Carbon Dots: A Review with Focus on Sustainability.

Carbon dots (CDs) are an emerging class of nanomaterials with attractive optical properties, which promise to enable a variety of applications. An important and timely question is whether CDs can become a functional and sustainable alternative to incumbent optical nanomaterials, notably inorganic quantum dots. Herein, the current CD literature is comprehensively reviewed as regards to their synthesis and function, with a focus on sustainability aspects. The study quantifies why it is attractive that CDs can be synthesized with biomass as the sole starting material and be free from toxic and precious metals and critical raw materials. It further describes and analyzes employed pretreatment, chemical-conversion, purification, and processing procedures, and highlights current issues with the usage of solvents, the energy and material efficiency, and the safety and waste management. It is specially shown that many reported synthesis and processing methods are concerningly wasteful with the utilization of non-sustainable solvents and energy. It is finally recommended that future studies should explicitly consider and discuss the environmental influence of the selected starting material, solvents, and generated byproducts, and that quantitative information on the required amounts of solvents, consumables, and energy should be provided to enable an evaluation of the presented methods in an upscaled sustainability context.

An oncogenic role of lncRNA SNHG1 promotes ATG7 expression and autophagy involving tumor progression and sunitinib resistance of Renal Cell Carcinoma.

Renal cell carcinoma (RCC) is a malignant tumor with high incidence in adult kidney. Long non-coding RNAs (lncRNAs) have recently been recognized as important regulators in the development of RCC. However, whether lncRNA SNHG1 is associated with RCC progression remains to be elucidated. Here, the role of SNHG1 in RCC autophagy and sunitinib resistance was evaluated. Expression of SNHG1 in RCC tissues and cells was assessed using RT-qPCR. Western blot was utilized to measure the levels of autophagy-related molecules and ATG7. RNA pull-down and RIP assays were performed to confirm the molecular axis between SNHG1/PTBP1/ATG7. Cell proliferation, migration, invasion and apoptosis were analyzed by CCK-8, EdU, transwell and flow cytometry, respectively. The subcellular localization of SNHG1 was determined by an intracellular fractionation assay. The fluorescence intensity of GFP-LC3 autophagosome in RCC cells was detected. IHC staining was performed to test ATG7 expression in tumor tissues from nude mice. Here, a positive correlation of upregulated SNHG1 with poor prognosis of RCC patients was observed in RCC tissues and cells. SNHG1 knockdown suppressed tumor growth and reversed sunitinib resistance and autophagy of RCC cells. Additionally, SNHG1 was found to directly bind to PTBP1, thereby positively regulating ATG7 expression. Furthermore, we verified that SNHG1 mediated the malignant behavior of RCC cells through the PTBP1/ATG7 axis. To sum up, SNHG1 regulates RCC cell autophagy and sunitinib resistance through the PTBP1/ATG7 axis, which highlights a promising therapeutic target for RCC treatment.

An Admittance Control Method Based on Parameters Fuzzification for Humanoid Steering Wheel Manipulation.

Developing a human bionic manipulator to achieve certain humanoid behavioral skills is a rising problem. Enabling robots to operate the steering wheel to drive the vehicle is a challenging task. To address the problem, this work designs a novel 7-DOF (degree of freedom) humanoid manipulator based on the arm structure of human bionics. The 3-2-2 structural arrangement of the motors and the structural modifications at the wrist allow the manipulator to act more similar to a man. Meanwhile, to manipulate the steering wheel stably and compliantly, an admittance control approach is firstly applied for this case. Considering that the system parameters vary in configuration, we further introduce parameter fuzzification for admittance control. Designed simulations were carried out in Coppeliasim to verify the proposed control approach. As the result shows, the improved method could realize compliant force control under extreme configurations. It demonstrates that the humanoid manipulator can twist the steering wheel stably even in extreme configurations. It is the first exploration to operate a steering wheel similar to a human with a manipulator by using admittance control.

Cancer-Associated Fibroblasts Boost Tumorigenesis of Clear Cell Renal Cell Carcinoma via Exosome-Mediated Paracrine SNHG1.

