Increased indexed proximal aortic diameter is a predictor of poor prognosis in maintenance hemodialysis patients.

Background: Recent studies have shown that the baseline values of absolute aortic root diameter (ARD) and indexed diameter are associated with all-cause mortality and cardiovascular events in the general population, even in the absence of aneurysmal aortic disease. However, there is limited available data on the association between ARD and prognosis in end-stage renal disease (ESRD) patients receiving maintenance hemodialysis (MHD). Accordingly, the purpose of this study is to investigate the predictive value of ARD for all-cause mortality and cardiovascular events in this specific population.Methods: ARD was measured by echocardiography at the level of the sinuses of Valsalva at end diastole and indexed to body surface area (BSA). The primary endpoint was all-cause mortality. The secondary endpoint was major adverse cardiovascular events (MACE), including cardiovascular mortality, myocardial infarction and stroke. Cox proportional hazards models were conducted to evaluate the association between baseline ARD/BSA and clinical outcomes.Results: A total of 391 patients were included in this study. The primary endpoint occurred in 95 (24.3%) patients while the secondary endpoint occurred in 71 (18.2%) patients. Multivariate Cox regression analysis showed that ARD/BSA was an independent prognostic factor for all-cause mortality (HR, per 1-SD increase, 1.403; 95% CI, 1.118-1.761; p = 0.003) as well as MACE (HR, per 1-SD increase, 1.356; 95% CI, 1.037-1.772; p = 0.026).Conclusions: Our results show that ARD/BSA is predictive of all-cause mortality and MACE in MHD patients with ESRD and support the view that assessment of ARD/BSA may refine risk stratification and preventive strategies in this population.

Cell recognition based on atomic force microscopy and modified residual neural network.

Cell recognition methods are in high demand in cell biology and medicine, and the method based on atomic force microscopy (AFM) shows a great value in application. The difference in mechanical properties or morphology of cells has been frequently used to detect whether cells are cancerous, but this detection method cannot be a general means for cancer cell detection, and the traditional artificial feature extraction method also has its limitations. In this work, we proposed an analytic method based on the physical properties of cells and deep learning method for recognizing cell types. The residual neural network used for recognition was modified by multi-scale convolutional fusion, attention mechanism and depthwise separable convolution, so as to optimize feature extraction and reduce operation costs. In the method, the collected cells were imaged by AFM, and the processed images were analyzed by the optimized convolutional neural network. The recognition results of two groups of cells (HL-7702 and SMMC-7721, SGC-7901 and GES-1) by this method show that the recognition rate of dataset with the combination of cell surface morphology, adhesion and Young's modulus is higher, and the recognition rate of the dataset with optimal resolution is higher. Our study indicated that the recognition of physical properties of cells using deep learning technology can serve as a universal and effective method for the automated analysis of cell information.

Drug repurposing for COVID-19: could vitamin C combined with glycyrrhizic acid be at play by the findings of Li et al.'s database-based network pharmacology analysis?

The outbreak and pandemic of SARS-CoV-2 in 2019 has caused a severe public health burden and will challenge global health for the future. The discovery and mechanistic investigation of drugs against Coronavirus disease 2019 (COVID-19) is in deadly demand. The paper published by Li and colleagues proposed the hypothesis that vitamin C combined with glycyrrhizic acid in treating COVID-19 and its mechanistic investigation was performed by a database-based network pharmacology. In this letter, we present critical comments on the limitations and insufficiencies involved, from both the perspective of network pharmacology and current evidence on COVID-19.

Overexpression of POLA2 in hepatocellular carcinoma is involved in immune infiltration and predicts a poor prognosis.

