Display omitted
•h-BN/flower-ring g-C3N4 heterojunction photocatalyst was synthesized.•The surface area of the catalyst was markedly increased by morphology engineering.•Characterizations and DFT ...calculations confirmed a type-II heterojunction.•Built-in electric field enabled effective separation of photogenerated carriers.•The BM-5 photocatalyst has remarkable photoelectric properties.
Morphology adjustment and semiconductor coupling have great potential in effectively improving the photocatalytic activity of graphite carbon nitride (g-C3N4). Herein, an advanced heterostructure photocatalyst constructed by hexagonal boron nitride (h-BN) and flower-ring g-C3N4 (MCN) was successfully synthesized. Combining experiments and density functional theories (DFT) calculation, the photocatalytic process and charge transfer mechanism of h-BN/flower-ring g-C3N4 (BM) heterojunction were deeply studied. MCN had a large specific surface area, which increased the light absorption area and facilitated the exposure of active sites. Through the calculation of work function and energy band charge density distribution, a type II heterojunction was formed between h-BN and g-C3N4, and the migration direction of photogenerated charge was also consistent with this result. By calculating the three-dimensional differential charge density, it was verified that there was a built-in electric field at the interface between h-BN and g-C3N4. Electric field provided driving force for charge transfer. Based on the above positive factors, the photocatalytic performance of the composites was greatly improved, and the k value (0.0703 min−1) of photocatalytic degradation of TC was 33 times higher than that of bulk g-C3N4. This work provides a new strategy for the improvement of photocatalytic effects and broadens the applications of photocatalysts.
Display omitted
•Mo2C/TCN direct Z-Scheme heterostructure photocatalysts were synthesized.•The improvement in the activity is ascribed to the synergistic effects of Mo2C and TCN.•2 wt% Mo2C/TCN ...exhibits high photocatalytic activity and is stable in real water.•Effective charge transfer and separation was realized across the Z-Scheme system.•Mo2C acts as an electron trap and plays an important role in the charge transfer.
The pharmaceutical products have becoming ubiquitous in aquatic environment. Photocatalytic degradation is considered as a promising strategy to address this environmental threat. Here we showed new Mo2C/hollow tubular g-C3N4 hybrids (Mo2C/TCN) consisting of well-designed direct Z-scheme heterojunction with favorable charge transfer channels for efficient contaminants degradation. Compare to the traditional Mo2C/g-C3N4 type-I heterojunction reported in the previous literature, the powerful direct Z-scheme heterojunction retains the original redox ability of the component without changing its oxidation and reduction potential. By virtue of the hollow tubular architecture, more incident electrons are expected to be rapid trapped by Mo2C nanoparticles, which contributes to the effective separation of photoinduced hole-electron pairs. As a result, the optimized Z-scheme system exhibits impressive visible-light photocatalytic performance. Especially, the 2 wt% Mo2C/TCN photocatalysts exhibits superior photocatalytic performance for tetracycline degradation with a reaction rate of 0.0391 min−1, which is 3-times and 9-times higher than those of TCN and pristine g-C3N4, respectively. The outstanding performance strongly depends on the synergistic effects among the favorable electrical conductivity of Mo2C and the multitude of charge transfer channels provided by the Z-scheme heterojunction. This work provides a new idea of designing direct Z-scheme material and it sheds novel insight to establish photocatalytic model for environmental amendment.
As a member of Ubiquitin-specific protease subfamily, ubiquitin specific protease 7 (USP7) has been reported to participate in a variety of cellular processes, including cell cycle, apoptosis, DNA ...damage response, and epigenetic modification. However, its function in preimplantation embryos is still obscure. To investigate the functions of USP7 during preimplantation embryo development, we used siRNA to degrade endogenous USP7 messenger RNA. We found that USP7 knockdown significantly decreased the development rate of mouse early embryos. Moreover, depletion of USP7 induced the accumulation of the DNA lesions and apoptotic blastomeres in early embryos. In addition, USP7 knockdown caused an abnormal H3K27me3 modification in 2-cell embryos. Overall, our results indicate that USP7 maintains genome stability perhaps via regulating H3K27me3 and DNA damage, consequently controlling the embryo quality.
•Depletion of USP7 compromises the early embryo development.•USP7 knockdown increases DNA damage and apoptosis in mouse early embryos.•USP7 knockdown causes an abnormal H3K27me3 modification in mouse early embryos.
