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With global climate change and accelerating urbanization, marine cities face unique environmental challenges. Ecological landscape creation is a form of design planning guided by the disciplines of landscape ecology and ecological aesthetics in the process of urban planning and construction. It seeks a design that can maintain the virtuous cycle of the ecosystem and at the same time maintain the spatial equilibrium of the dynamic development of urban landscapes, so as to make them have good ecological functions and corridor functions. The aim of this study is to explore the ecological design methods of plant landscaping in marine urban green spaces under the concept of sustainability. We first reviewed the concept of sustainable development and its application to urban green space design, especially the special requirements in the marine urban environment. This research focuses on how to select plant species that are adapted to the marine climate and how to promote biodiversity, enhance ecosystem services, and improve the quality of life of urban residents through eco-design approaches. Through the analysis of a number of domestic and international cases of green spaces in marine cities, we found that effective eco-design is not only about choosing the right plant species but also includes the rational management of water resources, soil protection, and ecosystem restoration, among other aspects. This study also points out that public participation and interdisciplinary cooperation play a crucial role in the ecological design process. Finally, this paper carries out a specific analysis of the landscape model landscape evaluation system for the ecological design of plant landscaping in marine urban green spaces and experimentally verifies that, compared with other styles, the experience of the European-style landscape is good overall. However, the view openness rating of the European style landscape is only about 0.42, and the best plant landscaping is the mixed mode of alkali poncho and salt poncho. This study aims to provide a practical reference and guidance for urban planners, landscape architects, and environmentalists.
ABSTRACT
We report a resonant cavity infrared detector (RCID) with an InAsSb/InAs superlattice absorber with a thickness of only ≈ 100â nm, a 33-period GaAs/Al0.92Ga0.08As distributed Bragg reflector bottom mirror, and a Ge/SiO2/Ge top mirror. At a low bias voltage of 150â mV, the external quantum efficiency (EQE) reaches 58% at the resonance wavelength λres ≈ 4.6â µm, with linewidth δλ = 19-27â nm. The thermal background current for a realistic system scenario with f/4 optic that views a 300â K scene is estimated by integrating the photocurrent generated by background spanning the entire mid-IR spectral band (3-5â µm). The resulting specific detectivity is a factor of 3 lower than for a state-of-the-art broadband HgCdTe device at 300â K, where dark current dominates the noise. However, at 125â K where the suppression of background noise becomes critical, the estimated specific detectivity D* of 5.5 × 1012â cm Hz½/W is more than 3× higher. This occurs despite a non-optimal absorber cut-off that causes the EQE to decrease rapidly with decreasing temperature, e.g., to 33% at 125â K. The present RCID's advantage over the broadband device depends critically on its low EQE at non-resonance wavelengths: ≤ 1% in the range 3.9-5.5â µm. Simulations using NRL MULTIBANDS indicate that impact ionization in the bottom contact and absorber layers dominates the dark current at near ambient temperatures. We expect future design modifications to substantially enhance D* throughout the investigated temperature range of 100-300â K.
ABSTRACT
At present, there is a growing focus on the landscape and environment of ocean cities, with an increasing demand for improved ecological sustainability and aesthetic appeal. With the emergence of computer vision design technologies such as 3D and VR, people have overcome the limitations of traditional paper-based design materials. Through the use of computer software, various forms of expression, such as drawings and animations, can be produced, thereby meeting the diverse demands for showcasing plant landscapes. The purpose of this paper is to study the design of marine urban (MU) botanical landscapes based on computer vision technology (CVT) and multimodal interaction design (MID) theory, so that the design of MU botanical landscape can meet people's psychological behavior and visual needs, and at the same time enable people to participate in and experience the landscape, so as to better meet people's needs for viewing, leisure, and entertainment. At the same time, it is hoped that the research of this paper will play a role in promoting the innovation and development of the concept of MU landscape design (LD) in the future, specifically from two levels of theoretical and practical significance. First, at the level of theoretical research: Based on the theory of MID, this paper explores the application of communication and interaction among humans and between humans and the landscape in the design of MU planting, and tries to explore and summarize the content and methods of interactive LD in marine cities with a theoretical basis and research value. The goal is to both enhance the theoretical level of interactive LD, and also provide new reference for future marine city (MC) LD. Second, at the level of practical application: In the field of LD, the new concept of computer vision is introduced to fully understand the visual needs of people and increase the practicality and pleasantness of the MU landscape, hoping to attract more people to come to play and rest. Through the attraction of MU landscapes to tourists, the design and construction of the landscape no longer focus on its appearance, but rather on the participation and experience of people.