Despite the dominant roles of cancer-associated fibroblasts (CAFs) have attached much attention in tumorigenesis, the CAFs-derived molecular determinants that regulate renal cell carcinoma (RCC) development remains elusive. Our previous study uncovered an oncogenic SNHG1 in the immune escape of RCC, whereas CAFs-derived exosomes could be a source accounting for increasing SNHG1 in RCC cells, this is still a mystery. The obtained CAFs and normal fibroblast (NFs) from fresh RCC and adjacent tissues were firstly identified using western blot and immunofluorescent staining. The enrichment of SNHG1 was validated by RT-qPCR. CAFs-derived exosomes were isolated from conditioned medium using ultracentrifugation method and ExoQuick-TC system. The internalization of exosomes, transfer of SNHG1, was measured by immunofluorescence. Regulation of conditioned medium or exosomal SNHG1 from CAFs on RCC biological functions was evaluated by CCK-8, EdU incorporation, colony formation, and transwell assays to assess the RCC cell proliferation, migration, and invasion. SNHG1 was significantly upregulated in CAFs isolated from RCC stroma. Exosomes derived from CAFs transferred SNHG1 to RCC cells and resulted in an increased SNHG1 expression in RCC cells. The exosomes excreted by CAFs promoted RCC cell proliferation, migration, and invasion, whereas the promotion effect of CAFs-exosomes on RCC progression was attenuated by SNHG1 knockdown. The present study revealed a new mechanism of exosomal SNHG1 extracted from CAFs enhanced RCC progression and may provide a potential target for the treatment of RCC.

Defects and Structural Limitation-Induced Carbon Dots-Silica Hybrid Materials with Ultralong Room Temperature Phosphorescence.

Carbon dots-based room temperature phosphorescent (RTP) materials have attracted widespread attention owing to their excellent optical properties. However, there still is a challenge to fabricate carbon dots-based materials simultaneously showing long RTP lifetime and high phosphorescent quantum yield. Herein, we have designed a kind of carbon dots-silica hybrid material that can produce RTP emission with ultralong lifetime and also high phosphorescent quantum yield (1.3 s and 11.22%). Both chemical and optical analytical characterizations indicate the source of the outstanding RTP performance as the synergistic strategy of abundant electron traps, highly rigid network, and stable covalent bond. The findings provide a new design idea to achieve novel carbon dots-based RTP materials, showing broad application prospects in optical anticounterfeiting, optoelectronics, and others.

Rational Regulation of Crystalline/Amorphous Microprisms-Nanochannels Based on Molecular Sieve (VSB-5) for Electrochemical Overall Water Splitting.

Rational regulation of the composition and structure of electrocatalysts is crucial to the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, a new electrocatalyst of nickel phosphate microprism (VSB/NiPO) is developed via a simple solvothermal reaction. The microprism is mainly composed of Versailles-Santa Barbara-5 (VSB-5, molecular sieve) with unique nanochannels, which contribute to accelerating mass transfer and exposing more active sites, thus displaying excellent HER activity. Subsequently, the crystallinity and electronic structure of the framework are modulated by incorporating Fe with the combination of calcination and impregnation. The nanochannels are converted to the amorphous arrangement, and the Ni centers are regulated to the higher valence. The resultant Fe-VSB/NiPO-500 exhibits a low OER overpotential of 227 mV at 50 mA cm-2 . Interestingly, an integrated electrolyzer assembled by VSB/NiPO(-) and Fe-VSB/NiPO-500(+) performs well for overall water splitting, which requires only 1.487 V to achieve 10 mA cm-2 , and remains stable at 100 mA cm-2 over 100 h. This finding opens a new avenue for developing VSB-5 in the field of electrocatalysis.

Improving the Photocatalytic Activity of Mesoporous Titania Films through the Formation of WS2/TiO2 Nano-Heterostructures.