Li-O
batteries (LOB) are considered as one of the most promising energy storage devices using renewable electricity to power electric vehicles because of its exceptionally high energy density. Carbon ...materials have been widely employed in LOB for its light weight and facile availability. In particular, graphene is a suitable candidate due to its unique two-dimensional structure, high conductivities, large specific surface areas, and good stability at high charge potential. However, the intrinsic catalytic activity of graphene is insufficient for the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in LOB. Therefore, various surface functionalization schemes for graphene have been developed to tailor the surface chemistry of graphene. In this review, the properties and performances of functionalized graphene cathodes are discussed from theoretical and experimental aspects, including heteroatomic doping, oxygen functional group modifications, and catalyst decoration. Heteroatomic doping breaks electric neutrality of sp
carbon of graphene, which forms electron-deficient or electron-rich sites. Oxygen functional groups mainly create defective edges on graphene oxides with C-O, C=O, and -COO-. Catalyst decoration is widely attempted by various transition and precious metal and metal oxides. These induced reactive sites usually improve the ORR and/or OER in LOB by manipulating the adsorption energies of O
, LiO
, Li
O
, and promoting electron transportation of cathode. In addition, functionalized graphene is used in anode and separators to prevent shuttle effect of redox mediators and suppress growth of Li dendrite.
Reducing opportunism is a critical task to support channel performance and channel member satisfaction. Recent research into marketing channels focuses on the role of relational governance in curbing ...opportunism; this study advances this thesis by positing that relational governance encompasses both relational norms and collaborative activities (i.e., joint planning and joint problem solving). In turn, the current research investigates how these two aspects of relational governance independently and jointly check opportunism in marketing channels. The tests of the hypotheses involve 149 Chinese manufacturer–distributor relationships. The results show that relational norms have a negative effect on opportunism, but the effect of collaborative activities is contingent on the level of consistency between the relational norms and collaborative activities that mark the relationship. A low level of relational norms prompts joint planning to inhibit opportunism and joint problem solving to exacerbate it. However, a high level of relational norms reverses these effects: Joint planning fosters opportunism, and joint problem solving curbs it. Thus collaborative activities have different properties that need to be devised in accordance with relational norms if the goal is to reduce opportunism.
•Relational governance encompasses both relational norms and collaborative activities.•We investigate the direct and contingency effects of relational norms and collaborative activities on opportunism.•Relational norms have a negative effect on opportunism.•The effect of collaborative activities on opportunism depends on their level of consistency with relational norms.
•The evolution of PM in the process of NTP regeneration DPF was evaluated from the perspective of space-time.•The morphology evolution of pore deposition particles during NTP regeneration of DPF was ...revealed.•TG characteristic curve of EC shifted to lower temperature with promoting DPF regeneration.•The essence of NTP oxidative decomposition of PM is the process of removing carbon atoms.
In this paper, diesel particulate filters (DPFs) were regenerated at a low temperature (100 °C) using a non-thermal plasma (NTP) injection system. The physical and chemical characteristics of the particles deposited at different regeneration stages, such as their macromorphology, microstructure, oxidation activity, surface functional groups, and soluble organic fraction, were analyzed. The results showed that when NTP flowed through the DPF, the deposited particles were oxidized, decomposed, and then removed from the channels. The soot cake dispersed into blocks from an initially dense morphology and gradually shrank until it disappeared. The residual ash lost the initial spherical structure of the carbonaceous particulate matter (PM). The weak part of the flocculant structure of PM broke first during the oxidation of NTP active substances and decomposed into a chain structure. As DPF regeneration proceeded, O atoms were continuously bonded into the PM to form oxidation intermediate products that contained C-O, C=O, and other functional groups, which improved the PM oxidation activity. Changes in the physical and chemical properties of PM at the DPF regeneration interface were more significant than those at the most downstream sampling position. The high carbon atom fraction in the soluble organic fraction (SOF) decreased, and the DPF regeneration by NTP involved the continuous removal of carbon atoms.
Breast cancer is the most common cancer and the leading cause of cancer mortality in women worldwide. Hypoxia is an important factor involved in the progression of solid tumors and has been ...associated with various indicators of tumor metabolism, angiogenesis and metastasis. But little is known about the contribution of Hypoxia-Inducible Factor-2a (HIF-2a) to the drug resistance and the clinicopathological characteristics in breast cancer.