BACKGROUND: Hepatocellular carcinoma (HCC) is the second malignancy worldwide. POLA2 initiates DNA replication, regulates cell cycle and gene repair that promote tumorigenesis and disease progression. However, the prognostic and biological function roles of POLA2 in HCC had not been conclusively determined. METHODS: The expression levels and prognosis role of POLA1 and POLA2 in HCC were analyzed based on TCGA-LIHC database and recruited 24 HCC patients. Gene mutations were analyzed using "maftools" package. POLA2 and immune cells correlations were analyzed by TIMER. POLA2 co-expressed genes functional enrichment were evaluated using Metascape. The mRNA and protein level of POLA2 was detected in HCC cells and tissues. Cell migration, invasion, proliferation, cell cycle and HCC cell lines derived xenograft model were performed to investigate POLA2 biological function. RESULTS: POLA2 was significantly high expressed in HCC than in normal liver tissue in both TCGA-LIHC and our collected HCC samples. In validation cohort, POLA2 significantly related to tumor differentiation, tumor size and Ki-67 (p < 0.05). In TCGA-LIHC cohort, overexpression of POLA2 predicted a low OS and associated with different clinical stages. Multivariate Cox regression showed overexpression of POLA2 effectively distinguished the prognosis at different T, N, M, stages and grades of HCC. POLA2 expression correlated with mutation burden, immune cells infiltration and immune-associated genes expression of HCC. Functional enrichment revealed that POLA2 co-expressed genes were linked to cellular activity, plasma membrane protein complex and leukocyte activity, immune response-regulated cell surface receptor signaling pathway, and immune response-regulated signaling pathway. Moreover, POLA2 was also positively co-expressed with some immune checkpoints (CD274, CTL-4, HAVCR2, PDCD1, PDCD1LG2, TIGIT, and LAG3) (p < 0.001). Gene knockdown revealed that POLA2 promoted proliferation, migration, invasion, and cell cycle of SMMC-7721 and HepG2. The HCC xenograft tumor model also demonstrated remarkably tumor size inhibition, tumor proliferation inhibtion and tumor necrosis promotion when POLA2 knockdown. CONCLUSIONS: POLA2 influenced immune microenvironment and tumor progression of HCC indicated that it might be a potential molecular marker for prognostic evaluation or a therapeutic target for HCC.

Isolated cryptococcal osteomyelitis of the sacrum in an immunocompetent patient: a case report and literature review.

BACKGROUND: Cryptococcus neoformans, an opportunistic fungal pathogen, seldom causes infection in immunocompetent people. Cryptococcal osteomyelitis is an uncommon condition in which Cryptococcus invades the bone. It usually occurs as part of a disseminated infection and rarely in isolation. The spine has been reported as the most common site of cryptococcal osteomyelitis; however, isolated case of sacrum involvement in immunocompetent patients has never been reported. CASE PRESENTATION: We report the case of a 37-year-old man without underlying disease who presented with progressive low back and sacrococcygeal pain. The patient was initially diagnosed with sacral tumour by a local doctor, and subsequently, after admission, was diagnosed with sacral tuberculosis. He was empirically treated with antitubercular drugs. The patient failed to respond to antitubercular drugs and complained of worsening low back pain. Additionally, he developed persistent radiating pain and numbness in his legs. For further diagnosis, we performed a computed tomography-guided puncture biopsy of the sacrum, which revealed granulomatous inflammation with massive macrophage infiltration and special staining revealed a fungal infection. We performed sacral debridement and drainage and obtained purulent specimens for pathological examination and microbial culture. Microbial identification and drug susceptibility tests revealed a Cryptococcus neoformans infection sensitive to fluconazole. Postoperatively, the persistent radiating pain and numbness in the legs resolved. After 12 consecutive weeks of antifungal therapy, all his symptoms resolved. The patient remained without any signs of recurrence at the 8-month follow-up. CONCLUSION: We reported a rare case of isolated sacrum cryptococcal osteomyelitis in an immunocompetent patient. Furthermore, we identified and reviewed 18 published cases of spine cryptococcal osteomyelitis. Immunocompetent individuals are also at risk for cryptococcal osteomyelitis. Clinical manifestation and imaging are insufficient to diagnose cryptococcal osteomyelitis of the spine, and invasive examinations, such as puncture biopsy and fungal examinations, are needed. Antifungal therapy yields satisfactory results for the treatment of cryptococcal osteomyelitis of the spine, however, if the infective lesion is large, especially when it compresses the spinal cord and nerves, a regimen combining aggressive surgery with antifungal therapy is indispensable.

