Search

Three types of α-Mn2O3 catalysts with different well-defined morphologies (cubic, truncated octahedra and octahedra) and exposed crystal facets have been successfully prepared via hydrothermal processes, and evaluated for ethanol total oxidation with low ethanol concentration at low temperatures. The α-Mn2O3-cubic catalyst shows a superior catalytic reaction rate than that of α-Mn2O3-truncated octahedra and α-Mn2O3-octahedra under high space velocity of 192,000 mL/(g·h). Based on the characterization results obtained from XRD, BET, FE-SEM, HR-TEM, FT-IR, H2-TPR, XPS, ethanol-TPD, and CO-TPSR techniques, the observed morphology-dependent reactivity of α-Mn2O3 catalysts can be correlated to the good low-temperature reducibility, abundant surface Mn4+ and adsorbed reactive oxygen species, which was originated from the exposed (001) crystal planes. Through tuning the morphology and exposed (001) crystal facet of α-Mn2O3, a highly active ethanol oxidation catalyst with high selectivity and excellent stability is obtained. The developed approach may be applied broadly to the development of the design principles for high-performance low-cost and environmentally friendly Mn-based oxidation catalysts.

The entry vehicle for the Tianwen-1 mission successfully landed on the surface of Mars at 7:18 AM BJT on May 15, 2021. This successful landing made China the first country to orbit, land, and release a rover in their first attempt at the Mars exploration. The guidance, navigation, and control (GNC) system plays a crucial role in the entry, descent, and landing (EDL) phases. This study focused on the attitude control component of the GNC system design. The EDL phase can be divided into several sub-phases, namely the angle of attack control phase, lift control phase, parachute descent phase, and powered descent phase. Each sub-phase has unique attitude control requirements and challenges. This paper introduces the key aspects of designing attitude controllers for each phase. Furthermore, flight results are presented and analyzed.

Hepatocellular carcinoma (HCC) is one of the principle causes of cancer-associated death throughout the world. However, the patients with HCC are insensitive to traditional drugs and lack effective therapeutic drugs. Dysregulation of Hippo-YAP signaling is closely associated with HCC. Bortezomib (BTZ) is mainly used in clinical multiple myeloma. It has recently been confirmed that bortezomib could suppress cell proliferation in many different types of cancer. Nevertheless, the precise effects of bortezomib on hepatocellular carcinoma and its possible interactions with the Hippo-YAP signaling pathway in HCC cells remain largely unknown. In this study, HCC cell lines (HepG2 and Huh 7) and nude mice with xenograft tumors were used to evaluate the influences of bortezomib. Furthermore, we focused on exploring whether bortezomib exerts its anti-HCC effect through the Hippo-YAP signaling pathway and aimed to lay a theoretical foundation for bortezomib as a potential therapeutic drug for hepatocellular carcinoma. Herein, our results disclose a new mechanism of bortezomib in controlling the cell growth of HCC. Bortezomib down-regulates the level of YAP by promoting LATS1 expression to inhibit the growth of HCC cells, which leads to the phosphorylation of YAP and limits YAP nuclear translocation. In sum, our data confirmed that the Hippo-YAP signaling pathway mediates the anti-HCC effects of bortezomib.

All-inorganic halide perovskites, as a dominant member of the perovskite family, have been proven to be excellent semiconductors due to the great successes for solar cells, light-emitting diodes, photodetectors, and nanocrystal photocatalysts. Despite the remarkable advances in those fields, there are few research studies focusing on gas and humidity-sensing performances, especially for pure CsPbBr