ABSTRACT
BACKGROUND/AIMS: We evaluated the feasibility and long-term efficacy of the combination of cytarabine, idarubicin, and all-trans retinoic acid (ATRA) for treating patients with newly diagnosed acute promyelocytic leukemia (APL). METHODS: We included 87 patients with newly diagnosed acute myeloid leukemia and a t(15;17) or promyelocytic leukemia/retinoic acid receptor alpha (PML-RARα) mutation. Patients received 12 mg/m2/day idarubicin intravenously for 3 days and 100 mg/m2/day cytarabine for 7 days, plus 45 mg/m2/day ATRA. Clinical outcomes included complete remission (CR), relapse-free survival (RFS), overall survival (OS), and the secondary malignancy incidence during a 20-year follow-up. RESULTS: The CR, 10-year RFS, and 10-year OS rates were 89.7%, 94.1%, and 73.8%, respectively, for all patients. The 10-year OS rate was 100% for patients that achieved CR. Subjects were classified according to the white blood cell (WBC) count in peripheral blood at diagnosis (low-risk, WBC < 10,000/mm3; high-risk, WBC ≥ 10,000/mm3). The low-risk group had significantly higher RFS and OS rates than the high-risk group, but the outcomes were not superior to the current standard treatment (arsenic trioxide plus ATRA). Toxicities were similar to those observed with anthracycline plus ATRA, and higher than those observed with arsenic trioxide plus ATRA. The secondary malignancy incidence after APL treatment was 2.7%, among the 75 patients that achieved CR, and 5.0% among the 40 patients that survived more than 5 years after the APL diagnosis. CONCLUSION: Adding cytarabine to anthracycline plus ATRA was not inferior to anthracycline plus ATRA alone, but it was not comparable to arsenic trioxide plus ATRA. The probability of secondary malignancy was low.
Subject(s)
Leukemia, Promyelocytic, Acute , Anthracyclines/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Arsenic Trioxide/adverse effects , Cytarabine/adverse effects , Follow-Up Studies , Humans , Idarubicin/adverse effects , Leukemia, Promyelocytic, Acute/diagnosis , Leukemia, Promyelocytic, Acute/drug therapy , Leukemia, Promyelocytic, Acute/genetics , Recurrence , Remission Induction , Treatment Outcome , Tretinoin/adverse effectsABSTRACT
The high-quality growth of midwave infrared light emitters on silicon substrates will advance their incorporation into photonic integrated circuits, and also introduce manufacturing advantages over conventional devices grown on lattice-matched GaSb. Here we report interband cascade light emitting devices (ICLEDs) grown on 4 degree offcut silicon with 12% lattice mismatch. Four wafers produced functioning devices, with variations from wafer to wafer but uniform performance of devices from a given wafer. The full width at half maxima for the (004) GaSb rocking curves were as narrow as â¼ 163 arc seconds, and the root mean square surface roughness as small as 3.2â nm. Devices from the four wafers, as well as from a control structure grown to the same design on GaSb, were mounted epitaxial-side-up (epi-up). While core heating severely limited continuous wave (cw) emission from the control devices at relatively modest currents, efficient heat dissipation via the substrate allowed output from the devices on silicon to increase up to much higher currents. Although the devices on silicon had higher leakage currents, probably occurring primarily at dislocations resulting from the lattice-mismatched growth, accounting for differences in architecture the efficiency at high cw current was approximately 75% of that of our previous best-performing standard epi-down ICLEDs grown on GaSb. At 100â mA injection current, 200-µm-diameter mesas produced 184 µW of cw output power when operated at T = 25 °C, and 140 µW at 85°C. Epi-up mid-IR light emitters grown on silicon will be far simpler to process and much less expensive to manufacture than conventional devices grown on GaSb and mounted epi-down.