Correlation between urine vitamin D-binding protein and early-stage renal damage in Type 2 diabetes. / å°¿ç»´ç”Ÿç´ D结合蛋白与2åž‹ç³–å°¿ç— æ‚£è€ æ—©æœŸè‚¾æŸå®³çš„ç›¸å ³æ€§.

OBJECTIVES: The excretion of urinary vitamin D-binding protein (uVDBP) is related to the occurrence and development of early-stage renal damage in patients with Type 2 diabetes (T2DM). This study aims to explore the significance of detecting uVDBP in T2DM patients and its relationship with renal tubules, and to provide a new direction for the early diagnosis of T2DM renal damage. METHODS: A total of 105 patients with T2DM, who met the inclusion criteria, were included as a patient group, and recruited 30 individuals as a normal control group. The general information and blood and urine biochemical indicators of all subjects were collected; the levels of uVDBP, and a marker of tubular injury [urine kidney injury molecule 1 (uKIM-1), urine neutrophil gelatinase-associated lipocalin (uNGAL) and urine retinol-binding protein (uRBP)] were detected by enzyme-linked immunosorbent assay. The results were corrected by urinary creatinine (Cr) to uVDBP/Cr, uKIM-1/Cr, uNGAL/Cr and uRBP/Cr. The Pearson's and Spearman's correlation tests were used to analyze the correlation between uVDBP/Cr and urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR) and markers of tubular injury, and multivariate linear regression and receiver operating characteristic curve were used to analyze the correlation between uVDBP/Cr and UACR or eGFR. RESULTS: Compared with the normal control group, the uVDBP/Cr level in the patient group was increased (P<0.05), and which was positively correlated with UACR (r=0.774, P<0.01), and negatively correlated with eGFR (r=-0.397, P<0.01). There were differences in the levels of uKIM-1/Cr, uNGAL/Cr, and uRBP/Cr between the 2 groups (all P<0.01). The uVDBP/Cr was positively correlated with uKIM-1/Cr (r=0.752, P<0.01), uNGAL/Cr (r=0.644, P<0.01) and uRBP/Cr (r=0.812, P<0.01). The sensitivity was 90.0% and the specificity was 82.9% (UACR>30 mg/g) for evaluation of uVDBP/Cr on T2DM patients with early-stage renal damage, while the sensitivity was 75.0% and the specificity was 72.6% for evaluation of eGFR on T2DM patients with early-stage renal damage. CONCLUSIONS: The uVDBP/Cr can be used as a biomarker in early-stage renal damage in T2DM patients.

Expanding the Scope of Targeted Metabolomics by One-pot Microscale Synthesis and Tailored Metabolite Profiling: Investigation of Bile Acid-Amino Acid Conjugates.

Accurate metabolite characterization plays a vital role in targeted metabolomics. Nonetheless, the library of metabolites is still limited, especially for downstream conjugates, and it is time-consuming to synthesize each of these compounds due to high structural diversity. Herein, a green and smart strategy was developed to expand the scope of targeted metabolomics. The reference standards were synthesized in a one-pot microscale reaction, and the analytical method was tailored using the synthetic products. A group of new metabolites, namely bile acid-amino acid conjugates (BA-AAs), was studied as a proof-of-concept. First, in total 160 BA-AAs were synthesized using a small amount (2 mg each) of bile acids and low-toxic reagents within 4 h. Then, an ultra-high-performance liquid chromatography /Orbitrap-MS method was established to comprehensively profile 202 bile acid derivatives in 20 min. Finally, the method was applied to mice with inflammatory bowel disease (IBD) to discover the accumulation of 70 rare BA-AAs in small intestine and liver, where 55 were first reported from biosamples. These BA-AAs are farnesoid X receptor modulators and might contribute to the development of IBD. Our study demonstrated a feasible approach for the broad-spectrum targeted metabolomics of bile acids.

Misdiagnosis of brown tumour caused by primary hyperparathyroidism: a case report with literature review.

