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Developing hollow-structure quantum dot carriers to increase quantum luminous efficiency is a creative idea for designing a novel sensor. A ratiometric hollow CdTe@H-ZIF-8/CDs@MIPs sensor was developed for the sensitive and selective detection of dopamine (DA). CdTe QDs and CDs were used as the reference signal and recognition signal, respectively, and thus showed a visual effect. MIPs provided high selectivity toward DA. The TEM image demonstrated that the sensor was a hollow structure, which could have ample opportunity to excite quantum dots to emit light through multiple light scattering through holes. In the presence of DA, the fluorescence intensity of the optimum CdTe@H-ZIF-8/CDs@MIPs was remarkably quenched by DA, achieving a linear range of 0–600 nM and a limit of detection of 12.35 nM. The developed ratiometric fluorescence sensor showed an obvious and meaningful color change with a gradual increase in DA concentration under a UV lamp. Moreover, the optimum CdTe@H-ZIF-8/CDs@MIPs was remarkably sensitive and selective in detecting DA among various analogs and showed good anti-interference ability. The HPLC method also further confirmed that CdTe@H-ZIF-8/CDs@MIPs shows good practical application prospects. [ABSTRACT FROM AUTHOR]

Developing a novel and highly efficient catalytic oxidation system for environmental protection was an important task. In this work, inspired by the photocatalytic system and peroxydisulfate (PDS) system, the magnetic γ‐Fe2O3/h‐BN composite was designed for synergetic catalytic. The tetracycline was selected to study the degradation activity of all‐obtained samples. Among, the sample with a weight ratio of 7 % has the optimum catalytic performance. The enhanced catalytic performance was attributed to the separation of electron‐hole pairs and contact with pollutant of γ‐Fe2O3/h‐BN composite. Under visible‐light illumination, the γ‐Fe2O3/h‐BN composite could generate superoxide free radicals (O2.−)) and holes (h+) to decompose pollutant, while the addition of PDS, the PDS would excite to generate hydroxyl radicals (⋅OH) and sulfate radicals (SO4.−) for further degrading pollutant. Under optimal condition, the degradation rate reached 90 % within 90 min. In addition, the investigation of tetracycline (TC) degradation under different experimental conditions (pH, catalyst dosage, PDS concentration, various salt) was conducted. This study provided a novel synergetic catalytic system for wastewater treatment. [ABSTRACT FROM AUTHOR]

The modification of photocatalyst was the vital task for improving photocatalytic performance. Inspired by multi-level effect and activation regions of N atom, multi-level bismuth-based spheres (Bi2Ti2O7) and N-doped graphene quantum dots (N-GQD) were constructed for the photocatalytic application. Experiments demonstrated that the N-GQD/Bi2Ti2O7 multi-level spheres showed higher photocatalytic performance due to the multi-level effect and activation regions. Meanwhile, a series of characterizations proved that the separation efficiency of electron–hole pairs was improved after the N-GQD modifications. A possible mechanism was proposed for investigating N-GQD/Bi2Ti2O7 materials in the photocatalytic field. A novel N-GQD modified multi-level Bi2Ti2O7 spheres exhibited higher photocatalytic activity due to efficient electron transfer via N atoms. [ABSTRACT FROM AUTHOR]

Black TiO2 and metal–organic frameworks (MOF) are great materials with light-harvesting ability, redox power and consequently catalytic activity. Here, the integration of MIL-100(Fe) with TiO2(B) composite was designed for photocatalytic application, which greatly promoted light-harvesting and charge transfer. As expected, the integrated TiO2(B)/MIL-100(Fe) composite showed high photocatalytic activity due to unique Fe–O–Ti bonds that were constructed, which acted as an electronic tunnel to reduce electronic transfer resistance between MIL-100(Fe) and TiO2(B). In addition, the presence of Fe–O clusters in MIL-100(Fe) can also promote the charge dissociation and improve catalytic activity via the Fe3+/Fe2+ redox cycle. This achievement would help us to understand and design charge transfer pathways in the integration of MOF/semiconductor photocatalysts. [ABSTRACT FROM AUTHOR]

Spectrum efficiency is a critical performance metric in wireless communications due to an increasing demand for radio spectrum to support high data rate applications. Direct sequence spread spectrum technology enables a code division multiple access (CDMA) system a strong anti-interference capability but with a relatively low spectrum efficiency. To address this issue, complementary coded scrambling multiple access (CCSMA) (X. Liu et al., in 2018) was proposed to use three-dimensional (space-time-frequency) resources for performance enhancement. However, in a CCSMA system, if the number of multipath returns is larger than the number of transmit (Tx) antennas, a code reuse problem occurs to degrade bit error rate performance significantly. This work designs a new scrambling code, namely generalized complementary coded scrambling multiple access (GCCSMA) codes, to overcome the code reuse problem in CCSMA. GCCSMA uses complementary codes, scrambling modulation, and multiple-input-multiple-output (MIMO) techniques jointly, which works well even in multipath channels with more paths than the number of Tx antennas. The analysis and simulations are conducted to validate the effectiveness of the proposed GCCSMA system. [ABSTRACT FROM AUTHOR]

The fluorescence detection of environmental pollution residues is hugely significant; thus, the improvements in sensitivity and selectivity are still a great task. In this work, a novel molecularly imprinted fluorescence sensor (CDs&ZIF-8@MIPs) with a core–shell structure was prepared for the highly sensitive and selective quantification of malachite green (MG). The high sensitivity was contributed from carbon dots (CDs) as the fluorescence materials and ZIF-8 nanoparticles served as the support materials to ameliorate the dispersibility of CDs. The high selectivity is mainly derived from fabricating thin molecular imprinting polymers in ZIF-8 surfaces. Under the optimum conditions, CDs&ZIF-8@MIPs displayed rapid reaction time (2.0 min), lower detection limit (2.93 nM) with the concentration linear range of 20–180 nM and high selectivity to MG among MG analogs. Importantly, the developed monitoring method was successfully applied to MG determination with the satisfactory recoveries in environmental water samples. This present work effectively improved the sensitivity and selectivity of fluorescence sensors for MG detection. [ABSTRACT FROM AUTHOR]