ABSTRACT
Midwave infrared interband-cascade light-emitting devices (ICLEDs) have the potential to improve the selectivity, stability, and sensitivity of low-cost gas sensors. We demonstrate a broadband direct absorption CH4 sensor with an ICLED coupled to a plastic hollow-core fiber (1 m length, 1500 µm inner diameter). The sensor achieves a 1σ noise equivalent absorption of approximately 0.2 ppmv CH4 at 1 Hz, while operating at a low drive power of 0.5 mW. A low-cost sub-ppmv CH4 sensor would make monitoring emissions more affordable and more accessible for many relevant industries, such as the petroleum, agriculture, and waste industries.
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We describe how a midwave infrared photonic integrated circuit (PIC) that combines lasers, detectors, passive waveguides, and other optical elements may be constructed on the native GaSb substrate of an interband cascade laser (ICL) structure. The active and passive building blocks may be used, for example, to fabricate an on-chip chemical detection system with a passive sensing waveguide that evanescently couples to an ambient sample gas. A variety of highly compact architectures are described, some of which incorporate both the sensing waveguide and detector into a laser cavity defined by two high-reflectivity cleaved facets. We also describe an edge-emitting laser configuration that optimizes stability by minimizing parasitic feedback from external optical elements, and which can potentially operate with lower drive power than any mid-IR laser now available. While ICL-based PICs processed on GaSb serve to illustrate the various configurations, many of the proposed concepts apply equally to quantum-cascade-laser (QCL)-based PICs processed on InP, and PICs that integrate III-V lasers and detectors on silicon. With mature processing, it should become possible to mass-produce hundreds of individual PICs on the same chip which, when singulated, will realize chemical sensing by an extremely compact and inexpensive package.
ABSTRACT
The interband cascade laser (ICL) is an ideal candidate for low-power mid-infrared frequency comb spectroscopy. In this work, we demonstrate that its intracavity second-order optical nonlinearity induces a coherent up-conversion of the generated mid-infrared light to the near-infrared through second-harmonic and sum-frequency generation. At 1.8 µm, 10 mW of light at 3.6 µm convert into sub-nanowatt levels of optical power, spread across 30 nm of spectral coverage. The observed linear-to-nonlinear conversion efficiency exceeds ${3\;{\unicode{x00B5} {\rm W/W}}^2}$3µW/W2 in continuous wave operation. We use a dual-band ICL frequency comb source to characterize water vapor absorption in both spectral bands.
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The interaction of quantum systems with mechanical resonators is of practical interest for applications in quantum information and sensing and also of fundamental interest as hybrid quantum systems. Achieving a large and tunable interaction strength is of great importance in this field as it enables controlled access to the quantum limit of motion and coherent interactions between different quantum systems. This has been challenging with solid state spins, where typically the coupling is weak and cannot be tuned. Here we use pairs of coupled quantum dots embedded within cantilevers to achieve a high coupling strength of the singlet-triplet spin system to mechanical motion through strain. Two methods of achieving strong, tunable coupling are demonstrated. The first is through different strain-induced energy shifts for the two QDs when the cantilever vibrates, resulting in changes to the exchange interaction. The second is through a laser-driven AC Stark shift that is sensitive to strain-induced shifts of the optical transitions. Both of these mechanisms can be tuned to zero with electrical bias or laser power, respectively, and give large spin-mechanical coupling strengths.
ABSTRACT
The quest for an integrated quantum optics platform has motivated the field of semiconductor quantum dot research for two decades. Demonstrations of quantum light sources, single photon switches, transistors and spin-photon interfaces have become very advanced. Yet the fundamental problem that every quantum dot is different prevents integration and scaling beyond a few quantum dots. Here, we address this challenge by patterning strain via local phase transitions to selectively tune individual quantum dots that are embedded in a photonic architecture. The patterning is implemented with in operando laser crystallization of a thin HfO2 film 'sheath' on the surface of a GaAs waveguide. Using this approach, we tune InAs quantum dot emission energies over the full inhomogeneous distribution with a step size down to the homogeneous linewidth and a spatial resolution better than 1 µm. Using these capabilities, we tune multiple quantum dots into resonance within the same waveguide and demonstrate a quantum interaction via superradiant emission from three quantum dots.