Rationale: Precise treatment of tumors is attracting increasing attention. Molecular probes simultaneously demonstrating the diagnostic signal and pharmacological effect in response to tumor microenvironment are highly desired. γ-glutamyl transpeptidase (GGT) is a biomarker with significantly up-regulated expression in the tumor area. We developed a GGT responsive near-infrared (NIR) nanoassembly for tumor-specific fluorescence imaging-guided photothermal therapy. Methods: The GGT responsive NIR probe was constructed by conjugating GGT-specific substrate γ-glutamic acid (γ-Glu) with cyanine fluorophore (NRh-NH2) via amide reaction. The resulting NRh-G spontaneously assembled into nanoparticles (NRh-G-NPs) around 50 nm. The NPs were characterized and the properties evaluated in the presence or absence of GGT. Subsequently, we studied fluorescence imaging and photothermal therapy of NRh-G-NPs in vitro and in vivo. Results: NRh-G-NPs, upon specific reaction with GGT, turned into NRh-NH2-NPs, showing a ~180-fold fluorescence enhancement and excellent photothermal effect recovery. NRh-G-NPs could selectively light up U87MG tumor cells while their fluorescence was weak in L02 human normal liver cells. The NPs also showed excellent tumor cell ablation upon laser irradiation. After intravenous injection into tumor-bearing mice, NRh-G-NPs could arrive in the tumor area and specifically light up the tumor. Following laser irradiation, the tumor could be completely erased with no tumor reoccurrence for up to 40 days. Conclusions: NRh-G-NPs were specifically responsive to GGT overexpressed in U87MG tumor cells and selectively lit up the tumor for imaging-guided therapy. Besides, the recovery of photothermal property in the tumor area could improve cancer therapy precision and decreased side effects in normal tissues.

Phototherapy has developed as a powerful method for remedial modalities. The conventional photosensitizers are "always on" state and lack tumor targeting, which contributed to poor therapeutic effect and high toxicity. Therefore, we developed an aspartyl aminopeptidase (DNPEP) activated self-assembled organic nanoparticles (NRh-Asp NPs) with sensitive external irradiation-induced photothermal therapy and photodynamic therapy (PTT/PDT). NRh-Asp NPs can be activated to NRh-NH

Hypoxia is an obvious characteristic of cancer, especially solid tumors. which may give rise to the expansion of invasion and metastasis. Exploring near-infrared (NIR) nanoprobes that could accurately evaluate the degree of hypoxia will contribute to the assessment of the degree of malignant neoplasms, so as to adopt more accurate and individualized treatment options Here, we have developed a self-assembled NIR organic nanoprobe to specifically and authoritatively detect the oxygen concentration

The thermophoresis of suspended particles in a fluid is usually from high to low temperature. In the present paper, the negative thermophoresis (from low to high temperature) of nanoparticles in liquids is investigated by molecular dynamics simulations. It is found that the solid–liquid intermolecular coupling strength has a significant effect on the direction and magnitude of the thermophoretic force. Positive thermophoresis can be observed for strong couplings, while negative thermophoresis emerges for weak couplings. The negative thermophoresis is induced by the density gradient which pushes the particle from high to low density. Based on the analysis of the potential mean force of the solid–liquid interfacial layer, it is revealed that the switch between positive and negative thermophoresis is associated with the sign change of the averaged potential mean force for the interfacial layer. Therefore, the sign of the averaged potential mean force can be used as a criterion to predict the occurrence of negative thermophoresis. The results of this work provide insights for the microscopic manipulation of nanoparticles.

Hydrogen sulfide (H2S) is a significant gasotransmitter. A deficiency in H2S might contribute to some serious diseases. The development of H2S drugs has received a great deal of attention. There is a pressing need for an effective method to evaluate H2S release efficiency, especially in in vivo evaluation. In this study, a highly sensitive and selective near-infrared (NIR) fluorescent chemodosimeter (NRh-N3) was synthesized for detecting H2S. Importantly, NRh-N3 was shown to be capable of visually monitoring H2S-release from the prodrug in vitro and in vivo.

