Dual color infrared photodetector with superconducting metamaterials.

Superconducting photodetection offers a wide spectral coverage ranging from the microwave to X-ray, and in the short wavelength range, single photon sensitivity can be achieved. However, in the longer wavelength infrared region, the system detection efficiency is low due to the lower internal quantum efficiency and weak optical absorption. Here, we utilized the superconducting metamatieral to enhance the light coupling efficiency and reach nearly perfect absorption at dual color infrared wavelengths. Dual color resonances arise from hybridization of local surface plasmon mode of the metamaterial structure and the Fabry-Perot-like cavity mode of metal (Nb)-dielectric (Si)-metamatieral (NbN) tri-layer structure. We demonstrated that, at the working temperature of 8 K slightly below TC ∼8.8 K, this infrared detector exhibits the peak responsivity of 1.2 × 106V/W and 3.2 × 106V/W at two resonant frequencies 36.6 THz and 104 THz, respectively. The peak responsivity is enhanced about ∼8 and ∼22 times, respectively, compared to that of non-resonant frequency (67 THz). Our work provides a way to harvest infrared light efficiently and hence improve the sensitivity of superconducting photodetectors in multispectral infrared range, which may find promising applications in thermal image and gas sensing etc.

Approaching a Minimal Topological Electronic Structure in Antiferromagnetic Topological Insulator MnBi2Te4 via Surface Modification.

The topological electronic structure plays a central role in the nontrivial physical properties in topological quantum materials. A minimal, "hydrogen-atom-like" topological electronic structure is desired for research. In this work, we demonstrate an effort toward the realization of such a system in the intrinsic magnetic topological insulator MnBi2Te4, by manipulating the topological surface state (TSS) via surface modification. Using high resolution laser- and synchrotron-based angle-resolved photoemission spectroscopy (ARPES), we found the TSS in MnBi2Te4 is heavily hybridized with a trivial Rashba-type surface state (RSS), which could be efficiently removed by the in situ surface potassium (K) dosing. By employing multiple experimental methods to characterize K dosed surface, we attribute such a modification to the electrochemical reactions of K clusters on the surface. Our work not only gives a clear band assignment in MnBi2Te4 but also provides possible new routes in accentuating the topological behavior in the magnetic topological quantum materials.

The proliferation and differentiation of spermatogonial stem cells in the frist wave of spermatogenesis in rats with Trib3 gene knockout.

This study explores the effects of Trib3 gene knockout on adult male rat spermatogenesis. Using CRISPR/Cas9, we knocked out the Trib3 gene in Wistar rats. Results indicate altered expression of PLZF, ID4, and c-KIT in knockout rats, suggesting impaired spermatogonial stem cell proliferation and differentiation. Histological analysis reveals reduced seminiferous tubule area and decreased spermatocyte numbers. Mating experiments demonstrate reduced offspring rates after the second self-mating in knockout rats. SYCP3, a meiosis marker, shows elevated expression in knockout rat testes at 14 days postpartum, suggesting an impact on reproductive processes. ELISA results indicate decreased testosterone, FSH, and FGF9 levels in knockout rat testicular tissues. In conclusion, Trib3 gene deletion may impede spermatogonial self-renewal and promote differentiation through the FSH-FGF9- c-KIT interaction and p38MAPK pathway, affecting reproductive capacity. These findings contribute to understanding the molecular mechanisms regulating spermatogenesis.

Shape-Tunable 4D Printing of LCEs via Cooling Rate Modulation: Stimulus-Free Locking of Actuated State at Room Temperature.

Liquid crystal elastomers (LCEs) have garnered considerable attention in the field of four-dimensional (4D) printing due to their large, reversible, and anisotropic shape-morphing capabilities. By utilizing direct ink writing, intricate LCE structures with programmable shape morphing can be achieved. However, the maintenance of the actuated state for LCEs requires continuous and substantial external stimuli, presenting challenges for practical applications, particularly under ambient conditions. This study reports a straightforward and effective physical approach to lock the actuated state of LCEs through rapid cooling while preserving their reversible performance. Rapid cooling significantly reduces the mobility of the lightly cross-linked network in LCEs, resulting in a notably slow recovery of mesogen alignment. As a result, the locked LCE structures retain their actuated state even at room temperature. Moreover, we demonstrate the ability to achieve tunable shapes between the original and actuated states by modulating the cooling rate, i.e., varying the temperature and type of cooling medium. The proposed method opens up new possibilities to achieve stable and tunable shape locking of soft devices for engineering applications.