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This paper investigates the influence of two types of gait perturbation (i.e., trip and slip) induced by a programmable split-belt treadmill on the body's compensatory responses. Our fall-inducing technology equipped with a commercially available programmable split-belt treadmill provides unpredictable trip and slip perturbations during walking. Two force plates beneath the split-belt treadmill and a motion capture system quantify the body's kinetic and kinematic behaviors, and a wireless surface electromyography (EMG) system evaluates the lower limb muscle activity. Twenty healthy young adults participated. The perturbations (i.e., trip and slip) were applied randomly to the participant's left foot between the 31st and 40th steps. The kinetic and kinematic behaviors and lower limb muscle activity were assessed during the standing, walking, and recovery periods. Compared with trip perturbations, stepping responses to slip perturbations were quicker and trunk, shoulder, and whole body center of mass movements after slip perturbations were higher; the EMG results showed that tibialis anterior, gastrocnemius, rectus femoris, and biceps femoris activities were also higher. The two common types of gait perturbation (i.e., trip and slip) induced by a commercially available programmable split-belt treadmill influenced the body's compensatory responses.
Subject(s)
Accidental Falls , Biomechanical Phenomena , Electromyography , Female , Gait , Healthy Volunteers , Humans , Lower Extremity/physiology , Male , Muscle, Skeletal/physiology , Postural Balance , Shoulder , Torso , Walking , Young AdultABSTRACT
Two semiconductor optical frequency combs, consuming less than 1 W of electrical power, are used to demonstrate high-sensitivity mid-infrared dual-comb spectroscopy in the important 3-4 µm spectral region. The devices are 4 mm long by 4 µm wide, and each emits 8 mW of average optical power. The spectroscopic sensing performance is demonstrated by measurements of methane and hydrogen chloride with optical multi-pass cell sensitivity enhancement. The system provides a spectral coverage of 33 cm-1 (1 THz), 0.32 cm-1 (9.7 GHz) frequency sampling interval, and peak signal-to-noise ratio of â¼100 at 100 µs integration time. The monolithic design, low drive power, and direct generation of mid-infrared radiation are highly attractive for portable broadband spectroscopic instrumentation in future terrestrial and space applications.
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We report resonant-cavity infrared detectors with 34% external quantum efficiency at room temperature at the resonant wavelength of 4.0 µm, even though the absorber consists of only five quantum wells with a total thickness of 50 nm. The full width at half maximum (FWHM) linewidth is 46 nm, and the peak absorption is enhanced by nearly a factor of 30 over that for a single pass through the absorber. In spite of an unfavorable Shockley-Read lifetime in the current material, the dark current density is at the level of state-of-the-art HgCdTe detectors as quantified by "Rule 07." The Johnson-noise limited detectivity (D*) at 21°C is 7 × 109 cm Hz½/W. We expect that future improvements in the device design and material quality will lead to higher quantum efficiency, as well as a significant reduction of the dark current density consistent with the very thin absorber.
ABSTRACT
Since their inception, optical frequency combs have transformed a broad range of technical and scientific disciplines, spanning time keeping to navigation. Recently, dual comb spectroscopy has emerged as an attractive alternative to traditional Fourier transform spectroscopy, since it offers higher measurement sensitivity in a fraction of the time. Midwave infrared (mid-IR) frequency combs are especially promising as an effective means for probing the strong fundamental absorption lines of numerous chemical and biological agents. Mid-IR combs have been realized via frequency down-conversion of a near-IR comb, by optical pumping of a micro-resonator, and beyond 7 µm by four-wave mixing in a quantum cascade laser. In this work, we demonstrate an electrically-driven frequency comb source that spans more than 1 THz of bandwidth centered near 3.6 µm. This is achieved by passively mode-locking an interband cascade laser (ICL) with gain and saturable absorber sections monolithically integrated on the same chip. The new source will significantly enhance the capabilities of mid-IR multi-heterodyne frequency comb spectroscopy systems.