In a frequency division complementary coded CDMA (FD-CC-CDMA) system, multiple tuners have to be used for multi-carrier modulation, which has a very high complexity and power consumption. In this paper, we propose a CP-free OFDM scheme to implement multi-carrier modulation in an FD-CC-CDMA system, which is named as CP-free OFDM-CC-CDMA system. The transmitter in the CP-free OFDM-CC-CDMA system offers a unique flexibility to adjust the amount of data processed at the same time to ensure that the OFDM block size exceeds the delay spread of a multipath channel, which attributes to effective mitigation of multipath induced inter-symbol interference (ISI). At the receiver of a CP-free OFDM-CC-CDMA system, minimum mean square error (MMSE) equalization and MMSE combining are used to mitigate multi-user interference (MUI) and inter-carrier interference (ICI). The obtained results show that a CP-free OFDM-CC-CDMA system offers a much higher transmission efficiency than FD-CC-CDMA and OFDM-DS-CDMA systems. In addition, the proposed CP-free OFDM-CC-CDMA system outperforms OFDM-DS-CDMA system in terms of bit error rate due to its inherent powerful diversity gain. [ABSTRACT FROM AUTHOR]

A traditional direct sequence CDMA (DS-CDMA) system works based on spreading codes, which should have good auto-correlation and cross-correlation properties to eliminate multiple access interference (MAI) and multipath interference (MI). However, to find a large number of good spreading codes is extremely difficult, and thus the capacity of a DS-CDMA system is limited strictly by the number of available spreading codes. This work proposes a downlink DS-CDMA design to enable multiple access using only one spreading code, namely identical code cyclic shift (ICCS) code, where in-phase and quadrature channels are used to transmit data and pilot, respectively. In particular, the ICCS code is used at a transmitter to perform DS modulation for user data, which is then sent to the in-phase channel. At the same time, the pilots are sent over the quadrature channel in a time-division multiplex (TDM) mode to construct a correlation matrix of ICCS code. At a receiver, MAI is removed by so-designed pilots plus a matched filter-bank. Simulation results show that the proposed ICCS multiple access (ICCSMA) can achieve a better performance than a traditional DS-CDMA system in a high signal to noise ratio region. ICCSMA serves as a bridge to turn CDMA to NOMA to enable massive connectivity in 5 G and beyond communications. [ABSTRACT FROM AUTHOR]

To completely utilize the high redox ability of photo-induced charge carriers. Here, a Z-scheme photocatalyst of TiO 2 QDs/Bi 12 TiO 20 (TBT) composites with TiO 2 QDs fragment attached to the surface of Bi 12 TiO 20 (BTO) was prepared and the photocatalytic activity was evaluated by degradation of gatifloxacin (GF). The optimal photocatalytic performance of TBT displayed 3 times higher than bare BTO. The improved photocatalytic performance was ascribed to the effective separation of the charge carriers between TiO 2 QDs and BTO via the direct Z-scheme heterojunction. Such a strategy for the construction of Z-scheme TBT composites for removal of organic pollutants, proving new insights into design photocatalyst. • A TiO 2 quantum dots fragment was prepared and covered on the surface of Bi 12 TiO 20. • A Z-scheme heterojunction was formed between TiO 2 QDs and Bi 12 TiO 20. • The TOQs played as the sensitizer to increase the photocatalytic activity. [ABSTRACT FROM AUTHOR]

In this work, a biofiber was used as the natural polymer carrier to design a BiVO 4 QDs/cellulose fiber composite for photocatalytic application. The biofiber was obtained from bamboo, which was green, abundant and short growth cycle in Asia. Naturally rich groups of biofiber provided many sites to absorb the Bi3+ to form the uniform distribution for BiVO 4 QDs. Moreover, a series of results indicated the strong connection was formed between biofiber and BiVO 4 QDs, which could increase the stability and electron transfer. Therefore, the new composite photocatalyst exhibited better stability and effectively photocatalytic activity. Moreover, the possible mechanism of synthesis and photocatalytic were discussed, which provided insight for synthesizing photocatalytic based on biomaterials. Extracting cellulose fiber of bamboo to designed a novel BiVO 4 QDs/fibers composite photocatalyst via the in-situ method, which showed an enhanced stability and photocatalytic activity. Image 1 • Bamboo as the source to prepared cellulose fibers due to its abundant and short growth cycle. • A novel BiVO 4 QDs/fibers composite photocatalyst was obtained via the in-situ method. • Rich groups of natural cellulose fibers provided many sites to form the stability and distribution BiVO 4. • The mechanism of synthesis and the photocatalytic process were discussed and proposed. [ABSTRACT FROM AUTHOR]

Highlights • The CDs were firstly fabricated using osmanthus fragrans leaves as carbon source by hydrothermal treatment methods. • A molecular imprinting ratiometric fluorescence sensor for detection of ciprofloxacin has been synthesized. • The MIPs@CdTe/CDs@SiO2 sensor was displayed ultrasensitive and excellent selective determination tociprofloxacin. • A novel photocatalyst of TiO2/CDs/CdTe QDs was fabricated for the degradation of ciprofloxacin. Abstract The sensitive monitoring and rapid removal antibiotics residues are great challenges and hugely significant for the environmental protection. In this work, a green and facile strategy was obtained for the fabrication of highly fluorescent carbon dots (CDs) through hydrothermal treatment of osmanthus fragrans leaves as carbon source and polyethyleneimine as nitrogen source. Then the prepared blue CDs were combined with red CdTe quantum dots (QDs) for constructing MIPs@CdTe/CDs@SiO 2 was applied to selectively and sensitively assay ciprofloxacin (CIP) and TiO 2 /CDs/CdTe QDs as photocatalyst for the degradation of CIP. Under optimum conditions, MIPs@CdTe/CDs@SiO 2 has exhibited lower detection limit of 0.0127 nM with the linear range of 0–60 nM, and successfully applied to monitor CIP in human urine samples. Moreover, the TiO 2 /CDs/CdTe QDs also displayed good photocatalytic degradation of activity to CIP under sunlight irradiation. This present work which was rational constructed materials based on CDs and CdTe QDs illustrates the great practicability and potential to rapid and efficient determination and removal environmental pollutants in the future. [ABSTRACT FROM AUTHOR]