Immunohistochemistry was employed on the tissue microarray paraffin sections of surgically removed samples from 196 invasive breast cancer patients with clinicopathological data. The correlations between the expression of HIF-2a and ABCG2 as well as other patients' clinicopathological data were investigated.
The results showed that HIF-2a was expressed in different intensities and distributions in the tumor cells of the breast invasive ductal carcinoma. A positive staining for HIF-2a was defined as a brown staining observed mainly in the nucleus. A statistically significant correlation was demonstrated between HIF-2a expression and ABCG2 expression (p = 0.001), histology-grade (p = 0.029), and Ki67 (p = 0. 043) respectively.
HIF-2a was correlated with ABCG2 expression, histology-grade and Ki67 expression in breast invasive ductal carcinoma. HIF-2a could regulate ABCG2 in breast cancer cells, and could be a novel potential bio-marker to predict chemotherapy effectiveness. The hypoxia/HIF-2a/ABCG2 pathway could be a new mechanism of breast cancer multidrug-resistance.
http://www.diagnosticpathology.diagnomx.eu/vs/2965948166714795.
To evaluate the therapeutic effect of preoperative transcatheter arterial chemoembolization (TACE) combined with short-term systematic chemotherapy in the treatment of advanced Wilms tumor.
This was ...a retrospective study on 66 patients with unilateral advanced Wilms tumor, age 5 months to 11 years (median, 2.9 years; 30 boys and 36 girls), treated at our institution between 1995 and 2007. Characteristics of the patient population were maximal tumor diameter > 10 cm, or involvement of periaortic lymph nodes, or inferior vena cava invasion, or distal metastasis, or tumor with anaplastic histology. Patients were divided into three groups. Twenty patients were treated with conventional preoperative chemotherapy (PC group) using vindesine, actinomycin D, and pirarubicin for 4 weeks; 21 patients were treated in the TACE group with preoperative renal arterial chemoembolization using Lipiodol-pirarubicin-vindesine emulsion; and 25 patients were treated with preoperative chemoembolization combined with short-term systematic chemotherapy (T+S) for 2 weeks.
No drug-induced cardiotoxicity, nephrotoxicity, or hepatic dysfunction was observed. Complete surgical removal of the tumor was achieved in 12 (65.0%), 17 (80.9%), and 22 (88.0%) patients in the PC, TACE, and T+S groups, respectively (T+S group vs PC group, P = .030). The 2-year relapse-free survival rates were 65.0%, 80.9%, and 100.0% in the PC, TACE, and T+S groups, respectively (T+S vs PC, P = .001).
From our experience, preoperative chemoembolization combined with short-term systematic chemotherapy is able to achieve higher rates of complete tumor resection and relapse-free survival in the treatment of advanced Wilms tumor.
...missed diagnostic opportunities still exist worldwide, not only for patients presenting with high-risk cancer symptoms, but also for many patients at lower risk of cancer.1,2 Primary care ...physicians, including general practitioners in the UK, urgently need more refined guidelines and risk stratification approaches to manage patients with a range of cancer risks. Furthermore, one in six patients in primary care presents with symptoms that are persistent and last for over a year.3 These patients often have more tests and referrals, generating increased health-care costs and demands.4 However, guidelines on lower-risk and persistent symptoms are either non-existent or ambiguous, often reflecting the paucity of robust primary evidence on which to base recommendations. ...optimising risk stratification in patients who present with lower-risk symptoms, but who might have an intermediate risk of cancer, could have substantial positive effects on patient experiences. Having a previous urgent suspected cancer referral could influence patients’ future help-seeking behaviour by making symptom attribution complex and providing over-reassurance, therefore delaying help-seeking for subsequent possible cancer symptoms.8 Scott and colleagues highlight the need to develop and evaluate interventions that encourage timely help-seeking after previous investigations.9 Other potential interventions targeting patients at intermediate risk of cancer include more refined risk-stratification tools and electronic alerts within clinical information technology systems; electronic alerts can assist with active monitoring, providing safety-netting advice and reminding clinicians when further investigations or referrals are due.10 As increasing emphasis is placed on shared decision making between patients and clinicians, better knowledge of cancer risks in all patient groups might reduce diagnostic uncertainty and improve testing strategies.
PDF