BACKGROUND: Brown tumour is a rare tumour-like lesion of the bone, which is considered as an end-stage lesion of abnormal bone metabolism caused by persistently high parathyroid hormone (PTH) levels. Brown tumour can be found in any part of the skeleton; in some cases, it can occur in multiple bones and can be easily misdiagnosed as a metastatic tumour. CASE PRESENTATION: We report the case of a 44-year-old man who presented to the Department of Oncology in our hospital with a 2-month history of local pain in his left shoulder joint. The initial diagnosis was an aneurysmal bone cyst by biopsy, for which the patient underwent tumour resection surgery. The diagnosis of a malignant tumour was made again following postoperative pathological examination. The pathological sections and all clinical data were sent to the Department of Pathology of the First Affiliated Hospital of Sun Yat-sen University; the diagnosis made there was brown tumour. His blood PTH level was 577 pg/ml (15-65 pg/ml). Colour Doppler ultrasonography of the parathyroid gland suggested a parathyroid adenoma. For further treatment, the left parathyroid adenoma was removed by axillary endoscopic resection. Postoperatively, a pathologic examination was performed, and the diagnosis of a parathyroid adenoma was confirmed. One year after the surgery, the left humerus was completely healed, and the left shoulder joint had a good range of movement. CONCLUSIONS: In summary, histopathological diagnosis is not sufficient for the diagnosis of brown tumours. A comprehensive analysis combining clinical symptoms with findings of imaging and laboratory tests is also required. Generally, the treatment of brown tumour includes only partial or complete resection of the parathyroid glands. However, when the tumour is large, especially when it involves the joint, surgery is indispensable.

Effect of docetaxel on mechanical properties of ovarian cancer cells.

Docetaxel could inhibit the proliferation of tumor cells by targeting microtubules. The extension of cellular microtubules plays an important role in the invasion and metastasis of tumor cells. This paper aims to study the distribution and mechanical properties of cytoskeletal proteins with low concentration of docetaxel. MTT assay was used to detect the minimum drug activity concentration of docetaxel on SKOV-3 cells, fluorescence staining was used to analyze the distribution of cytoskeleton proteins, scanning electron microscopy(SEM) was used to observe the morphology of single cells, and atomic force microscopy(AFM) was used to determine the microstructure and mechanical properties of cells. The results showed that the IC10 of docetaxel was 1 ng/ml. Docetaxel can effectively inhibit the formation of cell pseudopodia, hinder the indirectness between cells, reduce the cell extension area, and make the cells malformed. In addition, when AFM analyzes the effects of drugs on cell microstructure and mechanical properties, the average cell surface roughness and cell height are positively correlated with the concentration of docetaxel. Especially when the concentration was 100 ng/ml, the adhesion decreased by 37.04% and Young's modulus increased by 1.57 times compared with the control group. This may be because docetaxel leads to microtubule remodeling and membrane protein aggregation, which affects cell microstructure and increases cell strength, leading to significant changes in the mechanical properties of ovarian cells. This is of great significance to the study of the formation mechanism of tumor cell invasion and migration activities mediated by actin.

The antithrombosis effect of dehydroandrographolide succinate: in vitro and in vivo studies.

CONTEXT: Dehydroandrographolide succinate (DAS) is mainly used in the clinical treatment of various infectious diseases. Its potential effects on platelet aggregation and blood coagulation systems have not been reported systematically. OBJECTIVE: To explore whether DAS exerts an antithrombotic effect and its internal mechanism. MATERIALS AND METHODS: Human blood samples and Sprague-Dawley (SD) rats divided into control, aspirin (30 mg/kg), and DAS groups (200, 400 and 600 mg/kg) were used to measure the platelet aggregation rate, coagulation function, coagulation factor activity, and contents of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1α (6-keto-PGF1α). The histopathology of the SD rat gastric mucosa was also observed. All rats were administered intragastric or intraperitoneal injections once a day for 3 consecutive days. RESULTS: Compared to control group, DAS significantly inhibited the platelet aggregation rate (ED50 = 386.9 mg/kg) by decreasing TXB2 levels (1531.95 ± 649.90 pg/mL to 511.08 ± 411.82 pg/mL) and activating antithrombin III (AT-III) (103.22 ± 16.22% to 146.46 ± 8.96%) (p < 0.05). In addition, DAS significantly enhanced the coagulation factors FV (304.12 ± 79.65% to 443.44 ± 75.04%), FVII (324.19 ± 48.03% to 790.66 ± 225.56%), FVIII (524.79 ± 115.47% to 679.92 ± 143.34%), FX (34.90 ± 7.40% to 102.76 ± 29.41%) and FXI (38.12 ± 10.33% to 65.47 ± 34.08%), increased the content of Fg (2.18 ± 0.39 to 3.61 ± 0.37 g/L), shorten the PT (10.42 ± 0.44 to 9.22 ± 0.21 s), APTT (16.43 ± 1.4 to 14.07 ± 0.75 s) and TT time (37.04 ± 2.13 to 32.68 ± 1.29 s) (p < 0.05), while the aspirin group showed no such effect on these items but showed reduced activity of FII (89.21 ± 21.72% to 61.83 ± 8.95%) and FVIII (524.79 ± 115.47% to 306.60 ± 29.96%) (p < 0.05). Histopathological changes showed aspirin-induced gastric mucosa haemorrhage and the protective effect of DAS in the gastric mucosa. CONCLUSIONS: DAS is more suitable than aspirin in thromboprophylaxis treatment, which provides a reliable theoretical and experimental basis for its clinical application.