Abstract In this work, two Bi-based semiconductors composites was synthesized through the BiVO 4 quantum dots (BVO QDs) was grown on the Bi 12 TiO 20 (BTO) via an in-suit growth with the ultrasonic method, which was more stability and evenly dispersed. As expected, the BVO-BTO composites exhibited increased visible-light-driven photocatalytic performance for photo-degradation due to the advantages of BVO QDs. Moreover, the possible mechanism of BVO-BTO composites was studied by trapping experiment, photocurrent, UV–vis and so on. The results demonstrated that the BVO QDs can widen the light response range to visible region and hasten the charge transfer and separation. Thus, the photocatalytic activity was enhanced through the BVO QDs decorated on BTO, which provided a new idea for designing Bi-based materials. Highlights • Two Bi-based materials were used to design the BiVO 4 quantum dots/Bi 12 TiO 20 composites. • The in-suit growth with the ultrasonic method was benefit to stability and dispersed. • The BVO-BTO composites have a better light response and electron transfer. [ABSTRACT FROM AUTHOR]

• Black Bi 4 Ti 3 O 12 nanosheet was synthesized. • Black Bi 4 Ti 3 O 12 have oxygen vacancy and disorder layer. • Black Bi 4 Ti 3 O 12 exhibited extend light absorption and high photocatalytic activity. In this work, a simple method to prepare defect two-dimension (2D) Bi 4 Ti 3 O 12 nanosheets material by NaBH 4 reduction with Argon atmosphere was reported. The results of EPR and XPS demonstrated that the presence of oxygen vacancy in Bi 4 Ti 3 O 12 , which resulted in color changed and extend photon-absorbance. By comparing to pristine Bi 4 Ti 3 O 12 , the black Bi 4 Ti 3 O 12 exhibited higher photocatalytic activity to pollutants. The mechanism was also proposed for exploring the defect in the photocatalytic process. [ABSTRACT FROM AUTHOR]

Abstract In this work, a simple method to load of g-C 3 N 4 quantum dots (CN QDs) onto Bi 2 Ti 2 O 7 (BTO) microsphere with the amount of CN QDs (3, 7, 10 and 15%). The photocatalyst was used for the treatment of water pollutants under visible-light illumination, which proved that CNBTO composites showed improved photocatalytic activity matched up to pure BTO. Reformation of BTO with CN QDs enhanced the light assimilation capacity, and promoted the isolation of photo-induced electron-hole pairs. The trapping experiments and ESR were announced the holes (h+) and superoxide oxide (O 2 −) played the key role, and the relative mechanism of the photocatalytic process was proposed. Meanwhile, the effects of CN QDs content, pH and initial pollutant concentration on the removal efficiency of ciprofloxacin (CIP) were studied. Results showed that the CN QDs loaded on BTO presented higher photocatalytic efficiency, and an optimum value for the dosage of photocatalytic in pH 8.0. Graphical Abstract The g-C 3 N 4 quantum dots modified Bi 2 Ti 2 O 7 microsphere for enhancing separation efficiency of electron-hole pairs. Unlabelled Image Highlights • The CN QDs have superior electron transfer ability and enriched light harvesting. • The CN QDs were coupled with Bi 2 Ti 2 O 7 microsphere have exhibited enhanced photocatalytic activity. • The CN QDs extends the light absorption of Bi 2 Ti 2 O 7 microsphere. [ABSTRACT FROM AUTHOR]

Abstract Many recent advances in constructing green metal-free materials have opened new possibilities in catalysis. To explore and enhance the photocatalytic performance of g-C 3 N 4 quantum dots (CN QDs), the metal-free materials of CN QDs embedded in the h-BN was successfully synthesized by calcination the mixture of melamine and h-BN. The studies proved the CNBN has appeared red-shift due to the quantum size effect and 2D h-BN. The CN QDs were embedded into the h-BN could not only facilitate the separation and transfer, but also the h-BN terminated with OH groups could act as active sites, thus enhanced the photocatalytic performance. Moreover, this work may pave the way for the application of CN QDs and fabricate 2D h-BN composites for green metal-free materials in another field. Graphical abstract A free-metal composites for environmental pollution treatment. Unlabelled Image Highlights • A metal-free materials were synthesized by the one-pot green procedure. • The composites were exhibited red-shift for increasing light absorption. • The efficiency of electrons separation and transfer enhanced the lifetime of active species. • The OH groups acted as active sites further improved the photocatalytic performance. [ABSTRACT FROM AUTHOR]

In this work, a novel, simple, economical and green carbon quantum dots (CQDs) were obtained by hydrothermal method using bamboo as a carbon source at the first time. In order to further the use of such CQDs, we reported the facile fabrication of CQDs/Bi 3 Ti 4 O 12 (BTO) nanosheets photocatalysts. The experimental results indicated that CQDs were successfully coupled with BTO nanosheets, exhibiting excellent photocatalytic activity than bare BTO. The improved photodegradation efficiency was attributed to the extended light absorption range, and increased separation rate of electron-holes pairs. At last, a possible photocatalytic mechanism was proposed. The design of such CQDs from the creature with semiconductor can be extended to photocatalytic systems. [ABSTRACT FROM AUTHOR]

Cyclic prefix (CP) is used in OFDM/OFDMA systems for data transmission over multipath channels at a dear price of spectral efficiency degradation. This work aims to design a CP-free OFDM/OFDMA system for futuristic high-speed communications, where data block length can be shorter than channel delay spread. In particular, we utilize a time domain precoding scheme working jointly with a multiblock decision feedback equalization algorithm to mitigate intersymbol interference and intercarrier interference caused by multipath propagation. The satisfactory performance of the scheme is validated by simulation results, showing that the proposed CP-free OFDM/OFDMA scheme with known channel state information at transmitter and receiver offers a significantly higher spectral efficiency than traditional CP-based OFDM/OFDMA schemes. [ABSTRACT FROM AUTHOR]

This work reports the direct transformation of the biomass of bamboo into carbon spheres by two step hydrothermal carbonization (HTC) at 180–200 °C. Such carbon spheres have potential applications as electrode materials with excellent electrical conductivity and high chemical stability. The biochar spheres (BS) were modified via protonation of g-C3N4 to form non-metallic photocatalysts with a unique core–shell architecture. In the BS@g-C3N4 core–shell photocatalysts, the protonated g-C3N4 sheets were the main photocatalyst and the biochar spheres acted both as a reservoir and a sensitizer, and displayed outstanding light absorption in nearly the entire wavelength range, due to the narrower gap of the sp2 carbon cluster and large amounts of carbon clusters. Conversion of raw biomass into stable carbon materials under relatively mild conditions offers a promising route to overcoming the challenges in obtaining biochar materials with precisely controlled morphology. Building a green non-metallic photocatalyst is an environmentally friendly embodiment of this. [ABSTRACT FROM AUTHOR]

