The pooled sensitivity, pooled specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, summary receiver operator characteristic curve, and area under the curve (AUC) of Xpert MTB/RIF were determined and analyzed. RESULTS: A total of 162 studies were enrolled and only 14 met the criteria for meta-analysis. The overall pooled sensitivity of Xpert MTB/RIF was 63% [95% confidence interval (CI), 59-66%], while the overall pooled specificity was 98.1% (95% CI, 97.5-98.5%). The pooled values of positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 20.91% (12.71-52.82%), 0.40% (0.32-0.50%), and 71.49% (32.64-156.56%), respectively. The AUC was 0.76. CONCLUSIONS: Xpert MTB/RIF exhibited high specificity in diagnosing TBM in CSF samples, but its sensitivity was relatively low. It is necessary to combine other high-sensitive detection methods for the early diagnosis of TBM. Moreover, the centrifugation of CSF samples was found to be beneficial in improving the sensitivity.

Preoperative high c-reactive protein/albumin ratio is a poor prognostic factor of oral squamous cell carcinoma.

Aim: To explore whether c-reactive protein/albumin (CRP/Alb) ratio is a poor prognostic factor for patients with oral squamous cell carcinoma (OSCC). Patients & methods: Receiver-operating characteristic analysis was performed to evaluate the optimal cut-off value of CRP/Alb ratio in 240 patients with OSCC. The Kaplan-Meier method was used to plot the overall survival and disease-free survival curves. Cox proportional hazards model was used to implement univariate and multivariate analyses. Results: Preoperative high CRP/Alb ratio was associated with age, advanced stage, lymphatic metastasis, platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio (all p < 0.05). Elevated CRP/Alb ratio independently predicts worse overall survival and disease-free survival of patients with OSCC. Conclusion: Preoperative high CRP/Alb ratio was a poor independent prognostic marker of OSCC.

4-NBT, a specific inhibitor of Babesia microti thioredoxin reductase, affects parasite biochemistry and proteomic properties.

Babesia microti is an emerging zoonotic pathogen that is transmitted by ticks and parasites and propagates in mammalian erythrocytes. Thioredoxin reductase (TrxR) plays a crucial role in B. microti survival by maintaining cellular redox homeostasis. In the present study, 4-nitro-2,1,3-benzothiadiazole (4-NBT) was selected as a specific B. microti TrxR inhibitor by comparing rat and parasite TrxR inhibition levels. Reactive oxygen species (ROS) levels were evaluated using flow cytometry, and in B. microti treated with 4-NBT, ROS levels increased with increasing inhibitor concentration. Furthermore, the inhibitor treatment increased lipid peroxidation and protein carbonyl levels, thus indicating a state of oxidative stress. While B. microti treated with 4-NBT appeared to lose the ability to multiply in mice, the fastigium of parasitemia between the treated and control groups was comparable. Furthermore, a TUNEL assay showed that 4-NBT induces apoptosis in B. microti. Proteomic analysis of B. microti treated with 4-NBT detected 960 proteins. Label-free quantitative proteomic analysis identified 118 proteins that were significantly up-regulated and 37 that were significantly down-regulated in the treatment group relative to the control. Of the differential proteins, proteasome and ribosomal subunit expression was up-regulated, thus suggesting that redundant proteins may be damaged by oxidation and waiting for degradation, while proteins for subsistence are waiting for de novo synthesis. Moreover, the findings obtained herein suggest that the DNA and lipids were also damaged and awaiting synthesis or repair. In conclusion, TrxR dysfunction in B. microti results in the breakdown of redox homeostasis and promotes apoptosis.

Piezoelectric and polarized enhancement by hydrofluorination of penta-graphene.

Motivated by the challenges in the harnessing of energy and the continuing trend of miniaturizing devices, an exhaustive evaluation of the electronic, mechanical and piezoelectric properties of surface modified penta-graphene (PG), including fluorinated PG (F-PG-F), hydrofluorinated PG (H-PG-F) and hydrogenated PG (H-PG-H), was carried out via a first-principles approach based on density functional theory. We first predicted the H-PG-F system and calculated its phonon dispersion and magnetic properties. All three systems were found to exhibit an e31 piezoelectric effect, and the e31 (96.88 pC m-1) effect of H-PG-F was found to be much greater than that of the other two systems. So, it could be concluded that hydrofluorination can significantly enhance the piezoelectric properties of PG. The binding energy and formation energy of the H-PG-F system were found to be the lowest among the three surface modified PG systems, showing that the H-PG-F system is the most energetically favorable state. The e31 piezoelectricity can be potentially engineered into a PG monolayer by surface modification, providing an avenue for monolithic integration of electronic and electromechanical devices with a PG monolayer for use in mechanical stress-sensors, nano-sized actuators and energy harvesting systems. The H-PG-F system stands out in terms of its combination of a larger piezoelectric coefficient (e31 = 96.88 pC m-1), negative Poisson's ratio and low formation energy (-3.37 eV) and is recommended for experimental exploration.

