Solar-blind ultraviolet photodetector based on Nb2C/ß-Ga2O3heterojunction.

ß-Ga2O3has been widely investigated for its stability and thermochemical properties. However, the preparation ofß-Ga2O3thin films requires complex growth techniques and high growth temperatures, and this has hindered the application ofß-Ga2O3thin films. In this study,ß-Ga2O3thin films with good crystalline quality were prepared using a green method, and an ultraviolet (UV) detector based onß-Ga2O3with a photocurrent of 2.54 × 10-6A and a dark current of 1.19 × 10-8A has been developed. Two-dimensional materials have become premium materials for applications in optoelectronic devices due to their high conductivity. Here, we use the suitable energy band structure between Nb2C and Ga2O3to create a high carrier migration barrier, which reduces the dark current of the device by an order of magnitude. In addition, the device exhibits solar-blind detection, high responsiveness (28 A W-1) and good stability. Thus, the Nb2C/ß-Ga2O3heterojunction is expected to be one of the promising devices in the field of UV photoelectric detection.

Ultrasonography in Children With Congenital Pyriform Sinus Fistula: Analysis of 31 Cases.

OBJECTIVES: Congenital pyriform sinus fistula (CPSF) is a rare disease that can be easily misdiagnosed. This study investigates the value of ultrasonography in the early diagnosis and treatment of CPSF in children. METHODS: Clinical features and ultrasonography images of 31 CPSF pediatric patients confirmed by operation were retrospectively analyzed, different sonographic features during the infection period and the quiescence period were summarized and the consistency test of ultrasonic recognition and diagnosis between observers was conducted. RESULTS: In this study, 25 CPSF children had thick-walled cystic masses during the infection period, and cystic masses of 8 cases showed gas echo inside; after the modified valsalva maneuver, gas echo was found in another 5 cases. The detection rate of gas can be enhanced through the modified valsalva maneuver and infants' cry so as to provide an important basis for the diagnosis of pyriform sinus fistula. During the quiescent period of inflammation of 6 cases, fistula can be completely shown, and the wall structure has not been completely destroyed, so that the running position of fistula can be clearly seen. Ultrasonography boasted a good inter-observer consistency in identification and determination (Kappa:0.799-0.857; P<0.001). CONCLUSION: Ultrasonography could clearly reveal the position and direction of CPSF fistula. Different ultrasonic characteristics in different periods could provide relevant information for the selection of clinical operation timing and evaluate the post-operative effects.

Sol-Gel Synthesized Amorphous (InxGa1-x)2O3 for UV Photodetection with High Responsivity.

ß-Ga2O3 photodetectors have the advantages of low dark current and strong radiation resistance in UV detection. However, the limited photocurrent has restricted their applications. Herein, MSM UV photodetectors based on (InxGa1-x)2O3 (x = 0, 0.1, 0.2, 0.3) by a sol-gel method were fabricated and studied. The doping of indium ions in Ga2O3 leads to lattice distortion and promotes the formation of oxygen vacancies. The oxygen vacancies in (InxGa1-x)2O3 can be modulated by various proportions of indium, and the increased oxygen vacancies contribute to the enhancement of electron concentration. The results show that the amorphous In0.4Ga1.6O3 photodetector exhibited improved performances, including a high light-to-dark current ratio (2.8 × 103) and high responsivity (739.2 A/W). This work provides a promising semiconductor material In0.4Ga1.6O3 for high-performance MSM UV photodetectors.

A High-Performance UVA Photodetector Based on Polycrystalline Perovskite MAPbCl3/TiO2 Nanorods Heterojunctions.

The application of TiO2 nanorods in the field of ultraviolet (UV) photodetectors is hindered by a high dark current, which is attributed to crystal surface defects and intrinsic excitation by carrier thermal diffusion. Here, a photodetector based on polycrystalline perovskite MAPbCl3/TiO2 nanorods heterojunctions has been fabricated to overcome the shortcoming. The structure was composed of horizontal MAPbCl3 polycrystalline and vertically aligned TiO2 nanorods array. Many localized depletion regions at the MAPbCl3/TiO2 interface can reduce the dark current. The TiO2/MAPbCl3 detector shows high performance including a high ratio of light-dark current of about six orders of magnitude, which is much larger than that of the TiO2 detector. This study indicates the potential in the TiO2/MAPbCl3 heterojunction to fabricate high-performance UV detectors.

Highly Sensitive, Fast Response Perovskite Photodetectors Demonstrated in Weak Light Detection Circuit and Visible Light Communication System.