A hollow fluorescence sensor of H-ZIF-8/CDs@MIPs was designed with biomass CDs and ZIF-8, which showed a better selectively and sensitivity towards BHb in real samples. [Display omitted] • The leaves were used for the preparation fluorescence carbon dots. • A hollow fluorescence sensor was designed for the detection of hemoglobin. • The unique fluorescence sensor has the potential for detecting hemoglobin in bovine urine. To develop non-toxic, highly efficient and selective fluorescence sensors was a significance research. In this work, a novel hollow fluorescence sensor was designed with biomass carbon dots (CDs), ZIF-8 and molecularly imprinted polymers (MIPs) via aqueous polymerization. The results demonstrated such unique structure fluorescence sensor exhibited fast response time, excellent stability and highly selectively towards bovine hemoglobin (BHb). Even in a complex environment, the hollow fluorescence sensor (H-ZIF-8/CDs@MIPs) still has a good recognition effect on BHb. Under an optimized condition, the hollow fluorescence sensor was quenched linearly with BHb concentration in the range of 0.058–4.5 μM with the detection limit of 15.6 nM. In addition, a possible quenching mechanism of hollow fluorescence towards BHb was confirmed resonance energy transfer (FRET). In the actual application process, the hollow fluorescence sensor showed a better detection performance towards BHb with the recoveries ranged of 98.6–101.1 %. This work provided a strategy to design green and unique hollow fluorescence sensor for practical application. [ABSTRACT FROM AUTHOR]

In this study, a conversion method and molecular imprinting technology were used to design molecularly imprinted polymers (MIP)-based ratiometric fluorescence test papers. The ZnO quantum dots (ZnO QDs) acted as the background quantum dots and ZIF-8 raw material. Carbon dots (CDs) were used as the identification signals. The imprinting layer achieved a selective function. Therefore, a ZnO@ZIF-8/CDs@MIPs sensor was designed for the detection of Bisphenol A (BPA). The sensor exhibited a fast response time for BPA detection. In addition, the sensor demonstrated that effective detection of BPA can still be achieved in complex environments. The detection limit of this sensor was 0.778 nM with a linear range of 0–60 nM. The corresponding test solutions exhibited clear changes from blue to yellow. The selectivity experiments results demonstrated that ZnO@ZIF-8/CDs@MIPs only exhibit excellent selective recognition effect for BPA. ZnO@ZIF-8/CDs@MIPs-2 was used for the detection of BPA in canned food and compared with the results of HPLC detection of BPA. The two spiked recovery ranges were 96.58–102.04% and 97.43–103.82%, respectively. In addition, the prepared ZnO@ZIF-8/CDs@MIPs-2 test paper visually recognized BPA under ultraviolet light. This study provides guidelines for the design and application of fluorescent test papers for quick detection in practical applications. A ZnO@ZIF-8/CDs@MIPs fluorescence sensor was constructed for selective and sensitive detecting bisphenol A (BPA) with naked-eye observation. [Display omitted] • ZnO@ZIF-8 core-shell nanodots were prepared by self-template method. • A novel ZnO@ZIF-8/CDs@MIPs-2 with visualization and selectivity was synthesized by precipitation polymerization. • Portable fluorescent test strips were designed for timely detection. • The actual sample detection results of the fluorescence sensor were consistent with HPLC method. [ABSTRACT FROM AUTHOR]

In this paper, a novel fluorescent nanoswitch based on carbon dots (CDs) was developed for the sensitive and selective determination of Hg and I. The CDs were obtained by simple hydrothermal process and had a strong fluorescence emission at 440nm. The fluorescence of the CDs can be selectively quenched by Hg ion, and then the I was added into the system, which can interact with Hg and recover fluorescence of the CDs. Under optimal conditions, the quenching fluorescence intensity on addition of Hg has obtained a satisfactory linear relationship covering the linear range of 0-50M with the linear relationship (), and the limit of detection is 0.047M. The additions of I could lead to the fluorescence intensity of the solution of CDs and Hg (50M) recover rapidly, which is linearly related () to the concentration of I in the range from 0 to 70M, the detection limit for I was calculated to be 0.084M. Moreover, the developed method to detect Hg and I was evaluated in real examples, and the fluorescence switching can sensitively and selectively detect Hg and I over some potentially interfering ions, the recoveries were up to 97.8-107.0% and 96.7-106.6%, respectively. A water-soluble fluorescent nanoswitch of carbon dots (CDs) has been designed for detecting Hg and I, which was fabricated by hydrothermal process. Hg ions can be recognized by the amino groups of the CDs to form charge-transfer state and result in quenching fluorescence of the CDs. After adding I ions to the system of CDs/ Hg, the Hg ions were extracted from the CDs due to the stronger binding between Hg and I, leading to the released CDs having restrained the photo-induced electron transfer and recovered the fluorescence. [ABSTRACT FROM AUTHOR]

The use of cyclic prefix (CP) allows all existing orthogonal frequency-division multiplexing or multiple access (OFDM/OFDMA) systems to realize high-data-rate transmission in frequency-selective fading channels at the expense of losses in spectrum efficiency, energy efficiency, and transmission rate (SET). This paper proposes a CP-free OFDM/OFDMA design. Unlike traditional OFDM/OFDMA systems, the proposed CP-free OFDM/OFDMA does not insert CPs between symbols at the transmitter side. The neighboring symbols in frequency-selective fading channels will be overlapped at a receiver, and decision feedback equalization (DFE) is performed before FFT operation for intersymbol interference (ISI) removal. After DFE, each symbol consists of multipath returns with different linear shifts (LSs), which may result in intercarrier interference (ICI). Therefore, the output symbols from the DFE will be sent to a CP restoration unit for LS-to-cyclic-shift (CS) conversion. We call this a CP-free OFDM/OFDMA system symbol CS equalizing OFDM/OFDMA (SCSE-OFDM/OFDMA), whose system design is introduced in detail in this paper. We will show that SCSE-OFDM/OFDMA offers a much higher SET than traditional OFDM/OFDMA systems in frequency-selective fading channels. [ABSTRACT FROM PUBLISHER]

