We report the quantum transport properties of Cd3As2 single crystals in a magnetic field. A large linear quantum magnetoresistance is observed near room temperature. With decreasing temperature, the ...Shubnikov-de Haas oscillations appear in both the longitudinal resistance Rxx and the transverse Hall resistance Rxy. From the strong oscillatory component Delta Rxx, a linear dependence of the Landau index n on 1/B is obtained, and it gives an n-axis intercept between 1/2 and 5/8. This clearly reveals a nontrivial pi Berry's phase, which is a distinguished feature of Dirac fermions. Our quantum transport results provide bulk evidence for the existence of a three-dimensional Dirac semimetal phase in Cd3As2.
Chidamide is a novel benzamide type of subtype-selective histone deacetylase (HDAC) inhibitor with unique mechanisms of action compared with marketed HDAC inhibitors. This phase II study was to ...evaluate the efficacy and safety of chidamide in relapsed or refractory peripheral T-cell lymphoma (PTCL) in Chinese population.
Patients with relapsed or refractory PTCL of different subtypes received chidamide of 30 mg orally twice per week. The primary end point was overall response rate (ORR). Responding patients should be confirmed at least 4 weeks after the criteria of the response were first met, and were reviewed by an independent review committee.
Eighty-three patients were enrolled and 79 patients with eligible PTCL histology were for efficacy assessments. Patients enrolled over 10% were with subtypes of PTCL not otherwise specified (34%), anaplastic large-cell lymphoma (22%), extranodal natural killer (NK)/T-cell lymphoma, nasal type (20%), or angioimmunoblastic T-cell lymphoma (AITL, 13%). The ORR was 28% (22 of 79) including 14% (11 of 79) with complete response/unconfirmed complete response (CR/CRu). Median progression-free survival and overall survival were 2.1 and 21.4 months, respectively. AITL patients tended to have higher ORR (50%) and CR/CRu rate (40%), as well as more durable responses, to chidamide treatment. Most adverse events (AEs) were grade 1 or 2, and AEs ≥grade 3 that occurred in ≥10% patients were thrombocytopenia (22%), leucopenia (13%) and neutropenia (11%), respectively.
Chidamide represents a novel oral benzamide class of HDAC inhibitor with significant single-agent activity and manageable toxicity in relapsed or refractory PTCL, and provides a much needed treatment option in this indication in China. Results led to China Food and Drug Administration approval of chidamide in this indication.
The realization of optical non-reciprocity is crucial for many applications, and also of fundamental importance for manipulating and protecting the photons with desired time-reversal symmetry. ...Recently, various new mechanisms of magnetic-free non-reciprocity have been proposed and implemented, avoiding the limitation of the strong magnetic field imposed by the Faraday effect. However, due to the difficulties in separating the signal photons from the drive laser and the noise photons induced by the drive laser, these devices exhibit limited isolation performances and their quantum noise properties are rarely studied. Here, we demonstrate an approach of magnetic-free non-reciprocity by optically-induced magnetization in an atom ensemble. Excellent isolation (highest isolation ratio is Formula: see text) is observed over a power dynamic range of 7 orders of magnitude, with the noiseless property verified by quantum statistics measurements. The approach is applicable to other atoms and atom-like emitters, paving the way for future studies of integrated photonic non-reciprocal devices.
Microresonators on a photonic chip could enhance nonlinear optics effects and thus are promising for realizing scalable high-efficiency frequency conversion devices. However, fulfilling phase ...matching conditions among multiple wavelengths remains a significant challenge. Here, we present a feasible scheme for degenerate sum-frequency conversion that only requires the two-mode phase matching condition. When the drive and the signal are both near resonance to the same telecom mode, an on-chip photon-number conversion efficiency up to 42% is achieved, showing a broad tuning bandwidth over 250 GHz. Furthermore, cascaded Pockels and Kerr nonlinear optical effects are observed, enabling the parametric amplification of the optical signal to distinct wavelengths in a single device. The scheme demonstrated in this Letter provides an alternative approach to realizing high-efficiency frequency conversion and is promising for future studies on communications, atom clocks, sensing, and imaging.
Variations in tensile yield strength of annealed CuAl7 copper alloy were investigated. Both grain and feature size effects could be observed. Statistical analysis revealed that the grain size effect ...was greater than the feature size effect. The grain size effect on the tensile yield strength of the alloy was very significant. The feature size effect was very significant or significant when the specimen thickness was no more than 0.50mm, while the effect was insignificant or completely absent when the specimen thickness was greater than 0.50mm. In addition to grain size d and specimen thickness t, the t/d ratio of the specimen can also affect the tensile yield strength. The tensile yield strength of the alloy was almost a constant when the t/d ratio was greater than a critical value (approximately 21). Otherwise, the strength tended to increase with an increasing value of t/d, except for the specimen with a thickness of 0.25mm. The size effects on the tensile strength of the CuAl7 copper alloy were compared with the effects on the compression strength. It was found that the size effect intensity on the compression yield strength was greater than that on the tensile yield strength.