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A photoacoustic module (PAM) for methane detection was developed by combining a novel 3.2 µm interband cascade light emitting device (ICLED) with a compact differential photoacoustic cell. The ICLED with a 22-stage interband cascade active core emitted a collimated power of ~700 µW. A concave Al-coat reflector was positioned adjacent to the photoacoustic cell to enhance the gas absorption length. Assembly of the ICLED and reflector with the photoacoustic cell resulted in a robust and portable PAM without any moving parts. The PAM performance was evaluated in terms of operating pressure, sensitivity and linearity. A 1σ detection limit of 3.6 ppmv was achieved with a 1-s integration time.
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Little is known about the characteristics that make patients with acute leukemia suitable for undergoing salvage therapy by allogeneic hematopoietic stem cell transplantation (allo-HSCT). Here, we analyzed the clinical outcomes of 223 patients with acute leukemia who underwent allo-HSCT while not in complete remission (CR). The primary end points were overall survival (OS) and CR rate. CR was achieved in 79.8% of patients after allo-HSCT. Acute graft-versus-host disease (GVHD) was significantly associated with CR (P = 0.045). During a median follow-up of 30.1 months, the median OS was 6.1 months. OS was significantly longer in patients with good or standard risk cytogenetic characteristics than in those with poor risk cytogenetic characteristics (P = 0.029, P = 0.030, respectively). Patients who received allo-HSCT from a matched sibling donor had better survival than those with unrelated donors (P = 0.015). Primary chemorefractoriness was not associated with poor survival (P = 0.071). The number of chemotherapies before allo-HSCT was significantly correlated with outcome (P = 0.006). Chronic GVHD was a strong predictor of a longer OS (P = 0.025). In conclusion, survival of patients with primary chemorefractory acute leukemia is not lower when treated upfront with allo-HSCT. Hence, allo-HSCT should be actively considered in such patients. Acute and chronic GVHD is associated with better outcomes patients with acute leukemia who have undergone allo-HSCT and not achieved CR.
Subject(s)
Graft vs Host Disease/diagnosis , Graft vs Host Disease/therapy , Hematopoietic Stem Cell Transplantation/methods , Leukemia/diagnosis , Leukemia/therapy , Salvage Therapy/methods , Acute Disease , Adult , Female , Graft vs Host Disease/mortality , Hematopoietic Stem Cell Transplantation/mortality , Humans , Leukemia/mortality , Male , Middle Aged , Republic of Korea/epidemiology , Retrospective Studies , Salvage Therapy/mortality , Survival Rate/trends , Transplantation, HomologousABSTRACT
BACKGROUND: The Advanced Lung Cancer Inflammation Index (ALI, body mass index × albumin/neutrophil-to-lymphocyte ratio) has been demonstrated to be a prognostic factor of survival in some solid cancers. We retrospectively investigated the usefulness of the ALI to predict chemotherapy response and survival in 212 patients with diffuse large B cell lymphoma (DLBCL) treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy. METHODS: Patients were allocated to a low ALI group (n = 82, 38.7%) or a high ALI group (n = 130, 61.3%) according to an optimal pretreatment ALI cut-off value of 15.5 as determined by receiver operating curve analysis. RESULTS: The low ALI group displayed more adverse clinical characteristics, lower rates of complete remission (54.9 vs. 75.4%, p = 0.008), and poorer 5-year progression-free (PFS, 58.1 vs. 77.3%, p = 0.006) and overall (OS, 64.2 vs. 80.2%, p = 0.008) survival. Multivariate analysis showed that low ALI was found to independently predict shorter PFS and OS. Interestingly, a low ALI reverted to a high ALI during treatment in 58 patients (27.4%), and the 5-year OS of these patients was better than that of patients whose ALI remained low (n = 24, 72.5 vs. 24%, p < 0.001). CONCLUSIONS: ALI might be an easily available marker for predicting clinical outcomes in DLBCL patients treated with R-CHOP chemotherapy.