Further development of high-efficiency and low-cost organic fluorescent materials is intrinsically hampered by the energy gap law and spin statistics, especially in the near-infrared (NIR) region. Here we design a novel building block with aggregation-induced emission (AIE) activity for realizing highly efficient luminophores covering the deep-red and NIR region, which originates from an increase in the orbital overlap and electron-withdrawing ability. An organic donor–acceptor molecule (BPMT) with the building block is prepared and can readily form J-type molecular columns with multiple C–H⋯N/O interactions. Notably, such synthesized materials can emit fluorescence centered at 701 nm with extremely high photoluminescence quantum yields (PLQYs) of 48.7%. Experimental and theoretical investigations reveal that the formation of the hybridized local and charge-transfer (HLCT) state and substantial C–H⋯N/O interactions contribute to a fast radiative decay rate and a slow nonradiative decay rate, respectively, resulting in high PLQYs in the solid state covering the NIR range. Remarkably, such BPMT crystals, as a first example, reveal strong-penetrability piezochromism along with a distinct PL change from the deep-red (λmax = 704 nm) to NIR (λmax = 821 nm) region. Moreover, such typical AIE-active luminophores are demonstrated to be a good candidate as a lasing medium. Together with epoxy resin by a self-assembly method, a microlaser is successfully illustrated with a lasing wavelength of 735.2 nm at a threshold of 22.3 kW cm−2. These results provide a promising approach to extend the contents of deep-red/NIR luminophores and open a new avenue to enable applications ranging from chemical sensing to lasing., A HLCT-type luminophore is prepared with bright deep-red fluorescence, showing high-performance piezochromism and lasing.

Multimaterial fibers which integrate novel materials and/or structures into fiber configuration aim at developing multiple functionalities and high performance. Here, we demonstrate a kind of multimaterial fibers with crystalline GeSe core and K9 glass cladding by the molten core drawing method. The as-drawn fibers undergo a change in electrical conductivity when externally illuminated by an 808 nm HeNe laser. Furthermore, the Seebeck coefficient of the fibers is comparable with bulk GeSe, while the resistance is 3–4 magnitude lower than that. The results show that the GeSe core fibers have promising applications in optical switch and thermoelectric conversion field.

Bismuth selenide exhibits high thermoelectric performance, which is a promising candidate for thermal-electrical energy conversion. Here, Bi2Se3 core thermoelectric fibers with K9 glass cladding were fabricated by a molten core drawing method. The 50-μm-diameter Bi2Se3 core fibers exhibit an ultrahigh Seebeck coefficient of −150.85 μV/K. In addition, it has a high dimensionless figure of merit of 0.18 (at 300 K) and a long-term stability in air. The results indicate that the drawing approach is an effective way to fabricate high-performance and high-stability thermoelectric fibers, which will have potential application in fiber-integrated thermoelectric devices.

BackgroundHemangioblastoma in the kidney is rare. Although a few renal hemangioblastoma cases have been reported, the content of these articles mainly focused on clinical and pathological research, with minimal descriptions of radiologic findings. Moreover, there are no descriptions of magnetic resonance imaging with enhancement for this condition. We herein report two cases of renal hemangioblastoma with computed tomography and magnetic resonance imaging findings.Case presentationTwo patients presented to our institution due to dull pain of the left abdomen, and a mass in the left kidney was found by ultrasound examination in each case. They had no special family history. Physical examination revealed no obvious tenderness or percussion pain in the renal region and ureteral walking area, and there was no obvious mass. Routine blood and urine tests were normal, and serum tumor markers were negative. No obvious lesions were found on imaging of other body parts. Similar radiologic findings were observed in both cases and mimicked those of cavernous hemangiomas of the liver, including peripheral nodular enhancement in the corticomedullary phase, progressive centripetal enhancement in the nephrographic and delayed phases, and occasional complete “filling in” in the delayed phase. Given the suspicion for renal cell carcinoma, both patients underwent partial nephrectomy. The pathological results showed renal hemangioblastoma.ConclusionsRenal hemangioblastoma is a rare benign tumor that is easily misdiagnosed as clear cell carcinoma. Characteristic computed tomography and magnetic resonance imaging manifestations may improve preoperative diagnostic accuracy to avoid surgery or indicate nephron-sparing surgery.