Boosting the photocatalytic activity with the help of surface plasmon resonance (SPR) effect has been demonstrated as an effective approach. In this work, the metallic Bi was deposited on surface of Bi 12 TiO 20 (BTO) via in-situ growth. A series of characteristics was used to analyze the morphology, light properties, crystal structure, chemical position of Bi/BTO composite. The Bi/BTO composite showed increased light absorption and smaller electron transfer resistance. The metallic Bi not only has the SPR effect to generate hot electrons to promote the production of more active species, but also the formed Schottky junction can promote the separation of electrons. Thus, the Bi/BTO composite exhibited higher photocatalytic activity. In addition, the possible photocatalytic mechanism also proposed for deep developing the plasmonic photocatalyst. • One-stpe in-situ metallic Bi deposited Bi 12 TiO 20. • The electron could transfer through Schottky junction to achieve the separation electron-hole pairs. • SPR effect of metallic Bi resulted in the production of hot carriers [ABSTRACT FROM AUTHOR]

• One-step hydrothermal for the synthetization of BiVO 4 -C nanocomposite. • Lignin was controlled the self-assembly process of BiVO 4. • The lignin was carbonized to porous carbon materials. • BiVO 4 -C nanocomposite showed the enhanced photocatalytic activity. Explorations of biomass materials have emerged as a novel strategy to control the synthesis of semiconductor and improve the photocatalytic performance. Here, a lignin-derived porous structure of BiVO 4 -C nanocomposite was prepared via one-step hydrothermal approach. In the preparation process, lignin not only effectively controlled the growth of BiVO 4 but also carbonized to form a porous structure of biochar-based semiconductor photocatalyst. The studies demonstrated that the BiVO 4 -C nanocomposite have enhanced photocatalytic activity due to the departure of electron-hole pairs and charge migration. These insights provided useful insight for the design of efficient biomass-based photocatalyst for environmental protection and green energy. [ABSTRACT FROM AUTHOR]

Developing a green, non-toxic and easy to synthesize of fluorescence probe for fast and visual detecting trace water in various organic solvents was an important task. Here, a novel dual-emission fluorescence probe (b/r-CDs) was designed based on the red CDs (r-CDs) and blue CDs (b-CDs) to detect the trace water and enhance the visualization for naked-eye observation in different organic solvents. Among, the red fluorescence carbon dots (CDs) was found to have the capability to monitor trace amounts of water, which synthesized with green tea by facile ultrasonic method. Further, Such a dual-emission probe could fast monitor trace water in various organic solvents with high stability and fast response. Importantly, a synergistic mechanism of the dynamic process (b-CDs) and static quenching (r-CDs) was proved for the study of water detection. Moreover, the test paper was made for detecting trace water in different organic solvents, achieving convenient and effective detection. Image 1 • A red fluorescence CDs obtained from green tea and showed the potential for monitoring trace water in organic solvents. • The dual-emission fluorescence probe was designed with blue and red fluorescence CDs for detecting trace water.. • The synergistic mechanism of the dynamic process and static quenching for enhancing visualization effect. • The test strips made for quick and easy visual inspection of trace water. [ABSTRACT FROM AUTHOR]

In an orthogonal frequency division multiplexing (OFDM) system, cyclic prefix (CP) has to be added to eliminate multipath-induced inter-symbol interference (ISI) with a severely sacrificed bandwidth efficiency. Peak-to-average ratio (PAPR) may impair its performance further if a large number of carriers are used. On the other hand, traditional multi-carrier modulation suffers a prohibitive complexity, which can not be implemented with colorred current available silicon technologies. This work proposes a cost-effective way to implement multi-carrier modulation, namely multi-layer quadrature (MLQ) modulation, which requires only two oscillators. As an application example, we apply MLQ modulation to a complementary coded code division multiple access (MLQ-CC-CDMA) system, whose multi-carrier transmission is based on MLQ modulation to mitigate ISI and multi-user interference (MUI) with ideal auto- and cross-correlations of complementary codes. Compared to a frequency domain (FD) CC-CDMA system, MLQ-CC-CDMA has a lower RF complexity. Compared to OFDM direct sequence (DS) CDMA and single carrier frequency division multiple access (SC-FDMA) CDMA schemes, MLQ-CC-CDMA achieves a higher spectrum efficiency (SE) and a lower bit error rate with Rake and minimum mean square error (MMSE) detection due to its powerful multipath and multi-carrier diversity gains. [ABSTRACT FROM AUTHOR]

To develop the semiconductor of ZnO nanomaterials as the fluorescence sensor without leakage toxicity. Here, a molecularly imprinted polymer captivity ZnO nanorods (NRs) (MIPs-captivity ZnO NRs) was fabricated by precipitation polymerization. Such traditional technology was not only achieved the specific recognition for direct fluorescent quantification of the target tetracycline (TC) through fluorescence quenching, but also formed the shield to reduce the toxic effects of ZnO towards organisms. Under the optimized experimental conditions, the MIPs-captivity ZnO NRs were effectively applied to the direct fluorescence quantification of TC with excellent stability. Moreover, the practical analytical performance of the MIPs-captivity ZnO NRs was assayed by appraising the detection effects of TC in water sample from the Yangtze River with satisfactory results. A MIPs-captivity ZnO fluorescent sensor was prepared for the sensitive and selective detecting TC with excellent stability in environmental water samples. Unlabelled Image • A semiconductor ZnO nanorods (NRs) was captivated with molecularly imprinted polymer (MIPs) by precipitation polymerization. • The MIPs-captivity ZnO NRs showed the selective recognition and sensitive detection to tetracycline with excellent stability. • The MIPs-captivity ZnO NRs can be applied to assay practical environmental water sample with satisfactory results. [ABSTRACT FROM AUTHOR]