Organic-inorganic hybrid perovskite (OIHP) photodetectors have presented unprecedented device performance mainly owing to outstanding material properties. However, the solution-processed OIHP polycrystalline thin films with defective surface and grain boundaries always impair the key parameter of photodetectors. Herein, a nonfullerene passivation layer exhibits more efficient passivation for OIHP materials to dramatically reduce the trap density of state, yielding a dark current as low as 2.6 × 10-8 A cm-2 under -0.1 V. In addition, the strong absorption in near-infrared (NIR) region of nonfullerene/C60 heterojunction broadens the detectable range to over 900 nm by effective charge transport, ultimately leading to a specific detectivity of 1.45 × 1012 and 7.37 × 1011 cm Hz1/2 W-1 at 650 and 820 nm, respectively. Encouragingly, the response speed of 27 ns is obtained at 0.6 mm2 of device area by removing constrain from the resistance-capacitance constant. Moreover, the prominent practical application of the photodetector is demonstrated in a weak light detection circuit and a visible light communication system. It is believed that the OIHP photodetectors with high sensitivity, NIR photoresponse, and ultrafast speed would pave the way to commercial applications.

UV detector based on an FTO/TiO2/MoO3 heterojunction with a potential well trapping electrons in the dark.

An FTO/TiO2/MoO3 based UV detector has been fabricated through the synthesis of TiO2 nanowires (NWs) on FTO using the hydrothermal method, the preparation of MoO3 on TiO2 NWs by the spin-coating method, after the hydrothermal synthesis, and the preparation of Ag electrodes on the FTO and MoO3. The detector exhibits an excellent performance of photo-to-dark current ratio of more than two orders of magnitude. This performance is produced because the dark current under 2.2 V bias has been significantly inhibited due to the electronic potential well formed by the energy band distribution while the photocurrent has increased in comparison with FTO/TiO2 based detectors under the same conditions which also have a higher photo-to-dark current ratio without the MoO3 content. Not only does this study take advantage of 1D NWs and 2D nanostructures, but it also provides a new way to inhibit the dark current of detectors.

Built-in electric field promotes photoexcitation separation and depletion of most carriers in TiO2:C UV detectors.

TiO2 has been widely used in ultraviolet (UV) photodetectors, but due to the large number of structural defects and strong band-to-band recombination of the exciton in TiO2, the devices usually have large dark current (I d) and low light current (I l), which seriously reduces the sensitivity and responsivity (R) of the TiO2 based devices. In this work, carbon (C) quantum dots (QDs) are introduced into TiO2 film to ameliorate these issues. Due to the difference of work function between TiO2 nanoparticles and C QDs, the built-in electric field (E bi) can be formed, which effectively facilitates the photogenerated exciton dissociation in the TiO2 film under UV illumination. Meanwhile, the constructed depletion region in dark reduces the majority carrier density, thus decreasing the I d of the photodetector. Moreover, the E bi and depletion region will also contribute to the faster charge collection under UV illumination and recombination of the electron in dark, which is beneficial for the improved response/recovery speed of the device.

A PFTBT modified visible-blind ultraviolet photodetector with a narrow detecting range and high responsivity.

A visible-blind ultraviolet (UV) photodetector (PD) based on TiO2/polyvinyl carbazole doped with poly {[2,7-(9-(20-ethylhexyl)-9-hexyl-fluorene])-alt-[5,50-(40,70-di-2-thienyl-20,10,30-benzothid-iazole)]} (PFTBT) was successfully fabricated. The introduced PFTBT exhibits high absorbance in the UV region and high conductivity which increases the device absorbance and the efficiency of carrier mobility. Besides, PFTBT acts as traps which can increase the concentration of the majority carrier. Therefore, the doped device exhibits high responsivity and high specific detectivity with the value of 0.22 A W-1 and 1.78 × 1012 Jones which respectively has a 3.6 and 2.6 times greater enhancement than the device without doping. The response time is also improved from 27 ms to 22 ms. Owing to the different absorbances that the materials have, the PD has a narrow detection range from 320 nm to 340 nm which is helpful to the study of the specific wavelength. In other words, the research provides a potential way to fabricate practical high-performance UVPDs.

Hematopoietic progenitor cell lines with myeloid and lymphoid potential.