Nano-heterojunctions play an important role in optimize semiconductor performances. Considering the different electron structure-related physical properties and their own sensing advantages of MoS2 and ZnO, we propose a noval semiconductor heterojunction based on MoS2/ZnO composites. Furthermore, the size and microstructure of the MoS2/ZnO composites are carefully designed by synthesis technique optimization. Here, the unique MoS2/ZnO bridge-like heterogeneous composite nanostructure composed of nanoflowers and nanosheets is prepared by two-step hydrothermal method. Further, MoS2/ZnO composites are characterized by using XRD, SEM, TEM, UPS and XPS. The MoS2/ZnO sensor is investigated for pollutant triethylamine (TEA) sensing applications. The gas sensitivity test shows remarkable response (31.08) to 100 ppm TEA at an optimum operating temperature (200 °C). Moreover, as compared with other interfering gases, it presents excellent selectivity to TEA and outstanding stability in air atmosphere within 5 weeks, besides the short response time (35 s) and recovery time (142 s) to 100 ppm TEA. The superiority of the sensor may be ascribed to the unique three-dimension self-assembly nanostructure and the formation of n-n heterojunctions. The MoS2/ZnO sensor with good performances verifies its good prospect in practical applications.

Hydrogen sulfide (H2S) is a significant gasotransmitter. A deficiency in H2S might contribute to some serious diseases. The development of H2S drugs has received a great deal of attention. There is a pressing need for an effective method to evaluate H2S release efficiency, especially in in vivo evaluation. In this study, a highly sensitive and selective near-infrared (NIR) fluorescent chemodosimeter (NRh-N3) was synthesized for detecting H2S. Importantly, NRh-N3 was shown to be capable of visually monitoring H2S-release from the prodrug in vitro and in vivo.

Organic microlasers have attracted much attention due to their unique features such as high mechanical flexibility, facile doping of gain materials, high optical quality, simplicity and low-cost fabrication. However, organic gain materials usually suffer from aggregation-caused quenching (ACQ), preventing further advances of organic microlasers. Here, a new type of microlaser from aggregation-induced emission (AIE) material is successfully demonstrated. By introducing a typical noncrystalline AIE material, a high quality microlaser is obtained via a surface tension-induced self-assembly approach. Distinct from conventional organic microlasers, the organic luminescent material used here is initially nonluminescent but can shine after aggregation under optical pumping. Further investigations demonstrate that AIE-based microlasers exhibit advantages to enable much higher doping concentrations, which provides an alternative way to improved lasing performance including dramatically reduced threshold and favorable lasing stability. It is believed that these results could provide a promising way to extend the content of microlasers and open a new avenue to enable applications ranging from chemical sensing to biology.

Acute liver injury (ALI) is one of the main causes of malignant liver disease. We developed a rhodamine-based frequency upconversion luminescent probe (NRh-NNBA) to detect the biomarker glutathione S-transferase (GSTs) to monitor ALI. NRh-NNBA showed a rapid and specific response to GSTs in drug-induced and CCl4-induced ALI, respectively, by generating the enzymatic product NRh-glutathione, which emitted at 832 nm under excitation at 850 nm. NRh-NNBA successfully detected endogenous GSTs in human liver L02 cells with a high signal-to-noise ratio, and detected GSTs activity levels in liver slices and serum from ALI mice. These results suggest that NRh-NNBA might serve as an ideal sensor for monitoring GSTs during the diagnosis and treatment of ALI.

Non-invasive and accurate detection of copper is essential to elucidate its functions. Herein, we report a mitochondria-targeted near-infrared probe (NFL-TPA) for bioimaging of copper. The probe exhibits high sensitivity and selectivity for copper(I) with low detect of limit (14.4 nM). More importantly, the probe can monitor the level of copper(I) in mitochondria, and successfully detect the distribution of copper(I) in living mice by near infrared fluorescence (NIR) imaging in vivo and ex vivo. Furthermore, the probe could assess the therapeutic efficiency of d -penicillamine. Thus, the probe motivates the development of novel NIR platform for copper(I) detection and drug evaluation.