Exploring semiconductor-based photocatalysis toward reaching solar energy conversion was an ideal strategy. Here, Ni(OH) 2 was used an effective co-catalyst instead of noble metal to construct a novel two dimensional 2D/2D Ni(OH) 2 /Bi 4 Ti 3 O 12 composites with interfacial interaction between Ni(OH) 2 and Bi 4 Ti 3 O 12. The layer Ni(OH) 2 /Bi 4 Ti 3 O 12 composites showed higher photocatalytic activity as compared to pure samples, which was attributed to the interfacial interaction to promote the electron-holes separation. Thus, this work provided a novel insight into design 2D/2D nanocomposites and proved Ni(OH) 2 could excellently act as the effective co-catalyst instead of noble metal to enhance photocatalytic activity. • An efficient co-catalyst of Ni(OH) 2 instead of noble metal to modify Bi 4 Ti 3 O 12. • A new 2D/2D layer-like Ni(OH) 2 /Bi 4 Ti 3 O 12 composites were constructed. • The interfacial interaction and 2D coupling interfaces, promoting the electron-holes separation. [ABSTRACT FROM AUTHOR]

This work focused on the utilization of biological extract for the preparation of lignin-based carbon composites materials and used in the field of photocatalysis. A straightforward one-step carbonization way has been developed to prepare vanadium-doped lignin-based carbon/Bi 2 O 3 composites photocatalyst by using sodium lignosulfonate as the carbon source and catalyst. The application of lignin as the carbon source to form photocatalyst support tends to control the uniform distribution. At the same time, sodium lignosulfonate as the catalyst could break down the BiVO 4 during carbonization process. A series of characterizations demonstrated the BiVO 4 was transformed into Bi 2 O 3 and vanadium-doped lignin-based carbon. The possible synthesis process was proposed. Moreover, the novel V-doped carbon/Bi 2 O 3 composites photocatalyst displayed higher photocatalytic activity than bare BiVO 4. A possible photocatalytic mechanism was also discussed. This work provided new insight into the lignin-based carbon materials. • One-step carbonization for preparing novel V-doped lignin-based carbon/Bi 2 O 3 composites. • The biological extract of sodium lignosulfonate lignin both as the carbon source and catalyst to form carbon supporter and decomposition of BiVO 4. • The V played as the trapping centers in the lignin-based carbon for effectively separation of electron-hole pairs. [ABSTRACT FROM AUTHOR]

The detection of o-nitrophenol in the environment is of great significance to environmental protection. In this paper, the fluorescence sensor of CsPbBr3@SHFW was synthesized by an ultrasonic assisted method using perovskite quantum dots as the fluorescence source and a super hydrophobic porous organic polymer framework (SHFW) as the protective layer. Then CsPbBr3@SHFW was used to detect o-nitrophenol in dichloromethane. Under the optimum conditions, the detection limit of CsPbBr3@SHFW was 7.69 × 10−3 μM, and the linear range was 0–280 μM. It was also proved that the fluorescence quenching of this work is electron transfer. This work provided help for the construction of a stable perovskite quantum dot sensor and the application of a perovskite quantum dot sensor in the field of fluorescence detection. [ABSTRACT FROM AUTHOR]

• 0D CuInS 2 enhanced the photocatalytic performance of 2D NiAl-LDH. • Large BET surface and efficient separation of photo-induced electron-hole pairs. • A band matching within the n-n junction for efficient internal charge transfer. 0D/2D interface heterostructure of 0D CuInS 2 and 2D NiAl-LDH were obtained via strong interfacial contact. Mott-Schottky analysis confirmed both materials were n-type feature. Thus, a staggered n-n heterojunction was formed via the balance of Fermi level. This 0D/2D composite exhibited enchantable activity for photocatalytic degradation 2,4-Dichlorophenol under visible-light illumination, far superior than pure CuInS 2 and NiAl-LDH. The improvement of photocatalytic performance mainly attributed to the large BET surface area and interfacial contact, which resulted in more active sites, effective charge separation and transfer. Moreover, the optimal CuInS 2 /NiAl-LDH composite showed higher photostability for cycle experiments. At the same, the possible photocatalytic reaction process was proposed based on the trapping experiments, ESR technique and band position. This work provided a theory and foundation for designing and preparing of 0D/2D heterostructure system for photocatalytic application. [ABSTRACT FROM AUTHOR]

A handle on annulation: The two alkenoyl moieties of the cyclic dithiolane are parallel to each other and enables the [7C+1C] annulation with ethyl isocyanoacetate to occur. As a result, tricyclic indolizidine alkaloids are constructed by a two‐step, base‐catalyzed [7C+1C] annulation/intramolecular cyclization with subsequent reduction/cyclization. [ABSTRACT FROM AUTHOR]

Die beiden parallelen Alkenoyleinheiten des abgebildeten cyclischen Dithiolans ermöglichen eine [7C+1C] ‐ Anellierung mit Isocyanessigsäureethylester. Somit sind tricyclische Indolizidin ‐ Alkaloide in zwei Stufen durch basekatalysierte [7C+1C] ‐ Anellierung/intramolekulare Cyclisierung mit anschließender Reduktion/Cyclisierung zugänglich. [ABSTRACT FROM AUTHOR]

An interface conductive TiO 2 (B)/GO/ZIF-8 composite photocatalyst was successfully designed, which not only offer carrier to enhance the stability and connection, but also acted as center of electron transfer to migrate electrons and reduced the recombination of e--h+ pairs. [Display omitted] • The TiO 2 (B)/GO/ZIF-8 composite was prepared successfully through in situ water-bath method. • The photocatalytic activity of TiO 2 (B)/GO/ZIF-8 composite was improved compared with pure TiO 2 (B) and ZIF-8. • The reactive O 2 − and h+ played the major roles in the IBP degradation. • The embedded GO effectively reduced the resistivity and improves the photocurrent. Photocatalytic technology was environmentally friendly and efficient, which have attracted much attention on solving environmental pollution. To develop visible-light driven photocatalyst with high activity, this paper to report a series of black titanium dioxide/graphene oxide/metal–organic framework (TiO 2 (B)/GO/ZIF-8) composite was synthesized and characterized by various method. The results exhibited that TiO 2 (B)/GO/ZIF-8 composite with high catalytic activity for degrading Ibuprofen (IBP) can be obtained through introduction of GO. The increased photocatalytic performance of TiO 2 (B)/GO/ZIF-8 was benefit from the electronegativity and strong light absorption. The results indicated that TiO 2 (B)/GO/ZIF-8 can act as suitable photocatalytic materials. [ABSTRACT FROM AUTHOR]