Babesia microti thioredoxin 3 is an effective antioxidant and involved in the response to antiprotozoal drugs.

The intra-erythrocytic apicomplexan Babesia microti is the predominant pathogen that causes human babesiosis, an infectious disease that occurs worldwide. B. microti relies on the antioxidant including thioredoxin system to maintain the redox balance during the erythrocytic stage. In the present study, the full-length B. microti thioredoxin 3 (BmTrx3) gene was cloned, expressed in vitro, and its response to antiprotozoal drugs were tested. The full-length BmTrx3 was 663 bp and contained an intact open reading frame of 567 bp. The encoded polypeptide was 188 amino acids and the predicted molecular weight of the protein was 21.7 kDa. A conserved thioredoxin-like family domain was found in BmTrx3. The expression of BmTrx3 was upregulated on both the third and eighth day post-infection in mice, whereas expression was downregulated during the beginning and later stages. Western blot analysis showed that mouse anti-BmTrx3 serum could recognize the native BmTrx3 in parasite lysates and that the mouse anti-B. microti serum could recognize the recombinant BmTrx3 protein. Immunofluorescence microscopy showed that BmTrx3 localized in the cell cytoplasm of B. microti merozoites in B. microti-infected red blood cells. The results of bovine insulin reduction assay indicated the enzyme activity of the purified recombinant BmTrx3 protein. The anti-malaria drug chloroquine significantly inhibited the expression of BmTrx3, however, another anti-malaria drug qunine, and a known anti-babesiosis drug clindamycin, induced significantly higher upregulation of BmTrx3 mRNA. The results of the present study demonstrate that BmTrx3 is a functional enzyme with antioxidant activity and may be involved in the response of B. microti to anti-parasite drugs.

Molecular characterization of Babesia microti thioredoxin (BmTrx2) and its expression patterns induced by antiprotozoal drugs.

BACKGROUND: Human babesiosis is an infectious disease that is epidemic in various regions all over the world. The predominant causative pathogen of this disease is the intra-erythrocytic parasite Babesia microti. The thioredoxin system is one of the major weapons that is used in the resistance to the reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced by host immune system. In other intra-erythrocytic apicomplexans like the malaria parasite Plasmodium falciparum, anti-oxidative proteins are promising targets for the development of anti-parasitic drugs. However, to date, the sequences and biological properties of thioredoxins and thioredoxin-like molecules of B. microti remain unknown. Understanding the molecular characterization and function of B. microti thioredoxins may help to develop anti-Babesia drugs and controlling babesiosis. METHODS: The full-length B. microti thioredoxin 2 (BmTrx2) gene was obtained using a rapid amplification of cDNA ends (RACE) method, and the deduced BmTrx2 amino acid sequence was analyzed using regular bioinformatics tools. Recombinant BmTrx2 protein was expressed in vitro and purified using His-tag protein affinity chromatography resins. Reverse transcription PCR, quantitative real-time PCR and Western blot were employed to detect the expression and native proteins of BmTrx2. Indirect immunofluorescence assay was used to localize BmTrx2 in B. microti. Bovine insulin reduction assays were used to determine the enzyme activity of the purified recombinant BmTrx2 protein. RESULTS: The full-length BmTrx2 was 564 bp with a 408 bp open reading frame encoding a protein of 135 amino acids. The predicted molecular weight of the protein was 15.5 kDa. A conserved thioredoxin-like family domain was found in BmTrx2. The expression of BmTrx2 was upregulated on both the third and eighth day post-infection in mice, whereas expression was downregulated during the beginning and later stages. The results of Western blot analysis showed the native BmTrx2 in parasite lysates could be detected by mouse anti-BmTrx2 serum and that the recombinant BmTrx2 protein could be recognized by serum of B. microti-infected mice. Immunofluorescence microscopy showed that BmTrx2 localized in the cell cytoplasm of B. microti merozoites in B. microti-infected red blood cells. The results of bovine insulin reduction assay indicated the purified recombinant BmTrx2 protein possesses antioxidant enzyme activity. Dihydroartemisinin and quinine, known anti-malaria drugs, and clindamycin, a known anti-babesiosis drug, induced significantly higher upregulation of BmTrx2 mRNA. CONCLUSIONS: Our results indicate that BmTrx2 is a functional enzyme with antioxidant activity and may be involved in the response of B. microti to anti-parasite drugs.