Tin selenide (SnSe) exhibits high thermoelectric (TE) performance, which is a promising TE candidate for thermal-electrical energy conversion. In this work, Sn-Se alloy core borosilicate glass-clad fibers with ∼94 μm core and ∼220 μm cladding in diameter were fabricated by a molten core drawing method. X-ray diffraction (XRD) showed the core to be highly crystalline and consist of SnSe and SnSe2 poly-crystal grains. Based on EPMA measurement, there exists an inter-diffusion process between the core and cladding ions during the fiber drawing. The Seebeck coefficient of the Sn-Se core is −151 μV/K. The electrical conductivity of the Sn-Se core is as high as 6.2 × 103 S/m, which is close to that of SnSe single crystals. The demonstration of fibers with TE core materials and the integration with the conventional fiber fabrication technique represents the first step in providing the building blocks for fiber-integrated TE devices.

Aerogels are usually synthesized from supercritical drying of wet-gels. High quality aerogels are usually characterized with high specific surface area (measured by BET method here) and high degree of polymerization of silicate (characterized by 29 Si NMR here). The quality of the aerogels depends highly on the quality of the corresponding wet-gels because the skeletal structure in the wet-gels changes only slightly in the supercritical drying process. Here we present a simple method to predict the quality of the desired silica aerogels before the supercritical drying. We found that the relative optical transmittance of the silica wet-gels at 500 nm had good linear correlation with the specific surface area and the degree of silicate polymerization in the corresponding aerogels. We can assess the quality and screen out the low-quality wet-gels from supercritical drying operation, and greatly reduce the cost for aerogel production.

The target of this work is to survey the consequences of various B (B Fe, Co) sites of SmBO3 perovskite on crystal structure and ethylene glycol gas-sensitive properties. To this end, two samples based on SmFeO3 and SmCoO3 nanofibers with orthorhombic phase were prepared by a straightforward and efficient electrospinning technique and calcined at 700 °C. The XRD Rietveld refinements and tolerance factor (t) were implemented to research the crystal structure by the lattice parameters, size of B O B angles and t value, BET test shows that as-prepared two samples own different pore sizes, and XPS analyzes the composition and chemical state toward two samples, which indicates that more oxygen vacancies exist in SmFeO3 surface. Then, the gas-sensing performance of SmFeO3 and SmCoO3 nanofibers were compared at their optimal working temperature of 200 °C. The gas-sensing inquiries exhibit that the response of sensor based on SmFeO3 nanofiber (14.3) is almost 6.5 times higher than that of SmCoO3 (2.2) toward 100 ppm ethylene glycol. Finally, the sensing mechanisms of SmFeO3 and SmCoO3 nanofibers were also explained based on pore size, oxygen vacancy, lattice distortion and electrical conductance.

At present, gas sensors have promising prospects in terms of gas monitoring. Heterostructure with high carrier transport property is an alternative strategy to enhance the gas sensitivity. Herein, we directly transformed ZnSn(OH)6 microspheres to obtain SnS2/ZnS heterostructures through a low-cost hydrothermal treatment. Hierarchical SnS2/ZnS flowerlike microspheres consisting of ultrathin nanoflakes subunits were successfully synthesized without any impurities. The more attractive finding is the great improvement of triethylamine gas-sensing properties of the SnS2/ZnS composite compared to the pure SnS2 at 180 °C. Especially, the proposed SnS2/ZnS sensor demonstrates ultrafast responding and recovering time (2/8 s) to 50 ppm TEA. Such significantly enhanced sensing properties can be ascribed to the merit of heterojunction and high specific surface area provided by flakes-assembled flowerlike structure. Moreover, the convenient synthetic route paves the way to the future design of various heterojunctions for diverse gas detection.

Pr-doped SnO2 hollow beaded tubular nanostructure was synthesized by electrospinning technique, accompanied by using carbon spheres as sacrificial templates. The crystalline phase, morphology, microstructure, and element composition of the samples were explored and analyzed. The gas sensitivity test results show that Pr-doped SnO2 sensor exhibits high response value, excellent selectivity and rapid response-recovery ability to ethanol at 200 °C. The sensor can effectively detect ethanol vapor as low as 2 ppm. Response/recovery time to 100 ppm ethanol are about 12 s/8 s, respectively. The possible enhancement mechanism caused by the synergistic effect of the unique nanostructure, the carbon templates, and Pr dopant are discussed. The research may provide a better design of ethanol sensors.