Vacant Manganese-Based Perovskite Fluorides@Reduced Graphene Oxides for Na-Ion Storage with Pseudocapacitive Conversion/Insertion Dual Mechanisms.

Na-ion capacitors (NICs) and Na-based dual-ion batteries (Na-DIBs) have been considered to be promising alternatives to traditional lithium-ion batteries (LIBs) because of the abundance and low cost of the Na-ion, but their energy density, power density and life cycle are limited. Herein, dual-vacancy (including K+ and F- vacancies) perovskite fluoride K0.86 MnF2.69 @reduced graphene oxide (rGO; recorded as Mn-G) as anode for NICs and Na-DIBs has been developed. The special conversion/intercalation dual Na-ion energy storage mechanism and pseudocapacitive dynamics are analyzed in detail. The Mn-G//AC NICs and Mn-G//KS6 Na-DIBs delivered a maximum energy density of 92.7 and 187.6 W h kg-1 , a maximum power density of 20.2 and 21.12 kW kg-1 , and long cycle performance of 61.3 and 68.4 % after 1000 cycles at 5 A g-1 , respectively. Moreover, Mn-G//AC NICs and Mn-G//KS6 Na-DIBs can work well over a wide range of temperatures (-20 to 40 °C). These results make it competitive in Na-ion storage applications with high energy/power density over a wide temperature range.

[Identification of quality markers of Qixuehe Capsules based on analytic hierarchy process and entropy weight methods].

Qixuehe Capsules is a compound Chinese patent medicine developed for treating the disorder of Qi and blood(a common etiology of gynecological disease), which has remarkable effects on smoothing liver and regulating Qi, activating blood circulation, and relieving pain. However, due to its complex prescriptions(15 herbs) and multiple effects, the quality control of Qixuehe Capsules has always been a bottleneck problem limiting its sustainable development. Therefore, this study adopted the traditional Chinese medicine Q-markers quantitative identification system established previously by our research group based on the combination of analytic hierarchy process and entropy weight methods. With the different effects of Qixuehe Capsules as the entry point, the comprehensive scores of chemical ingre-dients in Qixuehe Capsules under the items of effectiveness(smoothing liver and regulating qi, activating blood circulation, and relieving pain), testability and specificity were calculated and integrated, respectively. Subsequently, through the analysis of compatibility relationship of Qixuehe Capsules, 15 active ingredients with high comprehensive scores were found to be the top Q-mar-kers of Qixuehe Capsules, including ferulic acid, quercetin, caffeic acid, kaempferol, rutin, Z-ligustilide, senkyunolide Ⅰ, vanillic acid, protocatechuic acid, chlorogenic acid, rosmarinic acid, senkyunolide A, gallic acid, tetrahydropalmatine and eugenol. Collectively, this study not only provided scientific evidence for further research on the improvement and standardization of quality standards of Qixuehe Capsules but also provided methodological references for the quantitative identification of Q-markers of multi-effect traditional Chinese medicine formulae.

Conversion/Alloying Pseudocapacitance-Dominated Perovskite KZnF3 Anode for Advanced Lithium-Based Dual-Ion Batteries.