Endostatin attenuates heart failure via inhibiting reactive oxygen species in myocardial infarction rats.

The purpose of the present study was to evaluate whether endostatin overexpression could improve cardiac function, hemodynamics, and fibrosis in heart failure (HF) via inhibiting reactive oxygen species (ROS). The HF models were established by inducing ischemia myocardial infarction (MI) through ligation of the left anterior descending (LAD) artery in Sprague-Dawley (SD) rats. Endostatin level in serum was increased in MI rats. The decrease in cardiac function and hemodynamics in MI rats were enhanced by endostatin overexpression. Endostatin overexpression inhibited the increase in collagen I, collagen III, α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), matrix metalloproteinase (MMP)-2 and MMP9 in the hearts of MI rats. MI-induced cardiac hypertrophy was reduced by endostatin overexpression. The increased levels of malondialdehyde (MDA), superoxide anions, the promoted NAD(P)H oxidase (Nox) activity, and the reduced superoxide dismutase (SOD) activity in MI rats were reversed by endostatin overexpression. Nox4 overexpression inhibited the cardiac protective effects of endostatin. These results demonstrated that endostatin improved cardiac dysfunction and hemodynamics, and attenuated cardiac fibrosis and hypertrophy via inhibiting oxidative stress in MI-induced HF rats.

[Functional significance of TGF-beta1 signal transduction pathway in oral squamous cell carcinoma].

OBJECTIVE: The aim of this study was to investigate the expression of transforming growth factor-beta1 (TGF-beta1) and its signaling pathway molecules in oral squamous cell carcinoma (OSCC) and analyze the association between these factors and genesis and metastasis of OSCC. METHODS: The express of TGF-beta1, TbetaRI, TbetaRII and Smad4, a pivotal downstream molecule of its signaling, in 10 normal oral mucosa tissues and 108 OSCC was detected by SP immunohistochemistry, and thier correlation with genesis and metastasis of OSCC were assessed. RESULTS: The expressions of TbetaRII and Smad4 were lower in the tumors (34.3%, 38.9%) than those in the normal oral epithelium (80.0%, 100.0%, P < 0.05). The positive expression rates of TGF-beta1 and TbetaRI in the normal oral epithelium and OSCC were not significantly different (P > 0.05). There was an inverse correlation between TGF-beta1, Smad4, TbetaRII, TbetaRI expression and clinical stages (P < 0.01). The expression of TGF-beta1 was related with histological differentiation and tumor localization (P < 0.05). There was a relationship beteween Smad4 expression and histological differentiation and lymph node metastasis (P < 0.05). The expression of TbetaRII in the samples with lymph node metastasis was less than that in the ones without lymph node metastasis (P < 0.01), although there was no association between expression of TbetaRII and lymph node metastasis status. CONCLUSION: There is an important relationship between the abnormal TGF-beta1/Smad4 signal pathway and genesis and development of OSCC, while the low expressed Smad4 and TbetaRII may promote the metastasis of OSCC.

Multiple gaps revealed by low temperature specific heat in the 1111-type CaFe0.88Co0.12AsF single crystals.

Low-temperature specific heat (SH) is measured on the 1111-type CaFe0.88 Co0.12AsF single crystals under different magnetic fields. A clear SH jump with the height [Formula: see text] mJ mol-1 K-2 is observed at the superconducting transition temperature T c . The electronic SH coefficient [Formula: see text] increases linearly with the field below 5 T and a kink is observed around 5 T, indicating a multi-gap feature in the present system. Such a sign is also reflected in the T c - B data. A detailed analysis shows that this behavior can be interpreted in terms of a two-gap scenario with the ratio [Formula: see text]-4.5.

Structure and properties of type-II clathrate Cs8Na16-xTlxGe136.