Accurate detection of HOCl with high sensitivity and high selectivity is essential to elucidate its functions in health or disease states. Herein we propose a new fluorescence HOCl probe (NFL-S) by combining reasonable design strategies and dye screening methods. The probe NFL-S has fast response rate, excellent sensitivity (LOD = 35.0 nM) and outstanding selectivity toward HOCl. It has been successfully applied to detect endogenous HOCl produced by RAW264.7 cells, and further applied to oxidative stress imaging in a mouse arthritis model. Therefore, the probe NFL-S is highly promising to be useful for biological tool to disclose the roles of HOCl in different physiological and pathological contexts.

A convenient two-step hydrothermal method was used to prepare unique hierarchical MoS2/ZnO composites composed of porous microspheres and nanosheets. The gas sensing properties of MoS2/ZnO composite sensor was investigated. Compared with pure MoS2, the MoS2/ZnO composite sensor shows a remarkably increased response of 23.57 to triethylamine (TEA). In addition, the much shorter recovery time for MoS2/ZnO sensor is a sharp contrast to the terribly bad desorption ability of pure MoS2. The prepared MoS2/ZnO gas sensor can achieve a recovery rate of over 90 % after 134 s without using auxiliary means. The composite material also presents strong anti-interference ability and outstanding selectivity. The excellent sensing performances of MoS2/ZnO composite sensor may be attributed to the n-n composite heterojunction and the abundant diffusion channels originated from the unique microstructure. Our research work may provide a valuable strategy for preparing high-performance TEA sensor with low-cost.

Detecting sentiment of sentences in online reviews is still a challenging task. Traditional machine learning methods often use bag-of-words representations which cannot properly capture complex linguistic phenomena in sentiment analysis. Recently, recursive autoencoder (RAE) methods have been proposed for sentence-level sentiment analysis. They use word embedding to represent each word, and learn compositional vector representation of phrases and sentences with recursive autoencoders. Although RAE methods outperform other state-of-the-art sentiment prediction approaches on commonly used datasets, they tend to generate very deep parse trees, and need a large amount of labeled data for each node during the process of learning compositional vector representations. Furthermore, RAE methods mainly combine adjacent words in sequence with a greedy strategy, which make capturing semantic relations between distant words difficult. To solve these issues, we propose a semi-supervised method which combines HowNet lexicon to train phrase recursive autoencoders (we call it CHL-PRAE). CHL-PRAE constructs the phrase recursive autoencoder (PRAE) model at first. Then the model calculates the sentiment orientation of each node with the HowNet lexicon, which acts as sentiment labels, when we train the softmax classifier of PRAE. Furthermore, our CHL-PRAE model conducts bidirectional training to capture global information. Compared with RAE and some supervised methods such as support vector machine (SVM) and naive Bayesian on English and Chinese datasets, the experiment results show that CHL-PRAE can provide the best performance for sentence-level sentiment analysis.

A new type of thermally sensitive fibers with an antimony selenide (Sb 2 Se 3 ) core and phosphate glass cladding is demonstrated. The fibers were fabricated by a molten core method and maintained overall diameters ranging from 250 to 800 μm and core diameters of 35–200 μm. A 2.8 cm long Sb 2 Se 3 core fiber, electrically contacted to external circuitry through fiber end facets, exhibited a four orders of magnitude change in conductivity after the whole fiber was heated from 25 to 195 °C. In addition, the fiber exhibited enhanced photoconductivity under illumination. These results indicate that Sb 2 Se 3 core multimaterial fibers have promising applications in temperature sensing, optical switches and photodetectors.