Heterostructures formed by anatase nanotitania and bidimensional semiconducting materials are expected to become the next-generation photocatalytic materials with an extended operating range and higher performances. The capability of fabricating optically transparent photocatalytic thin films is also a highly demanded technological issue, and increasing the performances of such devices would significantly impact several applications, from self-cleaning surfaces to photovoltaic systems. To improve the performances of such devices, WS2/TiO2 heterostructures obtained by incorporating two-dimensional transition metal dichalcogenides layers into titania mesoporous ordered thin films have been fabricated. The self-assembly process has been carefully controlled to avoid disruption of the order during film fabrication. WS2 nanosheets of different sizes have been exfoliated by sonication and incorporated in the mesoporous films via one-pot processing. The WS2 nanosheets result as well-dispersed within the titania anatase mesoporous film that retains a mesoporous ordered structure. An enhanced photocatalytic response due to an interparticle electron transfer effect has been observed. The structural characterization of the heterostructure has revealed a tight interplay between the matrix and nanosheets rather than a simple additive co-catalyst effect.

Dispersion-assisted tunable fluorescence from carbon dots.

In this study, carbon dots (CDs) synthesized by hydrothermal method with amino-rich surface exhibit tunable fluorescence across entire visible range by simply controlling the concentration. A comprehensive comparison has been performed for the first time between concentration-induced aggregation of the single-type CDs and electrostatic-induced agglomeration of opposite-charged CDs in terms of their fluorescence properties. Experimental results show that both the aggregation of CDs and internal absorption filtration are possible causes of the concentration-dependent fluorescence emission. Subsequently, the inter distance of adjacent CDs in their aggregates was enlarged by forming rigid double-stranded DNA (dsDNA) between adjacent CDs through base pairing. It is clear that the contact of CDs induces the changes of fluorescence emission and light absorption. Through a better understanding of the mechanisms behind concentration-induced multicolor emission, this work can provide a novel strategy to develop the advanced applications of CDs.

Tumor burden score dictates prognosis of patients with combined hepatocellular cholangiocarcinoma undergoing hepatectomy.

Background: The prognostic value of the tumor burden score (TBS) in patients with combined hepatocellular-cholangiocarcinoma (cHCC-CCA) remains unknown. This study aimed to investigate the impact of TBS on long-term outcomes after surgery. Methods: Patients who underwent radical-intent resection between June 2013 and December 2019 were retrospectively reviewed. Kaplan-Meier curves were used to analyze patient survival, and disease-free survival (DFS) and overall survival (OS) were examined in relation to TBS. Results: A total of 178 patients were included in this study, with 119 in the training cohort and 59 in the validation cohort. Kaplan-Meier curves showed that TBS was a strong prognostic indicator in patients with cHCC-CCA. Elevated TBS was associated with poorer DFS and OS (both P-value < 0.001) and was identified as an independent prognostic indicator. In addition, the prognostic value of TBS outperformed tumor size and number alone, microvascular invasion, and lymph node invasion. The prognostic significance of TBS was confirmed by the internal validation cohort. Conclusions: The present study suggested the significance of tumor morphology in assessing the prognosis of patients with cHCC-CCA who undergoing curative resection. The TBS is a promising prognostic index in patients with cHCC-CCA. Elevated TBS was related to a lower long-term survival rate and was identified as an independent risk factor for poor DFS and OS. Further research is needed to verify our results.

Silane-Functionalized Carbon Dots and Their Polymerized Hybrids: From Optoelectronics to Biotherapy.

Nanomaterials usually manifest unique properties in solutions but will be undermined in the solid state. It is necessary to incorporate them into substrates or hybrid them with other functional materials for multiple devices and applications. Though there are a variety of methods to inherit their intrinsic properties like fluorescent and mechanical performance, most nanohybrid materials would lose their transparency irreversibly when construct solid-state devices. As a hot topic of nanomaterials in recent years, scientific works found a type of carbon dots using silane coupling agents as precursors that can overcome the shortcoming. These carbon dots, called silane-functionalized carbon dots (SiCDs), are catching increasing interest due to their versatility. Silane coupling agents endow SiCDs with the ability to disperse in solvents or polymerize with matrices by blending or covalent bonds without loss of transparency and decline of performance. The distinguishing features make SiCDs an ideal high transmittance, high doping concentration nanomaterial. The synergistic effect of SiCDs and hybridized sol-gel solid structures can not only hold the optical features of CDs but also enhance their original physical and chemical performance. This highlight focuses on the connection between SiCDs and organosilanes. Plus, preparation methods, applications, and prospective of SiCDs are mentioned.