Influenza is a clinically important infectious disease with a high fatality rate, which always results in severe pneumonia. Mesenchymal stem cells (MSCs) exhibit promising therapeutic effects on severe viral pneumonia, but whether MSCs prevent virus infection and contribute to the prevention of influenza remains unknown. ICR mice were pretreated with human umbilical cord (hUC) MSCs and then infected with the influenza H7N9 virus. Weight, survival days, and lung index of mice were recorded. Serum antibody against influenza H7N9 virus was detected according to the hemagglutination inhibition method. Before and after virus infection, T cell and B cell subtypes in the peripheral blood of mice were evaluated by flow cytometry. Cytokines in the supernatants of MSCs, innate immune cells, and mouse broncho alveolar lavage fluid (BALF) were determined by enzyme-linked immunosorbent assay (ELISA) or Luminex Assay. Pretreatment with MSCs protected mice against influenza H7N9 virus infection. Weight loss, survival rate, and structural and functional damage to the lungs of infected mice were significantly improved. Mechanistically, MSCs modulated T lymphocyte response in virus-infected mice and inhibited the cGAS/STING pathway. Importantly, the protective effect of MSCs was mediated by cell-to-cell communications and attenuation of cytokine storm caused by immune overactivation. • The prevention of MSCs on H7N9 virus infection and exploring the protective effect of MSCs in other viral infections. • Instead of direct differentiation, MSCs play an immunomodulatory role through cell-to-cell communications after pretreatment. • MSCs inhibit the cGAS-Sting pathway for the suppression of cytokine storm induced by excessive immune activation. [ABSTRACT FROM AUTHOR]

• CsPbBr 3 QDs were successfully adhered to BN nanosheets by an easy heterogeneous nucleation method. • The improving stability of CsPbBr 3 @BN sensor was realized by the protection of BN nanosheets for CsPbBr 3 QDs. • The fluorescence of CsPbBr 3 @BN sensor could be sensitively quenched by tetracycline through electron transfer process. The abuse of tetracycline (TC) antibiotics would seriously affect human health and hence the detection had become essential. Here, we had constructed a hydrophobicity of fluorescence sensor based on the excellent photoluminescence emission of CsPbBr 3 QDs and the hydrophobic ability of Boron Nitride (BN). This design effectively solved the instability of CsPbBr 3 QDs and realized the sensitive detection of TC. Under optimum conditions, the linear range of TC was 0–0.44 mg L−1 with the 6.5 μg L−1. Furthermore, the sensor was successfully used for the recognition of TC in honey and milk samples. This work also provided an ideal for designing CsPbBr 3 QDs-based on fluorescence sensor. [ABSTRACT FROM AUTHOR]

In this paper, we prepared a fluorescent sensor based on carbon quantum dots (CDs) and molecularly imprinted technology (MIT) that was successfully synthesized and applied to the detection of aspirin (Asp) residues in biological and pharmaceutical samples. The molecularly imprinted fluorescence sensor had the high sensitivity of quantum dots and the high selectivity of molecularly imprinted polymers (MIPs). Nitrogen-doped carbon quantum dots (N-CDs) with high fluorescence intensity were prepared and then was coated with silicon by the reverse microemulsion method. Finally, 3-aminopropyltriethoxysilane (APTES) was used as the functional monomer and Asp as the template molecule, molecularly imprinted layers were formed around the N-CDs. Under the best experimental conditions, the detection limit of the sensor was 0.198 mg L − 1 . Between 0.9–9.0 mg L − 1 , this fluorescence sensor had a good linear relationship with the concentration of Asp. To test the practicability of the sensor, we used this fluorescent sensor to detect Asp in human urine and saliva. Satisfied recovery rate between 101.1–105.1% and 102.1–106.0% were obtained, respectively. In this paper, a molecularly imprinted fluorescence sensor was prepared by the inverse microemulsion method. Fluorescence quenching method based on molecularly imprinted fluorescence sensor was used to determine the content of Asp. When Asp combined with N-CDs@SiO2@MIPs, the fluorescence of N-CDs was quenched. The experimental results showed that the molecularly imprinted fluorescent sensor could quickly and accurately detect Asp residues in human urine and saliva. [ABSTRACT FROM AUTHOR]

• Carbon materials was obtained from green tea and acted as the electron transfer medium to effectively enhance photocatalytic performance. • Charge was transferred through dual paths. • The Ni 2 P and CDs were all acted as the active sites for improving the photocatalytic performance. Carbon materials can act as electron transfer media to effectively enhance photocatalytic performance. In this study, carbon dots (CDs) were prepared using green tea to modify Ni 2 P/NiCo-LDH heterostructures. Benefitting from the Co-P bond formed between Ni 2 P and NiCo-LDH and biomass CDs, charge transfer was improved via dual channel. Ni 2 P and CDs acted as active sites for improving the photocatalytic performance. Owing to the synergistic process, the photoresponse capability of CDs/Ni 2 P/NiCo-LDH was significantly increased. In addition, the possible active species in the photocatalytic process are discussed. This study provides a design for ternary photocatalysts with carbon materials and phosphides. [Display omitted] [ABSTRACT FROM AUTHOR]

• Specific sensors with tailor-made selective recognition sites to OTC were developed. • Ratiometric fluorescence sensors were successfully employed to detect OTC in milk. • The detection limit of the prepared fluorescence sensors was low to 3.5 nM. Ratiometric fluorescence imprinting sensors (GQDs/CdTe@MIPs) were successfully constructed by precipitation polymerization method for the recognition and detection of oxytetracycline (OTC) in milk samples. GQDs/CdTe@MIPs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), fourier transform infrared (FT-IR), thermal gravity analysis (TGA), UV–visible spectroscopy (UV–vis) and X-ray photoelectron spectroscopy (XPS) techniques. A satisfying linear relationship under 0–80 μM OTC concentration (R2 = 0.99699) was exhibited. High sensitivity was showed with the limit of detection of 3.5 nM and high recovery ranged from 99.93% to 100.20%. In addition, the selectivity of GQDs/CdTe@MIPs to OTC was well comparing with other antibiotics. With the injection of different concentrations of OTC, the fluorescent color change of GQDs/CdTe@MIPs under the 365 nm UV lamp further verified that GQDs/CdTe@MIPs were used successfully for the visual detection to OTC in milk samples. [ABSTRACT FROM AUTHOR]