Highly rare earth ions (RE-ions) doping phosphate glass fiber makes it possible to obtain high gain and high output power per unit length. However, high concentrations of RE-ions will cause concentration quenching and crystallization during the conventional rod-in-tube fiber drawing process. In this work, highly Er 3 + /Yb 3 + co-doped multi-component phosphate glasses were prepared by the melt-quenching method. Through thorough investigation of 1.53 μm luminescent properties of the glasses, optimal RE-ions were ascertained. The Er 3 + and Yb 3 + doping concentrations reach as high as 13.77 × 10 20 and 2.295 × 10 20 ions/cm 3 , respectively. Then the silicate-clad highly Er 3 + /Yb 3 + co-doped phosphate core multimaterial fibers were successfully fabricated by a molten core method. The multimaterial fibers have a large refractive index difference and good interface between the phosphate glass core and silicate glass cladding. An intense 1.53 μm emission was obtained from the multimaterial fiber. The results indicate that the highly Er 3 + /Yb 3 + co-doped multimaterial fibers are promising in applications that require high gain and high power from a short piece of active optical fiber.

In4Se3 exhibits high thermoelectric performance as a typical example of semiconductors, which is a promising thermoelectric candidate for energy conversion applications. Here, InSe alloy core thermoelectric fibers with glass cladding were fabricated by a reactive molten core drawing method. The as-drawn fiber core was found to be InSe crystals as evidenced by X-ray diffraction. The In4Se3 crystals were obtained in the fiber core by annealing the as-drawn fibers. The Seebeck coefficient of the In4Se3 core fibers (−347 μV/K) was enhanced by ∼85% compared with that of the as-drawn InSe core fibers (−189 μV/K). This work constitutes a proof-of-concept that thermoelectric materials can be incorporated into fibers, which have promising applications in fiber-based thermoelectric devices.

Solution-processed organo-lead halide perovskites have emerged as promising optical gain media for tunable coherent light sources. The lasing performance is generally determined by the as-synthesized crystal quality. Noble metal nanostructures have been widely utilized to enhance optical responses due to their unique property of localized surface plasmon resonance. Herein, we report a simple method to enhance the near-infrared amplified spontaneous emission (ASE) performance of MAPbI3 polycrystalline films by solution-processing a PMMA spacer layer and an Au NR-doped PMMA top layer on perovskite thin films. As a result, the ASE threshold of the triple-layer perovskite film was significantly reduced by around 36% and the ASE intensity increased by 13.9-fold, compared to the pristine film. The underlying mechanism was attributed to the combined effects of surface passivation by PMMA and plasmon resonance enhancement of Au NRs. The passivation effect results in suppressing the nonradiative recombination and prolonging excited state decay, which have been investigated by transient absorption and pump–probe measurements. The plasmon effect is systematically studied through distance-dependent and spectra-dependent plasmon enhanced emission. The perovskite films with PMMA and Au NR coating showed great stability for 180 min under intense pulse laser continuous irradiation. The improved ASE performance still remained after leaving the film under the atmosphere for more than one month. We have successfully demonstrated a highly stable and sustained ASE output from MAPbI3 films under pulse laser excitation. This study provides a general approach for exploring plasmonic nanostructures in combination with polymers in the development and application of low-cost solution-processed semiconductor lasers.

Rationale Hemangioblastomas in the kidney are rare. Although a few cases of renal hemangioblastoma (RH) have been reported, the content of these articles mainly focused on clinical and pathological research, with minimal descriptions of radiologic findings. Moreover, there are no descriptions of magnetic resonance imaging (MRI) with enhancement of this condition. Herein, we report 2 cases of RH with computed tomography (CT) and MRI findings. Patient concerns Two patients presented to our institution because of dull pain in the left abdomen, and a mass in the left kidney was found by ultrasound examination in each case. The patient had no special family history. Physical examination revealed no obvious tenderness or percussion pain in the renal and ureteral walking areas, and there was no obvious mass. Routine blood and urine tests were normal, and the serum tumor markers were negative. No obvious lesions were found on imaging of the other body parts. Diagnosis Similar radiologic findings were observed in both cases and mimicked those of cavernous hemangiomas of the liver, including peripheral nodular enhancement in the corticomedullary phase, progressive centripetal enhancement in the nephrographic and delayed phases, and occasional complete "filling in" in the delayed phase. We made a radiologic diagnosis of renal clear cell carcinoma for patient 1 and suspected renal clear cell carcinoma for patient 2, but the pathological results showed RH. Interventions Given the suspicion of renal cell carcinoma, both patients underwent partial nephrectomy. Outcome The recovery of the two patients was uneventful, and there was no evidence of local recurrence or metastasis many years after surgery. Lessons RH is a rare benign tumor that can be easily misdiagnosed as clear cell carcinoma. Characteristic CT and MRI manifestations may improve preoperative diagnostic accuracy to avoid surgery or indicate nephron-sparing surgery.