Investigation of immune-cell differentiation and function is limited by shortcomings of suitable and scalable experimental systems. Here we show that retroviral delivery of an estrogen-regulated form of Hoxb8 into mouse bone marrow cells can be used along with Flt3 ligand to conditionally immortalize early hematopoietic progenitor cells (Hoxb8-FL cells). Hoxb8-FL cells have lost self-renewal capacity and potential to differentiate into megakaryocytes and erythrocytes but retain the potential to differentiate into myeloid and lymphoid cells. They differentiate in vitro and in vivo into macrophages, granulocytes, dendritic cells, B lymphocytes and T lymphocytes that are phenotypically and functionally indistinguishable from their primary counterparts. Quantitative in vitro assays indicate that myeloid and B-cell potential of Hoxb8-FL cells is comparable to that of primary lymphoid-primed multipotent progenitors, whereas T-cell potential is diminished. The simplicity of this system and the unlimited proliferative capacity of Hoxb8-FL cells will enable studies of immune-cell differentiation and function.

Association between Gamma-Glutamyltransferase Level and Risk of Stroke: A Systematic Review and Meta-analysis of Prospective Studies.

BACKGROUND: Stroke is often regulated by a number of modifiable and nonmodifiable risk factors. Recently, studies suggested high gamma-glutamyltransferase (GGT) level may be associated with stroke, but drew inconsistent conclusions. So, we conducted a meta-analysis to evaluate the relationship between GGT level and risk of stroke. METHODS: We systematically searched PubMed, Embase, and Cochrane Library (updated to January 2015) for prospective cohort studies. Then, relative risk (RR) with 95% confidence interval (CI) was used to assess the association. Regression analyses, subgroup analyses, and sensitivity analyses were also performed. The Begg test, Egger test, and the trim-and-fill method were used to assess potential publication bias. RESULTS: A total of 5707 cases and 926,497 participants in 10 prospective studies were included. Overall, high GGT level has a positive association with increased risk of stroke (RR = 1.28; 95% CI, 1.16-1.43). In the subgroup analyses, a positive association was consistently observed in each subgroup except in the women subgroup (RR = 1.45; 95% CI, .9-2.34) and a large number of stroke events subgroups (≥ 500) (RR = 1.25; 95% CI, .85-1.84). Heterogeneity was significantly reduced in the subgroup analysis by population characteristics. In the publication bias test, the resulting adjusted RR remained significant (RR = 1.10; 95% CI, 1.00-1.21) after using the trim-and-fill method. CONCLUSIONS: Our meta-analysis provides evidence that a high level of GGT is significantly associated with increased risk of stroke independently of alcohol intake. Gender and ethnicity variations may exist in the relationship between high GGT level and risk of stroke.

Photovoltaic properties of Zr(x)Ti(1-x)O2 solid solution nanowire arrays.

In this paper, Zr(0.05Ti(0.95)O2 solid solution nanowire arrays (NWs) were prepared by a low temperature hydrothermal method. The as-prepared NWs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-visible (UV-vis) spectroscopy. With the doping of Zr content, the band gap of the composite can be varied in a wide range and excellent photoelectric properties of the arrays could be obtained. Moreover, a preliminary study on the photoelectric properties was conducted, which indicates potential applications of the arrays for fabricating high performance ultraviolet photodetectors.

Solar-blind photodetector based on LaAlO3 with low dark current.

In this letter, metal-semiconductor-metal (MSM) solar-blind photodetector was fabricated on LaAlO3 (110) substrates with Pt and Au electrodes. The substrate material was characterized by XRD and UV-visible absorption spectrum. At 10 V bias, the photodetector with Pt electrodes shows a very low dark current of 4.1 pA, which is much smaller than that of detector with Au electrodes (14.6 pA). The low dark current may be attributed to the high density steps and facets on the (110) surface as well as the large lattice mismatch at the Pt/LaAlO3 interface. The device exhibits a peak responsivity of 32.5 mA/W at 200 nm ultraviolet light, which lies in the solar-blind spectral region (200-280 nm). The reasons of low dark current and high responsivity, which were important to photodetectors, were discussed in detail.

A20-binding inhibitor of NF-κB (ABIN1) controls Toll-like receptor-mediated CCAAT/enhancer-binding protein ß activation and protects from inflammatory disease.