A novel, sensitive sensor material combined the technique of surface enhance Raman scattering (SERS) and molecular imprinting was prepared. It was used the amino-functionalized SiO 2 nanospheres as the supporting materials and anchored Ag nanoparticles on the surface by the function of coordination between Ag + and NH 2 − . Then, it was used that the Rhodamine 6G (R6G) as the template, acrylamide (AM) as functional monomer, ethyleneglycol dimethacrylate (EGDMA) as cross-linker, 2,2′-azobis(2-methylpropionitrile) (AIBN) as initiator to prepare the core-shell molecular imprinted polymers. Prominently, the shell thickness could be controlled by the regulation of cross-linker dosage and it was found that the SERS detection signal was most obvious when the shell thickness was about 40 nm. Under the optimal condition, it was presented good linear relationship (R 2 = 0.93) between the Raman signal (at 1505 cm −1 ) and the concentration of the templates and the limit of detection was 10 −12 mol L −1 . Meanwhile, the selective experiment was proved that this materials owned specific selectivity to the template. It was confirmed that the core-shell molecular imprinted polymers were a kind of highly sensitive and selective sensor materials in the field of R6G detection. [ABSTRACT FROM AUTHOR]

Novel molecularly imprinted polymers (MIPs) based on the technique of surface-enhanced Raman scattering (SERS) were successfully prepared. Firstly, ZnO nanorods were fabricated with Ag by reduction of Ag on the surface of the ZnO nanorods. Then, ZnO/Ag heterostructures were used as the substrate, rhodamine 6G was used as the template molecule, acrylamide was used as the functional monomer, ethylene glycol dimethacrylate was used as the cross-linker, and 2,2′-azobis(2-methylpropionitrile) was used as the initiator to prepare the ZnO/Ag MIPs (ZOA-MIPs). Through characterization analysis, it was proved that the novel ZOA-MIPs exhibited excellent SERS properties and selectivity. Under the optimal conditions, there was a good linear relationship ( R = 0.996) between the Raman signal (at 1654 cm) and the concentration of the templates, and the detection limit was 10 mol L. It was also proved that the ZOA-MIPs had the property of self-cleaning, resulting in good reusability. It is envisaged that the sensitivity of SERS coupled with the selectivity of MIPs could result in a promising chemosensor for practical applications. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Facile [7C + 1C] Annulation as an Efficient Route to Tricyclic Indolizidine Alkaloids" by X. Liu, L. Zhang, L. Pan and others, published in the "Angewandte Chemie International Edition" in 2013.

• Traditional methods to study leukemia stem cells have potential pitfalls. • The mRNAsi index could avoid these potential pitfalls via machine learning. • We generated differential expression genes by data from the TCGA and GTEx databases. • We constructed the first gene network of leukemia stem cells. • RFC4 and RFC5 were screened as prognostic stemness genes and validated by the TCGA and GEO databases. Traditional methods to understand leukemia stem cell (LSC)'s biological characteristics include constructing LSC-like cells and mouse models by transgenic or knock-in methods. However, there are some potential pitfalls in using this method, such as retroviral insertion mutagenesis, non-physiological level gene expression, non-physiological expansion, and difficulty to construct. The mRNAsi index for each sample of the Cancer Genome Atlas (TCGA) could avoid these potential pitfalls by machine learning. In this work, we aimed to construct a network of LSC genes utilizing the mRNAsi. First, mRNAsi value was analyzed with expressions distributions, survival analysis, age, and gender in acute myeloid leukemia (AML) samples. Then, we used the weighted gene co-expression network analysis (WGCNA) to construct modules of stemness genes. The correlation of the LSC genes transcription and interplay among LSC proteins was analyzed. We performed functional and pathway enrichment analysis to annotate stemness genes. Survival analysis further identified prognostic biomarkers by clinical data of TCGA and the Gene Expression Omnibus (GEO) database. We found that the result of mRNAsi overall survival is not significant, which may be due to the heterogeneity of AML in the stage of myeloid differentiation, French–American–British (FAB) classification systems. Enrichment analysis indicated that the stemness genes were biologically clustered as a group and mainly associated with cell cycle and mitosis. Moreover, 10 key genes (SNRNP40, RFC4, RFC5, CDC6, HSPE1, PA2G4, SNAP23P, DARS2, MIS18A, and HPRT1) were screened by survival analysis with the data from TCGA and GEO. Among them, RFC4 and RFC5 were the distinguished biomarkers for their double-validated prognostic value in both databases. Additionally, the expression of RFC4 and RFC5 had the same trend as mRNAsi score in FAB subtypes. In conclusion, our result demonstrated that mRNAsi based LSC-related genes were found to have strong interactions as a cluster. These genes, especially RFC4 and RFC5, could be the therapeutic targets for inhibiting the stemness characteristics of AML. This work is also a comprehensive pipeline for future cancer stem cell studies. [ABSTRACT FROM AUTHOR]

Abstract [ABSTRACT FROM AUTHOR]

A series of novel non-precious-metal-based composite photocatalysts was developed using layered double hydroxide (NiCo-LDH) and transition metal phosphide (Ni 2 P) to explore the performance of high-efficiency photocatalytic composite materials containing no precious metals. The developed Ni 2 P/NiCo-LDH composites displayed an enhanced photocatalytic performance under visible-light illumination. Further researches confirmed that a unique Co–P bond, which led to an increased light absorption, was formed in the composites. Importantly, this unique Co–P bond reduced the interface transfer resistance of the Ni 2 P/NiCo-LDH composites, enhanced their charge separation efficiency, and formed a rapid charge transport channel between Ni 2 P and NiCo-LDH in the composites to provide improved photocatalytic activity. Additionally, a mechanism was proposed for the further exploration of non-precious metal-based composites. The study provides novel insight into the research on the use of non-precious metal materials and NiCo-LDH in the field of photocatalysis. Image 1 • The Ni 2 P/NiCo-LDH is a composite photocatalyst containing no precious metals. • The Co–P bond accelerated the separation and transfer of photogenerated carriers as a charge transfer channel. • Proposed a possible charge transport mechanism for degradation of tetracycline under visible light. [ABSTRACT FROM AUTHOR]