We report the visible up-conversion, near to middle infrared luminescence, and energy transfer mechanism of Er 3+ /Ho 3+ co-doped barium gallo-germanate glasses under 980 and 1550 nm excitations, respectively. The 2.0 μm emission lifetime of the present glass is as high as 5.67 ms with the corresponding energy transfer efficiency of 70.0% from Er 3+ : 4 I 13/2 to Ho 3+ : 5 I 7 when pumped by 980 nm laser diode. In addition, the enhanced 2.0 μm emission is also obtained upon excitation of 1550 nm due to the efficient energy transfer from Er 3+ to Ho 3+ . Meanwhile, the calculated maximum gain is 2.13 cm −1 at 2024 nm. These results suggest that Er 3+ /Ho 3+ co-doped barium gallo-germanate glasses is a potential material for 2.0 μm fiber laser.

Elemental bismuth (Bi) exhibits a high magnetoresistance as a typical example of semimetal, which has significant application in information technologies. Silicate glass-clad Bi core fibers were fabricated by a molten core method and maintained core diameter of 100–150 µm and overall diameter of 300–450 µm. X-ray diffraction (XRD) and micro-Raman spectra showed the core to be highly crystalline with no observed secondary phases. Electro-probe micro-analyzer (EPMA) measurements confirmed a very well-defined core-clad interface. Demonstration of fibers with high magnetoresistance core materials and the potential integration with current state of the art technologies represents the first step in providing the building blocks for all-fiber sensors.

In this work, we successfully synthesized heterostructured ZnO-SnO2 composite nanotubes for high performance glycol gas sensor combined with certain calcination treatment. The as-prepared sample was characterized by various technologies. The sensor based on this hybrid nanotube displayed high response (47.71) toward 150 ppm glycol at 210 °C with response/recovery time of approximately 55 and 13 s respectively, even to 5 ppm glycol with a response of about 2.16. It also showed excellent repeatability and long-term stability. These good sensing properties are mainly attributed to the ZnO-SnO2 hollow heterostructure which possesses a large surface area and porosity. Besides, the sensing mechanism was elaborated at length.

In this study, perovskite samarium ferrite (SmFeO3) nanofibers have been successfully fabricated by electrospinning route and calcination process. The as-prepared sample was characterized by various technologies. The results show that the surfaces of SmFeO3 nanofibers are of extreme depression and roughness, which increases contact area between gases and material surface, contributing to enhancing gas sensing properties. The sensor based on as-prepared SmFeO3 nanofibers owns good response and distinct selectivity to ethylene glycol, and response value reaches 18.19 to 100 ppm ethylene glycol at 240 °C, even to 5 ppm ethylene glycol with high response value of 2.18. In addition, the gas sensing mechanism based on hole accumulation layer model was explained in detail.

In this work, we studied Pr doped BiFeO3 hollow nanofibers as a potential functional material, assembled from nanoparticles through electrospinning technique and calcination route, which were decorated by Pr ions and ameliorated by hollow nanofiber structure. The Pr doped BiFeO3 hollow nanofibers, improved by the uniform and tubular structure with a larger specific surface area (63.53 m2/g), higher pore size (38.17 nm) and smaller grain size, revealed better response to formaldehyde (50 ppm, 190 °C, Rgas/Rair = 17.6) along with long-term stability. Moreover, the influence of the relative humidity in atmosphere on the gas performance of the as-prepared sensors was also investigated.