Toll-like receptors (TLRs) are expressed on innate immune cells and trigger inflammation upon detection of pathogens and host tissue injury. TLR-mediated proinflammatory-signaling pathways are counteracted by partially characterized anti-inflammatory mechanisms that prevent exaggerated inflammation and host tissue damage as manifested in inflammatory diseases. We biochemically identified a component of TLR-signaling pathways, A20-binding inhibitor of NF-κB (ABIN1), which recently has been linked by genome-wide association studies to the inflammatory diseases systemic lupus erythematosus and psoriasis. We generated ABIN1-deficient mice to study the function of ABIN1 in vivo and during TLR activation. Here we show that ABIN1-deficient mice develop a progressive, lupus-like inflammatory disease characterized by expansion of myeloid cells, leukocyte infiltrations in different parenchymatous organs, activated T and B lymphocytes, elevated serum Ig levels, and the appearance of autoreactive antibodies. Kidneys develop glomerulonephritis and proteinuria, reflecting tissue injury. Surprisingly, ABIN1-deficient macrophages exhibit normal regulation of major proinflammatory signaling pathways and mediators but show selective deregulation of the transcription factor CCAAT/enhancer binding protein ß (C/EBPß) and its target genes, such as colony-stimulating factor 3 (Csf3), nitric oxide synthase, inducible (Nos2), and S100 calcium-binding protein A8 (S100a8). Their gene products, which are intimately linked to innate immune cell expansion (granulocyte colony-stimulating factor), cytotoxicity (inducible nitric oxide synthase), and host factor-derived inflammation (S100A8), may explain, at least in part, the inflammatory phenotype observed. Together, our data reveal ABIN1 as an essential anti-inflammatory component of TLR-signaling pathways that controls C/EBPß activity.

Photovoltaic ultraviolet detectors based on Zr(0.04)Ti(0.96)O2 solid solution nanowire arrays.

A Zr(0.04)Ti(0.96)O(2) solid solution nanowire (NW) array was prepared and characterized in detail. Zr doping effectively changed Zr(x)Ti(1-x)O(2)'s bandgap and led to better photoelectric properties, which indicated the possibility for deep UV detector fabrication. Based on the NW array, high-performance Schottky diode UV detector with Ag electrode was fabricated. At -3 V bias, the dark current of the detector is only 5 nA, and a high photoresponse of 5.6 A/W was achieved because of the internal gain. The ratio of photocurrent to dark current is more than three orders of magnitude. The device is promising for large-area UV detector applications.

Prediction of Prognosis of Tongue Squamous Cell Carcinoma Based on Clinical MR Imaging Data Modeling.

Objective: Tongue squamous cell carcinoma (TSCC) is one of the most common and poor prognosis head and neck tumors. The purpose of this study is to establish a model for predicting TSCC prognosis based on clinical and MR radiomics data and to develop a nomogram. Methods: A retrospective analysis was performed on the clinical and imaging data of 211 patients with pathologically confirmed TSCC who underwent radical surgery at xx hospital from February 2011 to January 2020. Patients were divided into a study group (recurrence, metastasis, and death, n = 76) and a control group (normal survival, n = 135) according to 1 to 6 years of follow-up. A training set and a test set were established based on a ratio of 7:3 and a time point. In the training set, 3 prediction models (clinical data model, imaging model, and combined model) were established based on the MR radiomics score (Radscore) combined with clinical features. The predictive performance of these models was compared using the Delong curve, and the clinical net benefit of the model was tested using the decision curve. Then, the external validation of the model was performed in the test set, and a nomogram for predicting TSCC prognosis was developed. Results: Univariate analysis confirmed that betel nut consumption, spicy hot pot or pickled food, unclean oral sex, drug use, platelet/lymphocyte ratio (PLR), neutrophil/lymphocyte ratio (NLR), depth of invasion (DOI), low differentiation, clinical stage, and Radscore were factors that affected TSCC prognosis (P < .05). In the test set, the combined model based on these factors had the highest predictive performance for TSCC prognosis (area under curve (AUC) AUC: 0.870, 95% CI [0.761-0.942]), which was significantly higher than the clinical model (AUC: 0.730, 95% CI [0.602-0.835], P = .033) and imaging model (AUC: 0.765, 95% CI [0.640-0.863], P = .074). The decision curve also confirmed the higher clinical net benefit of the combined model, and these results were validated in the test set. The nomogram developed based on the combined model received good evaluation in clinical application. Conclusion: MR-LASSO extracted texture parameters can help improve the performance of TSCC prognosis models. The combined model and nomogram provide support for postoperative clinical treatment management of TSCC.

Ultraviolet photodetector with high internal gain enhanced by TiO2/SrTiO3 heterojunction.

In this letter, TiO2 nanocrystalline film was prepared on SrTiO3 (001) substrate to form an n-n heterojunction active layer. Interdigitated Au electrodes were deposited on the top of TiO2 film to fabricate modified HMSM (heterojunction metal-semiconductor-metal) ultraviolet photodetector. At 10 V bias, the dark current of the detector was only 0.2 nA and the responsivity was 46.1 A/W at 260 nm. The rise and fall times of the device were 3.5 ms and 1.4 s, respectively. The TiO2/SrTiO3 heterojunction contributed a lot to the high responsivity and reduced the fall time, which improved the device performance effectively. These results demonstrate the excellent application of TiO2/SrTiO3 heterojunction in fabricating high performance UV photodetectors.