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•Effects of both grain and feature size could be observed on tensile yield strength of the alloy.•The grain size effect was greater than the feature size effect in terms of statistics theory.•Size effect intensity on compression strength was larger than that on tensile strength.•Thickness value of 0.50mm represents a dividing point with respect to the feature size effect.
Non‐reciprocal devices serving as fundamental elements in photonic and microwave circuits have attracted great attention for its applications in both classical and quantum information processing. The ...spin–orbit coupling (SOC) of light in microstructures shows that the polarization affects and controls the spatial degrees of freedom of light, which could been exploited to break the reciprocity of light transmission. Here, non‐reciprocal light transmission is demonstrated experimentally in high‐quality factor yttrium iron garnet microspheres via photonic SOC and Faraday effect. By applying an magnetic field in the vertical direction of resonator equator, the degeneracy of the clockwise and counter‐clockwise whispering gallery modes are lifted. The non‐reciprocal effect is shown for both polarizations and promises applications including non‐reciprocal photonic devices, magneto‐optic modulators, and magnetometers.
The non‐reciprocity of high‐quality factor whispering gallery modes in yttrium iron garnet microspheres has been demonstrated via the photonic spin–orbital coupling. By applying an external bias magnetic field in the vertical direction of the resonator equator, the degeneracy of the clockwise and counter‐clockwise modes is lifted as a result of the Faraday effect. The non‐reciprocal effect is shown for both polarizations.
Nonlinear optical effects in integrated microcavities have been studied extensively with the advantages of strong light-matter interaction, great scalability, and stability due to the small mode ...volume. However, the pump lasers stimulating nonlinear effects impose obstacles for practical applications, since the material absorption causes thermal resonance drift and instability. Here we experimentally demonstrate an all-optical control of the thermal behavior in optical microcavities for tunable doubly-resonant second-harmonic (SH) generation on an integrated photonic chip. Through an auxiliary control laser, the temperature of a selected microring can be efficiently changed, thus allowing precise frequency tuning of the doubly-resonant wavelength while eliminating the distortion of the lineshape induced by the thermo-optic effect. Although the phase-matching conditions will limit the tuning range of 55GHz, the technique is still potential to achieve a larger tuning range in combination with temperature regulation. Additionally, this approach has the advantage of quick reconfiguration, showing a fast modulation rate up to about 256 kHz. The theoretical model behind our experimental scheme is universal and applicable to other microcavity-enhanced nonlinear optical processes, and our work paves the way for controlling and utilizing the thermal effect in the applications of microcavities.
Cell death was examined by studying the spinal cords of rats subjected to traumatic insults of mild to moderate severity. Within minutes after mild weight drop impact (a 10 gm weight falling 6.25 ...mm), neurons in the immediate impact area showed a loss of cytoplasmic Nissl substances. Over the next 7 d, this lesion area expanded and cavitated. Terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL)-positive neurons were noted primarily restricted to the gross lesion area 4-24 hr after injury, with a maximum presence at 8 hr after injury. TUNEL-positive glia were present at all stages studied between 4 hr and 14 d, with a maximum presence within the lesion area 24 hr after injury. However 7 d after injury, a second wave of TUNEL-positive glial cells was noted in the white matter peripheral to the lesion and extending at least several millimeters away from the lesion center. The suggestion of apoptosis was supported by electron microscopy, as well as by nuclear staining with Hoechst 33342 dye, and by examination of DNA prepared from the lesion site. Furthermore, repeated intraperitoneal injections of cycloheximide, beginning immediately after a 12.5 mm weight drop insult, produced a substantial reduction in histological evidence of cord damage and in motor dysfunction assessed 4 weeks later. Present data support the hypothesis that apoptosis dependent on active protein synthesis contributes to the neuronal and glial cell death, as well as to the neurological dysfunction, induced by mild-to-moderate severity traumatic insults to the rat spinal cord.
Chemical insecticides targeting the digestive system of diamondback moth (DBM), Plutella xylostella, have not been developed. The discovery of an insecticide with novel mode of action is a challenge ...for the control of DBM. In this study, a class of selenium- and difluoromethyl-modified azoles (fluoroazole selenoureas, FASU) were designed and synthesized for the control of DBM. Of these azoles, compound B4 showed the highest insecticidal activity against DBM. The LC50 of third- and second-instar larvae reached 32.3 and 4.6 μg mL–1, respectively. The midgut tissue of larvae was severely disrupted, and the larval intestinal tissue was dotted with unique red spots after treatment with compound B4. Compound B4 led to disintegration of the peritrophic matrix, swelling of the midgut epithelium, fracture of the microvilli, and extensive leakage of cellular debris in the midgut lumen. Surviving larvae grew very slowly, and the larval duration was significantly prolonged after exposure to compound B4 at sublethal doses (LC10, LC25 and LC50). Furthermore, the pupation rate, emergence rate and pupae weight were significantly decreased. Compound B4 also induced abnormal pupae, causing adults to be trapped in the cocoon or failure to fly due to twisted wings. These results demonstrated that FASU could reduce the population of DBM in sublethal doses. FASU is the first synthetic insecticidal lead compound that has been shown to disrupt the midgut tissue of the larvae of DBM, and its mode of action totally differs from that of commercial chemical insecticides.
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