Cost-competitive perovskite fluoride KZnF3 has been introduced for the first time as an advanced anode for high-performance lithium-based dual-ion batteries, exhibiting conversion/alloying hybrid mechanisms and dominated pseudocapacitive kinetics for Li-ion storage.

Recombinant expression and functional analysis of antimicrobial Siganus oraminl-amino acid oxidase using the Bac-to-Bac baculovirus expression system.

Siganus oraminl-amino acid oxidase (SR-LAAO), isolated from the serum of Siganus oramin, is an innate immune protein with significant antibacterial activity. The aim of this study was to express SR-LAAO in insect cells using a baculovirus expression system and evaluate the function of the recombinant SR-LAAO. To this end, an optimized sequence of the SR-LAAO gene was designed and synthesized, based on the codon bias of insect cells. Bacmid shuttle vectors and recombinant baculovirus were successfully constructed, and the recombinant baculovirus was transfected into Sf9 insect cells. The antibacterial activity and enzymatic characteristics of the recombinant SR-LAAO were investigated. The results showed that the pFastBac-optiSR-LAAO shuttle vectors and Bacmid-optiSR-LAAO were correctly constructed. The Sf9 insect cells exhibited significant cytopathic effects following infection with Bacmid-optiSR-LAAO and Bacmid; the specific PCR analysis proved that the recombinant baculovirus was successfully constructed. The immunofluorescence assay revealed that the recombinant baculovirus rSR-LAAO was abundantly expressed in infected Sf9 insect cells; the results of SDS/PAGE and Western blot analyses showed that a specific band appeared at about 60 kDa. Moreover, the crude rSR-LAAO enzyme displayed strong antibacterial activity against aquatic pathogens, particularly Streptococcus agalactiae and Streptococcus iniae. In addition, the results of catalase interference test implied that the antibacterial activity of rSR-LAAO was directly associated with (H2O2 production). The results of the rSR-LAAO enzymatic characteristics test indicated that the Km value with l-Lysine as a substrate was 16.61 mM when the temperature was under 37 °C, and the optimum pH was 7. The antibacterial activity of rSR-LAAO could be completely inhibited by 10 mg/mL of pepsin, trypsin, and proteinase K compared with both methanol and acetone. Adding an equal volume of ethanol had a minimal impact on the antibacterial activity of rSR-LAAO. The crude enzyme could maintain a high level of antibacterial activity against both Gram-positive and -negative bacteria from 4 °C to 30 °C. In the present study, SR-LAAO was successfully expressed in Sf9 cells using the baculovirus expression system, and provides basic references for further research into the role of LAAO in marine animals and the development of new antimicrobial drugs.

Novel Janus Membrane for Membrane Distillation with Simultaneous Fouling and Wetting Resistance.

A novel Janus membrane integrating an omniphobic substrate and an in-air hydrophilic, underwater superoleophobic skin layer was developed to enable membrane distillation (MD) to desalinate hypersaline brine with both hydrophobic foulants and amphiphilic wetting agents. Engineered to overcome the limitations of existing MD membranes, the Janus membrane has been shown to exhibit novel wetting properties unobserved in any existing membrane, including hydrophobic membranes, omniphobic membranes, and hydrophobic membranes with a hydrophilic surface coating. Being simultaneously resistant to both membrane fouling and wetting, a Janus membrane can sustain stable MD performance even with challenging feed waters and can thus potentially transform MD to be a viable technology for desalinating hypersaline wastewater with complex compositions using low-grade-thermal energy.

Synthesis of BiOClx Br1-x Nanoplate Solid Solutions as a Robust Photocatalyst with Tunable Band Structure.

The use of bismuth oxyhalides as photocatalysts has received extensive interest because of their high photocatalytic activity and stability. However, available methods for the synthesis of bismuth oxyhalides with tailored morphologies, well-defined facets, and tunable band gaps are still lacking. In this work, two-dimensional BiOClx Br1-x solid solution with exposed {001} facets and tunable band gaps were synthesized by using solvothermal methods. The BiOClx Br1-x solid solution nanoplates crystallized in a homogeneous crystal structure but possessed continuously tuned band gaps from 3.39 to 2.78 eV by decreasing the ratio of Cl/Br. Among the synthesized nanoplates, the BiOCl0.5 Br0.5 sample exhibited the highest photocatalytic activity for degrading Rhodamine B (RhB), a typical organic pollutant, under visible light. The highest photoactivity of the BiOCl0.5 Br0.5 sample was attributed to a synergetic effect of higher surface area, facets exposed, and optimized band structure. The results are of profound significance for the design of novel photocatalyst materials.