Schottky barrier characteristics and internal gain mechanism of TiO2 UV detectors.

High-responsivity metal-semiconductor-metal TiO(2) UV photodetectors with Ni and Au electrodes were fabricated identically. Their Schottky barrier heights and photocurrent gain mechanism were studied. The effective barrier height Φ and ideality factor n were evaluated according to the thermionic emission theory. The result that Φ(Ni) was lower than Φ(Au) may be attributed to the electron transfer from Ni to the TiO(2) substrate, which would lead to a dipole layer and, accordingly, decrease the barrier height. In addition, the I-V characteristics of the Ni/TiO(2)/Ni and Au/TiO(2)/Au photodetectors were observed. A significant internal gain was obtained, and the mechanism of the internal gain was studied by the phototransistor model in detail.

The GTPase Rab3b/3c-positive recycling vesicles are involved in cross-presentation in dendritic cells.

Antigen cross-presentation in dendritic cells is a complex intracellular membrane transport process, but the underlying molecular mechanisms remain to be thoroughly investigated. In this study, we examined the effect of siRNA-mediated knockdown of 57 Rab GTPases, the key regulators of membrane trafficking, on antigen cross-presentation. Twelve Rab GTPases were identified to be associated with antigen cross-presentation, and Rab3b/3c was indicated to be colocalized with MHC class I molecules at perinuclear tubular structure. Tracing with fluorescence protein-tagged beta(2)-microglobulin demonstrated that the MHC class I molecules were internalized from the plasma membrane to Rab3b/3c-positive compartments, which were also colocalized with the internalized transferrin. Moreover, depletion of Rab3b/3c strongly reduced the fast phase recycling rate of transferrin receptors. Furthermore, the Rab3b/3c-positive compartments were colocalized with a fraction of Rab27a at a juxtaposition of phagosomes. Together, these data demonstrate that Rab3b/3c-positive recycling vesicles are involved in and may constitute one of the recycling compartments in exogenous antigen cross-presentation.

Ultrasonographic analysis of Langerhans cell histiocytosis in children: a report of 55 cases.

OBJECTIVE: To explore the value of ultrasonography in the diagnosis and treatment of Langerhans cell histiocytosis (LCH) in children. METHOD: The clinical and imaging features of 55 children with pathologically confirmed LCH were retrospectively analyzed. RESULTS: Thirteen patients had bone LCH and 42 had multisystem LCH. Among the 13 cases of bone LCH, 8 cases involving the skull and 2 involving the scapula were characterized by osteolytic bone destruction, 1 case involving the clavicle and 1 involving the iliac bone showed multiple irregular bone destruction, and 1 case involving the tibia showed local hypoechoic cortical bone. Soft tissue echo filling was present in the local areas of bone destruction. Among the 42 cases of multisystem LCH, 33 involved the bone, 35 showed an enlarged liver, 15 involved the spleen, 2 involved the pancreas, 3 involved the lung, 3 involved the thymus, and 21 affected the lymph nodes in different regions. CONCLUSIONS: Ultrasonography of the flat bones in children with LCH mainly showed punched-out osteolytic bone destruction. Long bone lesions were characterized by fan shell changes in the endosteum of long bones, and some also showed bone destruction. Multisystem LCH can affect almost any organ. Ultrasonography is important for early diagnosis.

Design of a vector-sum integrated microwave photonic phase shifter in silicon-on-insulator waveguides.

An orthogonal vector-sum integrated microwave photonic phase shifter (IMWPPS), consisting of mode-order converter multiplexers (MOCMs), a variable optical power splitter (VOPS), an optical switch (OS) and fixed time delay lines (FTDLs), was theoretically demonstrated in a silicon-on-insulator wafer. MOCMs, as a key element of our device, were employed to generate orthogonal vector signals and served as lossless optical combiners. Combining with the thermo-optical VOPS, OS and FTDLs, the microwave phase shift of 0∼2π could be achieved by a refractive index variation of 0∼15×10(-3) in the millimeter wave band. The corresponding tuning resolution was about 1.64°/°C. This work, for the first time to our knowledge, provides an attractive solution to transferring a vector-sum method based bulk MWPPS into a integrated one, which is very important for large-scale optically controlled phase array antenna.