Tl-doped type-II clathrate Cs8Na16-xTlxGe136 was synthesized from its elements. The structure was characterised by single crystal and powder diffraction. Cs8Na16-xTlxGe136 crystallized in the space group Fd3[combining macron]m. The melting point decreased with increasing Tl content at 925.0 °C, 922.8 °C and 915.7 °C for Cs8Na14.76(3)Tl1.24(2)Ge136, Cs8Na9.94(2)Tl6.06(2)Ge136 and Cs8Na8.36(2)Tl7.64(2)Ge136 in Ar atmosphere, respectively. Cs8Na9.94(2)Tl6.06(2)Ge136 exhibited diamagnetism with χ = -3.11 × 10(-3) emu mol(-1) at 1.8 K. The heat capacity of Cs8Na9.94(2)Tl6.06(2)Ge136 presented an Einstein peak at 10 K. The fitted parameters for Cs8Na9.94(2)Tl6.06(2)Ge136 were λ = 0.115(4) J mol(-1) K(-2), ß = 0.0289(2) J mol(-1) K(-4), NE = 7.94(4), θE = 56.9(1) K, ND = 152.06(4) and θD = 217(1) K using the equation Cp = Ce + CD + CE from 1.8 K to 10 K. The thermoelectric measurement showed metallic resistivity and a negative Seebeck coefficient, indicating electron-type charge carriers. The electronic structure calculation for Cs8Na10Tl6Ge136 confirmed the nature of the metallic transport behavior with conducting electrons, mainly from the Ge p orbitals.

Raman enhancement by graphene-Ga2O3 2D bilayer film.

2D ß-Ga2O3 flakes on a continuous 2D graphene film were prepared by a one-step chemical vapor deposition on liquid gallium surface. The composite was characterized by optical microscopy, scanning electron microscopy, Raman spectroscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy (XPS). The experimental results indicate that Ga2O3 flakes grew on the surface of graphene film during the cooling process. In particular, tenfold enhancement of graphene Raman scattering signal was detected on Ga2O3 flakes, and XPS indicates the C-O bonding between graphene and Ga2O3. The mechanism of Raman enhancement was discussed. The 2D Ga2O3-2D graphene structure may possess potential applications.

[Inhibitory effect of transforming growth factor-ß(1) on oral squamous cell carcinoma brain metastasis Tb cell line].

OBJECTIVE: To investigate the inhibitory effect of transforming growth factor (TGF)-ß1 on oral squamous cell carcinoma (OSCC) Tb cell line. METHODS: Cell counting method was used to examine the inhibitory effect of TGF-ß1 on Tb cell and flow cytometry (FCM) assay performed to measure the changes of cell cycle. Superarray was used to screen the changing expression of genes in TGF-ß1/Smads signaling pathway.RT-PCR method was used to detect the results of Superarray. RESULTS: TGF-ß1 showed significant inhibiting effect on OSCC Tb cell line. TGF-ß1 blocked the cell cycle at G1 phase. The expression level of activin receptor-like kinase-1 (ACVRL-1), anti-mullerian hirmine (AMH), cyclim-dependent kinase inhibitor-2B (CDKN-2B) and transforming growth factor-beta-indnced factor (TGIF) was higer in the cells treated with TGF-ß1 than in control, while TDGF-1 expression was down-regulated. ACVRL-1 and CDKN-2B gene expression was consistent with the results of Superarray. CONCLUSIONS: TGF-ß1 can inhibit the growth of OSCC Tb cell line. The mechanism may be related to the regulation of cell cycle and the expression of ACVRL-1 and CDKN-2B in TGF-ß1-Smads signaling pathway.

[Role of Survivin gene on the apoptosis of adenoid cystic carcinoma-2 cells induced by arsenic trioxide].

OBJECTIVE: To investigate the proliferation effects of arsenic trioxide (As2O3) on salivary adenoid cystic carcinoma-2 (ACC-2) cells in vitro and to study the role of Survivin on the apoptosis of ACC-2 induced by As2O3. METHODS: ACC-2 cells were treated with different concentration of As2O3 for different time. The inhibitory effects on cell's viability were assayed with methyl thiazolyl tetrazolium (MTT) test. Apoptosis was determined by flow cytometry. The expression of Survivin mRNA and protein were investigated by reverse transcription-polymerase chain raction (RT-PCR) and Western blot analysis respectively. RESULTS: Cell viability after As2O3 treatment was markedly suppressed and exhibited as a dose- and time-dependent pattern. The apoptotic index showed the similar trend. The results of RT-PCR revealed gene expression of Survivin was suppressed significantly. Through Western blot analysis, a negative correlation between concentration and amount of protein product of Survivin was determined. CONCLUSION: As2O3 might markedly suppressed ACC-2 cell's viability in vitro. The inhibition of Survivin gene expression may play a critical role on ACC-2 cell apoptosis induced by As2O3.