Light-driven microbial dissimilatory electron transfer to hematite.

The ability of dissimilatory metal-reducing microorganisms (DMRM) to conduct extracellular electron transfer with conductive cellular components grants them great potential for bioenergy and environmental applications. Crystalline Fe(III) oxide, a type of widespread electron acceptor for DMRM in nature, can be excited by light for photocatalysis and microbial culture-mediated photocurrent production. However, the feasibility of direct electron transfer from living cells to light-excited Fe(III) oxides has not been well documented and the cellular physiology in this process has not been clarified. To resolve these problems, an electrochemical system composed of Geobacter sulfurreducens and hematite (α-Fe2O3) was constructed, and direct electron transfer from G. sulfurreducens cells to the light-excited α-Fe2O3 in the absence of soluble electron shuttles was observed. Further studies evidenced the efficient excitation of α-Fe2O3 and the dependence of photocurrent production on the biocatalytic activity. Light-induced electron transfer on the cell-α-Fe2O3 interface correlated linearly with the rates of microbial respiration and substrate consumption. In addition, the G. sulfurreducens cells were found to survive on light-excited α-Fe2O3. These results prove a direct mechanism behind the DMRM respiration driven by photo-induced charge separation in semiconductive acceptors and also imply new opportunities to design photo-bioelectronic devices with living cells as a catalyst.

Monodisperse M(x)Fe(3-x)O4 (M = Fe, Cu, Co, Mn) nanoparticles and their electrocatalysis for oxygen reduction reaction.

Sub-10 nm nanoparticles (NPs) of M(II)-substituted magnetite MxFe3-xO4 (MxFe1-xO•Fe2O3) (M = Mn, Fe, Co, Cu) were synthesized and studied as electrocatalysts for oxygen reduction reaction (ORR) in 0.1 M KOH solution. Loaded on commercial carbon support, these MxFe3-xO4 NPs showed the M(II)-dependent ORR catalytic activities with MnxFe3-xO4 being the most active followed by CoxFe3-xO4, CuxFe3-xO4, and Fe3O4. The ORR activity of the MnxFe3-xO4 was further tuned by controlling x and MnFe2O4 NPs were found to be as efficient as the commercial Pt in catalyzing ORR. The MnFe2O4 NPs represent a new class of highly efficient non-Pt catalyst for ORR in alkaline media.

Density functional theory study on the formation mechanism and electrical properties of two-dimensional electron gas in biaxial-strained LaGaO 3 /BaSnO 3 heterostructure.

The two-dimensional electron gas (2DEG) in BaSnO 3 -based heterostructure (HS) has received tremendous attention in the electronic applications because of its excellent electron migration characteristic. We modeled the n-type (LaO) + /(SnO 2 ) 0 interface by depositing LaGaO 3 film on the BaSnO 3 substrate and explored strain effects on the critical thickness for forming 2DEG and electrical properties of LaGaO 3 /BaSnO 3 HS system using first-principles electronic structure calculations. The results indicate that to form 2DEG in the unstrained LaGaO 3 /BaSnO 3 HS system, a minimum thickness of approximately 4 unit cells of LaGaO 3 film is necessary. An increased film thickness of LaGaO 3 is required to form the 2DEG for -3%-biaxially-strained HS system and the critical thickness is 3 unit cells for 3%-baxially-strained HS system, which is caused by the strain-induced change of the electrostatic potential in LaGaO 3 film. In addition, the biaxial strain plays an important role in tailoring the electrical properties of 2DEG in LaGaO 3 /BaSnO 3 HS syestem. The interfacial charge carrier density, electron mobility and electrical conductivity can be optimized when a moderate tensile strain is applied on the BaSnO 3 substrate in the ab-plane.